Eric Lee / linux-smarc-t335x-v3.2

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Commit c4e7893ebc3a5c507b53f59b9de448db20849944

Authored by Vivek Goyal
Committed by Jens Axboe
1 parent 80bdf0c78f
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

cfq-iosched: blktrace print per slice sector stats 

o Divyesh had gotten rid of this code in the past. I want to re-introduce it
  back as it helps me a lot during debugging.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Divyesh Shah <dpshah@google.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

Showing 1 changed file with 7 additions and 2 deletions Inline Diff

1 /* 1 /*
2 * CFQ, or complete fairness queueing, disk scheduler. 2 * CFQ, or complete fairness queueing, disk scheduler.
3 * 3 *
4 * Based on ideas from a previously unfinished io 4 * Based on ideas from a previously unfinished io
5 * scheduler (round robin per-process disk scheduling) and Andrea Arcangeli. 5 * scheduler (round robin per-process disk scheduling) and Andrea Arcangeli.
6 * 6 *
7 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> 7 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
8 */ 8 */
9 #include <linux/module.h> 9 #include <linux/module.h>
10 #include <linux/slab.h> 10 #include <linux/slab.h>
11 #include <linux/blkdev.h> 11 #include <linux/blkdev.h>
12 #include <linux/elevator.h> 12 #include <linux/elevator.h>
13 #include <linux/jiffies.h> 13 #include <linux/jiffies.h>
14 #include <linux/rbtree.h> 14 #include <linux/rbtree.h>
15 #include <linux/ioprio.h> 15 #include <linux/ioprio.h>
16 #include <linux/blktrace_api.h> 16 #include <linux/blktrace_api.h>
17 #include "cfq.h" 17 #include "cfq.h"
18 18
19 /* 19 /*
20 * tunables 20 * tunables
21 */ 21 */
22 /* max queue in one round of service */ 22 /* max queue in one round of service */
23 static const int cfq_quantum = 8; 23 static const int cfq_quantum = 8;
24 static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; 24 static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 };
25 /* maximum backwards seek, in KiB */ 25 /* maximum backwards seek, in KiB */
26 static const int cfq_back_max = 16 * 1024; 26 static const int cfq_back_max = 16 * 1024;
27 /* penalty of a backwards seek */ 27 /* penalty of a backwards seek */
28 static const int cfq_back_penalty = 2; 28 static const int cfq_back_penalty = 2;
29 static const int cfq_slice_sync = HZ / 10; 29 static const int cfq_slice_sync = HZ / 10;
30 static int cfq_slice_async = HZ / 25; 30 static int cfq_slice_async = HZ / 25;
31 static const int cfq_slice_async_rq = 2; 31 static const int cfq_slice_async_rq = 2;
32 static int cfq_slice_idle = HZ / 125; 32 static int cfq_slice_idle = HZ / 125;
33 static int cfq_group_idle = HZ / 125; 33 static int cfq_group_idle = HZ / 125;
34 static const int cfq_target_latency = HZ * 3/10; /* 300 ms */ 34 static const int cfq_target_latency = HZ * 3/10; /* 300 ms */
35 static const int cfq_hist_divisor = 4; 35 static const int cfq_hist_divisor = 4;
36 36
37 /* 37 /*
38 * offset from end of service tree 38 * offset from end of service tree
39 */ 39 */
40 #define CFQ_IDLE_DELAY (HZ / 5) 40 #define CFQ_IDLE_DELAY (HZ / 5)
41 41
42 /* 42 /*
43 * below this threshold, we consider thinktime immediate 43 * below this threshold, we consider thinktime immediate
44 */ 44 */
45 #define CFQ_MIN_TT (2) 45 #define CFQ_MIN_TT (2)
46 46
47 #define CFQ_SLICE_SCALE (5) 47 #define CFQ_SLICE_SCALE (5)
48 #define CFQ_HW_QUEUE_MIN (5) 48 #define CFQ_HW_QUEUE_MIN (5)
49 #define CFQ_SERVICE_SHIFT 12 49 #define CFQ_SERVICE_SHIFT 12
50 50
51 #define CFQQ_SEEK_THR (sector_t)(8 * 100) 51 #define CFQQ_SEEK_THR (sector_t)(8 * 100)
52 #define CFQQ_CLOSE_THR (sector_t)(8 * 1024) 52 #define CFQQ_CLOSE_THR (sector_t)(8 * 1024)
53 #define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32) 53 #define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32)
54 #define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8) 54 #define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8)
55 55
56 #define RQ_CIC(rq) \ 56 #define RQ_CIC(rq) \
57 ((struct cfq_io_context *) (rq)->elevator_private) 57 ((struct cfq_io_context *) (rq)->elevator_private)
58 #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2) 58 #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2)
59 #define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elevator_private3) 59 #define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elevator_private3)
60 60
61 static struct kmem_cache *cfq_pool; 61 static struct kmem_cache *cfq_pool;
62 static struct kmem_cache *cfq_ioc_pool; 62 static struct kmem_cache *cfq_ioc_pool;
63 63
64 static DEFINE_PER_CPU(unsigned long, cfq_ioc_count); 64 static DEFINE_PER_CPU(unsigned long, cfq_ioc_count);
65 static struct completion *ioc_gone; 65 static struct completion *ioc_gone;
66 static DEFINE_SPINLOCK(ioc_gone_lock); 66 static DEFINE_SPINLOCK(ioc_gone_lock);
67 67
68 static DEFINE_SPINLOCK(cic_index_lock); 68 static DEFINE_SPINLOCK(cic_index_lock);
69 static DEFINE_IDA(cic_index_ida); 69 static DEFINE_IDA(cic_index_ida);
70 70
71 #define CFQ_PRIO_LISTS IOPRIO_BE_NR 71 #define CFQ_PRIO_LISTS IOPRIO_BE_NR
72 #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) 72 #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
73 #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) 73 #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT)
74 74
75 #define sample_valid(samples) ((samples) > 80) 75 #define sample_valid(samples) ((samples) > 80)
76 #define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node) 76 #define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node)
77 77
78 /* 78 /*
79 * Most of our rbtree usage is for sorting with min extraction, so 79 * Most of our rbtree usage is for sorting with min extraction, so
80 * if we cache the leftmost node we don't have to walk down the tree 80 * if we cache the leftmost node we don't have to walk down the tree
81 * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should 81 * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should
82 * move this into the elevator for the rq sorting as well. 82 * move this into the elevator for the rq sorting as well.
83 */ 83 */
84 struct cfq_rb_root { 84 struct cfq_rb_root {
85 struct rb_root rb; 85 struct rb_root rb;
86 struct rb_node *left; 86 struct rb_node *left;
87 unsigned count; 87 unsigned count;
88 unsigned total_weight; 88 unsigned total_weight;
89 u64 min_vdisktime; 89 u64 min_vdisktime;
90 struct rb_node *active; 90 struct rb_node *active;
91 }; 91 };
92 #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, .left = NULL, \ 92 #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, .left = NULL, \
93 .count = 0, .min_vdisktime = 0, } 93 .count = 0, .min_vdisktime = 0, }
94 94
95 /* 95 /*
96 * Per process-grouping structure 96 * Per process-grouping structure
97 */ 97 */
98 struct cfq_queue { 98 struct cfq_queue {
99 /* reference count */ 99 /* reference count */
100 atomic_t ref; 100 atomic_t ref;
101 /* various state flags, see below */ 101 /* various state flags, see below */
102 unsigned int flags; 102 unsigned int flags;
103 /* parent cfq_data */ 103 /* parent cfq_data */
104 struct cfq_data *cfqd; 104 struct cfq_data *cfqd;
105 /* service_tree member */ 105 /* service_tree member */
106 struct rb_node rb_node; 106 struct rb_node rb_node;
107 /* service_tree key */ 107 /* service_tree key */
108 unsigned long rb_key; 108 unsigned long rb_key;
109 /* prio tree member */ 109 /* prio tree member */
110 struct rb_node p_node; 110 struct rb_node p_node;
111 /* prio tree root we belong to, if any */ 111 /* prio tree root we belong to, if any */
112 struct rb_root *p_root; 112 struct rb_root *p_root;
113 /* sorted list of pending requests */ 113 /* sorted list of pending requests */
114 struct rb_root sort_list; 114 struct rb_root sort_list;
115 /* if fifo isn't expired, next request to serve */ 115 /* if fifo isn't expired, next request to serve */
116 struct request *next_rq; 116 struct request *next_rq;
117 /* requests queued in sort_list */ 117 /* requests queued in sort_list */
118 int queued[2]; 118 int queued[2];
119 /* currently allocated requests */ 119 /* currently allocated requests */
120 int allocated[2]; 120 int allocated[2];
121 /* fifo list of requests in sort_list */ 121 /* fifo list of requests in sort_list */
122 struct list_head fifo; 122 struct list_head fifo;
123 123
124 /* time when queue got scheduled in to dispatch first request. */ 124 /* time when queue got scheduled in to dispatch first request. */
125 unsigned long dispatch_start; 125 unsigned long dispatch_start;
126 unsigned int allocated_slice; 126 unsigned int allocated_slice;
127 unsigned int slice_dispatch; 127 unsigned int slice_dispatch;
128 /* time when first request from queue completed and slice started. */ 128 /* time when first request from queue completed and slice started. */
129 unsigned long slice_start; 129 unsigned long slice_start;
130 unsigned long slice_end; 130 unsigned long slice_end;
131 long slice_resid; 131 long slice_resid;
132 132
133 /* pending metadata requests */ 133 /* pending metadata requests */
134 int meta_pending; 134 int meta_pending;
135 /* number of requests that are on the dispatch list or inside driver */ 135 /* number of requests that are on the dispatch list or inside driver */
136 int dispatched; 136 int dispatched;
137 137
138 /* io prio of this group */ 138 /* io prio of this group */
139 unsigned short ioprio, org_ioprio; 139 unsigned short ioprio, org_ioprio;
140 unsigned short ioprio_class, org_ioprio_class; 140 unsigned short ioprio_class, org_ioprio_class;
141 141
142 pid_t pid; 142 pid_t pid;
143 143
144 u32 seek_history; 144 u32 seek_history;
145 sector_t last_request_pos; 145 sector_t last_request_pos;
146 146
147 struct cfq_rb_root *service_tree; 147 struct cfq_rb_root *service_tree;
148 struct cfq_queue *new_cfqq; 148 struct cfq_queue *new_cfqq;
149 struct cfq_group *cfqg; 149 struct cfq_group *cfqg;
150 struct cfq_group *orig_cfqg; 150 struct cfq_group *orig_cfqg;
151 /* Number of sectors dispatched from queue in single dispatch round */
152 unsigned long nr_sectors;
151 }; 153 };
152 154
153 /* 155 /*
154 * First index in the service_trees. 156 * First index in the service_trees.
155 * IDLE is handled separately, so it has negative index 157 * IDLE is handled separately, so it has negative index
156 */ 158 */
157 enum wl_prio_t { 159 enum wl_prio_t {
158 BE_WORKLOAD = 0, 160 BE_WORKLOAD = 0,
159 RT_WORKLOAD = 1, 161 RT_WORKLOAD = 1,
160 IDLE_WORKLOAD = 2, 162 IDLE_WORKLOAD = 2,
161 }; 163 };
162 164
163 /* 165 /*
164 * Second index in the service_trees. 166 * Second index in the service_trees.
165 */ 167 */
166 enum wl_type_t { 168 enum wl_type_t {
167 ASYNC_WORKLOAD = 0, 169 ASYNC_WORKLOAD = 0,
168 SYNC_NOIDLE_WORKLOAD = 1, 170 SYNC_NOIDLE_WORKLOAD = 1,
169 SYNC_WORKLOAD = 2 171 SYNC_WORKLOAD = 2
170 }; 172 };
171 173
172 /* This is per cgroup per device grouping structure */ 174 /* This is per cgroup per device grouping structure */
173 struct cfq_group { 175 struct cfq_group {
174 /* group service_tree member */ 176 /* group service_tree member */
175 struct rb_node rb_node; 177 struct rb_node rb_node;
176 178
177 /* group service_tree key */ 179 /* group service_tree key */
178 u64 vdisktime; 180 u64 vdisktime;
179 unsigned int weight; 181 unsigned int weight;
180 bool on_st; 182 bool on_st;
181 183
182 /* number of cfqq currently on this group */ 184 /* number of cfqq currently on this group */
183 int nr_cfqq; 185 int nr_cfqq;
184 186
185 /* Per group busy queus average. Useful for workload slice calc. */ 187 /* Per group busy queus average. Useful for workload slice calc. */
186 unsigned int busy_queues_avg[2]; 188 unsigned int busy_queues_avg[2];
187 /* 189 /*
188 * rr lists of queues with requests, onle rr for each priority class. 190 * rr lists of queues with requests, onle rr for each priority class.
189 * Counts are embedded in the cfq_rb_root 191 * Counts are embedded in the cfq_rb_root
190 */ 192 */
191 struct cfq_rb_root service_trees[2][3]; 193 struct cfq_rb_root service_trees[2][3];
192 struct cfq_rb_root service_tree_idle; 194 struct cfq_rb_root service_tree_idle;
193 195
194 unsigned long saved_workload_slice; 196 unsigned long saved_workload_slice;
195 enum wl_type_t saved_workload; 197 enum wl_type_t saved_workload;
196 enum wl_prio_t saved_serving_prio; 198 enum wl_prio_t saved_serving_prio;
197 struct blkio_group blkg; 199 struct blkio_group blkg;
198 #ifdef CONFIG_CFQ_GROUP_IOSCHED 200 #ifdef CONFIG_CFQ_GROUP_IOSCHED
199 struct hlist_node cfqd_node; 201 struct hlist_node cfqd_node;
200 atomic_t ref; 202 atomic_t ref;
201 #endif 203 #endif
202 /* number of requests that are on the dispatch list or inside driver */ 204 /* number of requests that are on the dispatch list or inside driver */
203 int dispatched; 205 int dispatched;
204 }; 206 };
205 207
206 /* 208 /*
207 * Per block device queue structure 209 * Per block device queue structure
208 */ 210 */
209 struct cfq_data { 211 struct cfq_data {
210 struct request_queue *queue; 212 struct request_queue *queue;
211 /* Root service tree for cfq_groups */ 213 /* Root service tree for cfq_groups */
212 struct cfq_rb_root grp_service_tree; 214 struct cfq_rb_root grp_service_tree;
213 struct cfq_group root_group; 215 struct cfq_group root_group;
214 216
215 /* 217 /*
216 * The priority currently being served 218 * The priority currently being served
217 */ 219 */
218 enum wl_prio_t serving_prio; 220 enum wl_prio_t serving_prio;
219 enum wl_type_t serving_type; 221 enum wl_type_t serving_type;
220 unsigned long workload_expires; 222 unsigned long workload_expires;
221 struct cfq_group *serving_group; 223 struct cfq_group *serving_group;
222 bool noidle_tree_requires_idle; 224 bool noidle_tree_requires_idle;
223 225
224 /* 226 /*
225 * Each priority tree is sorted by next_request position. These 227 * Each priority tree is sorted by next_request position. These
226 * trees are used when determining if two or more queues are 228 * trees are used when determining if two or more queues are
227 * interleaving requests (see cfq_close_cooperator). 229 * interleaving requests (see cfq_close_cooperator).
228 */ 230 */
229 struct rb_root prio_trees[CFQ_PRIO_LISTS]; 231 struct rb_root prio_trees[CFQ_PRIO_LISTS];
230 232
231 unsigned int busy_queues; 233 unsigned int busy_queues;
232 234
233 int rq_in_driver; 235 int rq_in_driver;
234 int rq_in_flight[2]; 236 int rq_in_flight[2];
235 237
236 /* 238 /*
237 * queue-depth detection 239 * queue-depth detection
238 */ 240 */
239 int rq_queued; 241 int rq_queued;
240 int hw_tag; 242 int hw_tag;
241 /* 243 /*
242 * hw_tag can be 244 * hw_tag can be
243 * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection) 245 * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection)
244 * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth) 246 * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth)
245 * 0 => no NCQ 247 * 0 => no NCQ
246 */ 248 */
247 int hw_tag_est_depth; 249 int hw_tag_est_depth;
248 unsigned int hw_tag_samples; 250 unsigned int hw_tag_samples;
249 251
250 /* 252 /*
251 * idle window management 253 * idle window management
252 */ 254 */
253 struct timer_list idle_slice_timer; 255 struct timer_list idle_slice_timer;
254 struct work_struct unplug_work; 256 struct work_struct unplug_work;
255 257
256 struct cfq_queue *active_queue; 258 struct cfq_queue *active_queue;
257 struct cfq_io_context *active_cic; 259 struct cfq_io_context *active_cic;
258 260
259 /* 261 /*
260 * async queue for each priority case 262 * async queue for each priority case
261 */ 263 */
262 struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; 264 struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR];
263 struct cfq_queue *async_idle_cfqq; 265 struct cfq_queue *async_idle_cfqq;
264 266
265 sector_t last_position; 267 sector_t last_position;
266 268
267 /* 269 /*
268 * tunables, see top of file 270 * tunables, see top of file
269 */ 271 */
270 unsigned int cfq_quantum; 272 unsigned int cfq_quantum;
271 unsigned int cfq_fifo_expire[2]; 273 unsigned int cfq_fifo_expire[2];
272 unsigned int cfq_back_penalty; 274 unsigned int cfq_back_penalty;
273 unsigned int cfq_back_max; 275 unsigned int cfq_back_max;
274 unsigned int cfq_slice[2]; 276 unsigned int cfq_slice[2];
275 unsigned int cfq_slice_async_rq; 277 unsigned int cfq_slice_async_rq;
276 unsigned int cfq_slice_idle; 278 unsigned int cfq_slice_idle;
277 unsigned int cfq_group_idle; 279 unsigned int cfq_group_idle;
278 unsigned int cfq_latency; 280 unsigned int cfq_latency;
279 unsigned int cfq_group_isolation; 281 unsigned int cfq_group_isolation;
280 282
281 unsigned int cic_index; 283 unsigned int cic_index;
282 struct list_head cic_list; 284 struct list_head cic_list;
283 285
284 /* 286 /*
285 * Fallback dummy cfqq for extreme OOM conditions 287 * Fallback dummy cfqq for extreme OOM conditions
286 */ 288 */
287 struct cfq_queue oom_cfqq; 289 struct cfq_queue oom_cfqq;
288 290
289 unsigned long last_delayed_sync; 291 unsigned long last_delayed_sync;
290 292
291 /* List of cfq groups being managed on this device*/ 293 /* List of cfq groups being managed on this device*/
292 struct hlist_head cfqg_list; 294 struct hlist_head cfqg_list;
293 struct rcu_head rcu; 295 struct rcu_head rcu;
294 }; 296 };
295 297
296 static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); 298 static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd);
297 299
298 static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg, 300 static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg,
299 enum wl_prio_t prio, 301 enum wl_prio_t prio,
300 enum wl_type_t type) 302 enum wl_type_t type)
301 { 303 {
302 if (!cfqg) 304 if (!cfqg)
303 return NULL; 305 return NULL;
304 306
305 if (prio == IDLE_WORKLOAD) 307 if (prio == IDLE_WORKLOAD)
306 return &cfqg->service_tree_idle; 308 return &cfqg->service_tree_idle;
307 309
308 return &cfqg->service_trees[prio][type]; 310 return &cfqg->service_trees[prio][type];
309 } 311 }
310 312
311 enum cfqq_state_flags { 313 enum cfqq_state_flags {
312 CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ 314 CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */
313 CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ 315 CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */
314 CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ 316 CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */
315 CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ 317 CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */
316 CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ 318 CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */
317 CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ 319 CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */
318 CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ 320 CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */
319 CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ 321 CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */
320 CFQ_CFQQ_FLAG_sync, /* synchronous queue */ 322 CFQ_CFQQ_FLAG_sync, /* synchronous queue */
321 CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ 323 CFQ_CFQQ_FLAG_coop, /* cfqq is shared */
322 CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */ 324 CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */
323 CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ 325 CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */
324 CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ 326 CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */
325 }; 327 };
326 328
327 #define CFQ_CFQQ_FNS(name) \ 329 #define CFQ_CFQQ_FNS(name) \
328 static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ 330 static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \
329 { \ 331 { \
330 (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ 332 (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \
331 } \ 333 } \
332 static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ 334 static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \
333 { \ 335 { \
334 (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ 336 (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \
335 } \ 337 } \
336 static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ 338 static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \
337 { \ 339 { \
338 return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ 340 return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \
339 } 341 }
340 342
341 CFQ_CFQQ_FNS(on_rr); 343 CFQ_CFQQ_FNS(on_rr);
342 CFQ_CFQQ_FNS(wait_request); 344 CFQ_CFQQ_FNS(wait_request);
343 CFQ_CFQQ_FNS(must_dispatch); 345 CFQ_CFQQ_FNS(must_dispatch);
344 CFQ_CFQQ_FNS(must_alloc_slice); 346 CFQ_CFQQ_FNS(must_alloc_slice);
345 CFQ_CFQQ_FNS(fifo_expire); 347 CFQ_CFQQ_FNS(fifo_expire);
346 CFQ_CFQQ_FNS(idle_window); 348 CFQ_CFQQ_FNS(idle_window);
347 CFQ_CFQQ_FNS(prio_changed); 349 CFQ_CFQQ_FNS(prio_changed);
348 CFQ_CFQQ_FNS(slice_new); 350 CFQ_CFQQ_FNS(slice_new);
349 CFQ_CFQQ_FNS(sync); 351 CFQ_CFQQ_FNS(sync);
350 CFQ_CFQQ_FNS(coop); 352 CFQ_CFQQ_FNS(coop);
351 CFQ_CFQQ_FNS(split_coop); 353 CFQ_CFQQ_FNS(split_coop);
352 CFQ_CFQQ_FNS(deep); 354 CFQ_CFQQ_FNS(deep);
353 CFQ_CFQQ_FNS(wait_busy); 355 CFQ_CFQQ_FNS(wait_busy);
354 #undef CFQ_CFQQ_FNS 356 #undef CFQ_CFQQ_FNS
355 357
356 #ifdef CONFIG_CFQ_GROUP_IOSCHED 358 #ifdef CONFIG_CFQ_GROUP_IOSCHED
357 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ 359 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
358 blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \ 360 blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \
359 cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ 361 cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
360 blkg_path(&(cfqq)->cfqg->blkg), ##args); 362 blkg_path(&(cfqq)->cfqg->blkg), ##args);
361 363
362 #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) \ 364 #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) \
363 blk_add_trace_msg((cfqd)->queue, "%s " fmt, \ 365 blk_add_trace_msg((cfqd)->queue, "%s " fmt, \
364 blkg_path(&(cfqg)->blkg), ##args); \ 366 blkg_path(&(cfqg)->blkg), ##args); \
365 367
366 #else 368 #else
367 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ 369 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
368 blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args) 370 blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args)
369 #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0); 371 #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0);
370 #endif 372 #endif
371 #define cfq_log(cfqd, fmt, args...) \ 373 #define cfq_log(cfqd, fmt, args...) \
372 blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) 374 blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args)
373 375
374 /* Traverses through cfq group service trees */ 376 /* Traverses through cfq group service trees */
375 #define for_each_cfqg_st(cfqg, i, j, st) \ 377 #define for_each_cfqg_st(cfqg, i, j, st) \
376 for (i = 0; i <= IDLE_WORKLOAD; i++) \ 378 for (i = 0; i <= IDLE_WORKLOAD; i++) \
377 for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ 379 for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\
378 : &cfqg->service_tree_idle; \ 380 : &cfqg->service_tree_idle; \
379 (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ 381 (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \
380 (i == IDLE_WORKLOAD && j == 0); \ 382 (i == IDLE_WORKLOAD && j == 0); \
381 j++, st = i < IDLE_WORKLOAD ? \ 383 j++, st = i < IDLE_WORKLOAD ? \
382 &cfqg->service_trees[i][j]: NULL) \ 384 &cfqg->service_trees[i][j]: NULL) \
383 385
384 386
385 static inline bool iops_mode(struct cfq_data *cfqd) 387 static inline bool iops_mode(struct cfq_data *cfqd)
386 { 388 {
387 /* 389 /*
388 * If we are not idling on queues and it is a NCQ drive, parallel 390 * If we are not idling on queues and it is a NCQ drive, parallel
389 * execution of requests is on and measuring time is not possible 391 * execution of requests is on and measuring time is not possible
390 * in most of the cases until and unless we drive shallower queue 392 * in most of the cases until and unless we drive shallower queue
391 * depths and that becomes a performance bottleneck. In such cases 393 * depths and that becomes a performance bottleneck. In such cases
392 * switch to start providing fairness in terms of number of IOs. 394 * switch to start providing fairness in terms of number of IOs.
393 */ 395 */
394 if (!cfqd->cfq_slice_idle && cfqd->hw_tag) 396 if (!cfqd->cfq_slice_idle && cfqd->hw_tag)
395 return true; 397 return true;
396 else 398 else
397 return false; 399 return false;
398 } 400 }
399 401
400 static inline enum wl_prio_t cfqq_prio(struct cfq_queue *cfqq) 402 static inline enum wl_prio_t cfqq_prio(struct cfq_queue *cfqq)
401 { 403 {
402 if (cfq_class_idle(cfqq)) 404 if (cfq_class_idle(cfqq))
403 return IDLE_WORKLOAD; 405 return IDLE_WORKLOAD;
404 if (cfq_class_rt(cfqq)) 406 if (cfq_class_rt(cfqq))
405 return RT_WORKLOAD; 407 return RT_WORKLOAD;
406 return BE_WORKLOAD; 408 return BE_WORKLOAD;
407 } 409 }
408 410
409 411
410 static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) 412 static enum wl_type_t cfqq_type(struct cfq_queue *cfqq)
411 { 413 {
412 if (!cfq_cfqq_sync(cfqq)) 414 if (!cfq_cfqq_sync(cfqq))
413 return ASYNC_WORKLOAD; 415 return ASYNC_WORKLOAD;
414 if (!cfq_cfqq_idle_window(cfqq)) 416 if (!cfq_cfqq_idle_window(cfqq))
415 return SYNC_NOIDLE_WORKLOAD; 417 return SYNC_NOIDLE_WORKLOAD;
416 return SYNC_WORKLOAD; 418 return SYNC_WORKLOAD;
417 } 419 }
418 420
419 static inline int cfq_group_busy_queues_wl(enum wl_prio_t wl, 421 static inline int cfq_group_busy_queues_wl(enum wl_prio_t wl,
420 struct cfq_data *cfqd, 422 struct cfq_data *cfqd,
421 struct cfq_group *cfqg) 423 struct cfq_group *cfqg)
422 { 424 {
423 if (wl == IDLE_WORKLOAD) 425 if (wl == IDLE_WORKLOAD)
424 return cfqg->service_tree_idle.count; 426 return cfqg->service_tree_idle.count;
425 427
426 return cfqg->service_trees[wl][ASYNC_WORKLOAD].count 428 return cfqg->service_trees[wl][ASYNC_WORKLOAD].count
427 + cfqg->service_trees[wl][SYNC_NOIDLE_WORKLOAD].count 429 + cfqg->service_trees[wl][SYNC_NOIDLE_WORKLOAD].count
428 + cfqg->service_trees[wl][SYNC_WORKLOAD].count; 430 + cfqg->service_trees[wl][SYNC_WORKLOAD].count;
429 } 431 }
430 432
431 static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, 433 static inline int cfqg_busy_async_queues(struct cfq_data *cfqd,
432 struct cfq_group *cfqg) 434 struct cfq_group *cfqg)
433 { 435 {
434 return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count 436 return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count
435 + cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count; 437 + cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count;
436 } 438 }
437 439
438 static void cfq_dispatch_insert(struct request_queue *, struct request *); 440 static void cfq_dispatch_insert(struct request_queue *, struct request *);
439 static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool, 441 static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool,
440 struct io_context *, gfp_t); 442 struct io_context *, gfp_t);
441 static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *, 443 static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *,
442 struct io_context *); 444 struct io_context *);
443 445
444 static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic, 446 static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic,
445 bool is_sync) 447 bool is_sync)
446 { 448 {
447 return cic->cfqq[is_sync]; 449 return cic->cfqq[is_sync];
448 } 450 }
449 451
450 static inline void cic_set_cfqq(struct cfq_io_context *cic, 452 static inline void cic_set_cfqq(struct cfq_io_context *cic,
451 struct cfq_queue *cfqq, bool is_sync) 453 struct cfq_queue *cfqq, bool is_sync)
452 { 454 {
453 cic->cfqq[is_sync] = cfqq; 455 cic->cfqq[is_sync] = cfqq;
454 } 456 }
455 457
456 #define CIC_DEAD_KEY 1ul 458 #define CIC_DEAD_KEY 1ul
457 #define CIC_DEAD_INDEX_SHIFT 1 459 #define CIC_DEAD_INDEX_SHIFT 1
458 460
459 static inline void *cfqd_dead_key(struct cfq_data *cfqd) 461 static inline void *cfqd_dead_key(struct cfq_data *cfqd)
460 { 462 {
461 return (void *)(cfqd->cic_index << CIC_DEAD_INDEX_SHIFT | CIC_DEAD_KEY); 463 return (void *)(cfqd->cic_index << CIC_DEAD_INDEX_SHIFT | CIC_DEAD_KEY);
462 } 464 }
463 465
464 static inline struct cfq_data *cic_to_cfqd(struct cfq_io_context *cic) 466 static inline struct cfq_data *cic_to_cfqd(struct cfq_io_context *cic)
465 { 467 {
466 struct cfq_data *cfqd = cic->key; 468 struct cfq_data *cfqd = cic->key;
467 469
468 if (unlikely((unsigned long) cfqd & CIC_DEAD_KEY)) 470 if (unlikely((unsigned long) cfqd & CIC_DEAD_KEY))
469 return NULL; 471 return NULL;
470 472
471 return cfqd; 473 return cfqd;
472 } 474 }
473 475
474 /* 476 /*
475 * We regard a request as SYNC, if it's either a read or has the SYNC bit 477 * We regard a request as SYNC, if it's either a read or has the SYNC bit
476 * set (in which case it could also be direct WRITE). 478 * set (in which case it could also be direct WRITE).
477 */ 479 */
478 static inline bool cfq_bio_sync(struct bio *bio) 480 static inline bool cfq_bio_sync(struct bio *bio)
479 { 481 {
480 return bio_data_dir(bio) == READ || (bio->bi_rw & REQ_SYNC); 482 return bio_data_dir(bio) == READ || (bio->bi_rw & REQ_SYNC);
481 } 483 }
482 484
483 /* 485 /*
484 * scheduler run of queue, if there are requests pending and no one in the 486 * scheduler run of queue, if there are requests pending and no one in the
485 * driver that will restart queueing 487 * driver that will restart queueing
486 */ 488 */
487 static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) 489 static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
488 { 490 {
489 if (cfqd->busy_queues) { 491 if (cfqd->busy_queues) {
490 cfq_log(cfqd, "schedule dispatch"); 492 cfq_log(cfqd, "schedule dispatch");
491 kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); 493 kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work);
492 } 494 }
493 } 495 }
494 496
495 static int cfq_queue_empty(struct request_queue *q) 497 static int cfq_queue_empty(struct request_queue *q)
496 { 498 {
497 struct cfq_data *cfqd = q->elevator->elevator_data; 499 struct cfq_data *cfqd = q->elevator->elevator_data;
498 500
499 return !cfqd->rq_queued; 501 return !cfqd->rq_queued;
500 } 502 }
501 503
502 /* 504 /*
503 * Scale schedule slice based on io priority. Use the sync time slice only 505 * Scale schedule slice based on io priority. Use the sync time slice only
504 * if a queue is marked sync and has sync io queued. A sync queue with async 506 * if a queue is marked sync and has sync io queued. A sync queue with async
505 * io only, should not get full sync slice length. 507 * io only, should not get full sync slice length.
506 */ 508 */
507 static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync, 509 static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync,
508 unsigned short prio) 510 unsigned short prio)
509 { 511 {
510 const int base_slice = cfqd->cfq_slice[sync]; 512 const int base_slice = cfqd->cfq_slice[sync];
511 513
512 WARN_ON(prio >= IOPRIO_BE_NR); 514 WARN_ON(prio >= IOPRIO_BE_NR);
513 515
514 return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); 516 return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio));
515 } 517 }
516 518
517 static inline int 519 static inline int
518 cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) 520 cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
519 { 521 {
520 return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); 522 return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio);
521 } 523 }
522 524
523 static inline u64 cfq_scale_slice(unsigned long delta, struct cfq_group *cfqg) 525 static inline u64 cfq_scale_slice(unsigned long delta, struct cfq_group *cfqg)
524 { 526 {
525 u64 d = delta << CFQ_SERVICE_SHIFT; 527 u64 d = delta << CFQ_SERVICE_SHIFT;
526 528
527 d = d * BLKIO_WEIGHT_DEFAULT; 529 d = d * BLKIO_WEIGHT_DEFAULT;
528 do_div(d, cfqg->weight); 530 do_div(d, cfqg->weight);
529 return d; 531 return d;
530 } 532 }
531 533
532 static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) 534 static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime)
533 { 535 {
534 s64 delta = (s64)(vdisktime - min_vdisktime); 536 s64 delta = (s64)(vdisktime - min_vdisktime);
535 if (delta > 0) 537 if (delta > 0)
536 min_vdisktime = vdisktime; 538 min_vdisktime = vdisktime;
537 539
538 return min_vdisktime; 540 return min_vdisktime;
539 } 541 }
540 542
541 static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) 543 static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime)
542 { 544 {
543 s64 delta = (s64)(vdisktime - min_vdisktime); 545 s64 delta = (s64)(vdisktime - min_vdisktime);
544 if (delta < 0) 546 if (delta < 0)
545 min_vdisktime = vdisktime; 547 min_vdisktime = vdisktime;
546 548
547 return min_vdisktime; 549 return min_vdisktime;
548 } 550 }
549 551
550 static void update_min_vdisktime(struct cfq_rb_root *st) 552 static void update_min_vdisktime(struct cfq_rb_root *st)
551 { 553 {
552 u64 vdisktime = st->min_vdisktime; 554 u64 vdisktime = st->min_vdisktime;
553 struct cfq_group *cfqg; 555 struct cfq_group *cfqg;
554 556
555 if (st->active) { 557 if (st->active) {
556 cfqg = rb_entry_cfqg(st->active); 558 cfqg = rb_entry_cfqg(st->active);
557 vdisktime = cfqg->vdisktime; 559 vdisktime = cfqg->vdisktime;
558 } 560 }
559 561
560 if (st->left) { 562 if (st->left) {
561 cfqg = rb_entry_cfqg(st->left); 563 cfqg = rb_entry_cfqg(st->left);
562 vdisktime = min_vdisktime(vdisktime, cfqg->vdisktime); 564 vdisktime = min_vdisktime(vdisktime, cfqg->vdisktime);
563 } 565 }
564 566
565 st->min_vdisktime = max_vdisktime(st->min_vdisktime, vdisktime); 567 st->min_vdisktime = max_vdisktime(st->min_vdisktime, vdisktime);
566 } 568 }
567 569
568 /* 570 /*
569 * get averaged number of queues of RT/BE priority. 571 * get averaged number of queues of RT/BE priority.
570 * average is updated, with a formula that gives more weight to higher numbers, 572 * average is updated, with a formula that gives more weight to higher numbers,
571 * to quickly follows sudden increases and decrease slowly 573 * to quickly follows sudden increases and decrease slowly
572 */ 574 */
573 575
574 static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, 576 static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd,
575 struct cfq_group *cfqg, bool rt) 577 struct cfq_group *cfqg, bool rt)
576 { 578 {
577 unsigned min_q, max_q; 579 unsigned min_q, max_q;
578 unsigned mult = cfq_hist_divisor - 1; 580 unsigned mult = cfq_hist_divisor - 1;
579 unsigned round = cfq_hist_divisor / 2; 581 unsigned round = cfq_hist_divisor / 2;
580 unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg); 582 unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg);
581 583
582 min_q = min(cfqg->busy_queues_avg[rt], busy); 584 min_q = min(cfqg->busy_queues_avg[rt], busy);
583 max_q = max(cfqg->busy_queues_avg[rt], busy); 585 max_q = max(cfqg->busy_queues_avg[rt], busy);
584 cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) / 586 cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) /
585 cfq_hist_divisor; 587 cfq_hist_divisor;
586 return cfqg->busy_queues_avg[rt]; 588 return cfqg->busy_queues_avg[rt];
587 } 589 }
588 590
589 static inline unsigned 591 static inline unsigned
590 cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) 592 cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg)
591 { 593 {
592 struct cfq_rb_root *st = &cfqd->grp_service_tree; 594 struct cfq_rb_root *st = &cfqd->grp_service_tree;
593 595
594 return cfq_target_latency * cfqg->weight / st->total_weight; 596 return cfq_target_latency * cfqg->weight / st->total_weight;
595 } 597 }
596 598
597 static inline void 599 static inline void
598 cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) 600 cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
599 { 601 {
600 unsigned slice = cfq_prio_to_slice(cfqd, cfqq); 602 unsigned slice = cfq_prio_to_slice(cfqd, cfqq);
601 if (cfqd->cfq_latency) { 603 if (cfqd->cfq_latency) {
602 /* 604 /*
603 * interested queues (we consider only the ones with the same 605 * interested queues (we consider only the ones with the same
604 * priority class in the cfq group) 606 * priority class in the cfq group)
605 */ 607 */
606 unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, 608 unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg,
607 cfq_class_rt(cfqq)); 609 cfq_class_rt(cfqq));
608 unsigned sync_slice = cfqd->cfq_slice[1]; 610 unsigned sync_slice = cfqd->cfq_slice[1];
609 unsigned expect_latency = sync_slice * iq; 611 unsigned expect_latency = sync_slice * iq;
610 unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg); 612 unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg);
611 613
612 if (expect_latency > group_slice) { 614 if (expect_latency > group_slice) {
613 unsigned base_low_slice = 2 * cfqd->cfq_slice_idle; 615 unsigned base_low_slice = 2 * cfqd->cfq_slice_idle;
614 /* scale low_slice according to IO priority 616 /* scale low_slice according to IO priority
615 * and sync vs async */ 617 * and sync vs async */
616 unsigned low_slice = 618 unsigned low_slice =
617 min(slice, base_low_slice * slice / sync_slice); 619 min(slice, base_low_slice * slice / sync_slice);
618 /* the adapted slice value is scaled to fit all iqs 620 /* the adapted slice value is scaled to fit all iqs
619 * into the target latency */ 621 * into the target latency */
620 slice = max(slice * group_slice / expect_latency, 622 slice = max(slice * group_slice / expect_latency,
621 low_slice); 623 low_slice);
622 } 624 }
623 } 625 }
624 cfqq->slice_start = jiffies; 626 cfqq->slice_start = jiffies;
625 cfqq->slice_end = jiffies + slice; 627 cfqq->slice_end = jiffies + slice;
626 cfqq->allocated_slice = slice; 628 cfqq->allocated_slice = slice;
627 cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); 629 cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies);
628 } 630 }
629 631
630 /* 632 /*
631 * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end 633 * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end
632 * isn't valid until the first request from the dispatch is activated 634 * isn't valid until the first request from the dispatch is activated
633 * and the slice time set. 635 * and the slice time set.
634 */ 636 */
635 static inline bool cfq_slice_used(struct cfq_queue *cfqq) 637 static inline bool cfq_slice_used(struct cfq_queue *cfqq)
636 { 638 {
637 if (cfq_cfqq_slice_new(cfqq)) 639 if (cfq_cfqq_slice_new(cfqq))
638 return 0; 640 return 0;
639 if (time_before(jiffies, cfqq->slice_end)) 641 if (time_before(jiffies, cfqq->slice_end))
640 return 0; 642 return 0;
641 643
642 return 1; 644 return 1;
643 } 645 }
644 646
645 /* 647 /*
646 * Lifted from AS - choose which of rq1 and rq2 that is best served now. 648 * Lifted from AS - choose which of rq1 and rq2 that is best served now.
647 * We choose the request that is closest to the head right now. Distance 649 * We choose the request that is closest to the head right now. Distance
648 * behind the head is penalized and only allowed to a certain extent. 650 * behind the head is penalized and only allowed to a certain extent.
649 */ 651 */
650 static struct request * 652 static struct request *
651 cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last) 653 cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last)
652 { 654 {
653 sector_t s1, s2, d1 = 0, d2 = 0; 655 sector_t s1, s2, d1 = 0, d2 = 0;
654 unsigned long back_max; 656 unsigned long back_max;
655 #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ 657 #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */
656 #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ 658 #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */
657 unsigned wrap = 0; /* bit mask: requests behind the disk head? */ 659 unsigned wrap = 0; /* bit mask: requests behind the disk head? */
658 660
659 if (rq1 == NULL || rq1 == rq2) 661 if (rq1 == NULL || rq1 == rq2)
660 return rq2; 662 return rq2;
661 if (rq2 == NULL) 663 if (rq2 == NULL)
662 return rq1; 664 return rq1;
663 665
664 if (rq_is_sync(rq1) && !rq_is_sync(rq2)) 666 if (rq_is_sync(rq1) && !rq_is_sync(rq2))
665 return rq1; 667 return rq1;
666 else if (rq_is_sync(rq2) && !rq_is_sync(rq1)) 668 else if (rq_is_sync(rq2) && !rq_is_sync(rq1))
667 return rq2; 669 return rq2;
668 if ((rq1->cmd_flags & REQ_META) && !(rq2->cmd_flags & REQ_META)) 670 if ((rq1->cmd_flags & REQ_META) && !(rq2->cmd_flags & REQ_META))
669 return rq1; 671 return rq1;
670 else if ((rq2->cmd_flags & REQ_META) && 672 else if ((rq2->cmd_flags & REQ_META) &&
671 !(rq1->cmd_flags & REQ_META)) 673 !(rq1->cmd_flags & REQ_META))
672 return rq2; 674 return rq2;
673 675
674 s1 = blk_rq_pos(rq1); 676 s1 = blk_rq_pos(rq1);
675 s2 = blk_rq_pos(rq2); 677 s2 = blk_rq_pos(rq2);
676 678
677 /* 679 /*
678 * by definition, 1KiB is 2 sectors 680 * by definition, 1KiB is 2 sectors
679 */ 681 */
680 back_max = cfqd->cfq_back_max * 2; 682 back_max = cfqd->cfq_back_max * 2;
681 683
682 /* 684 /*
683 * Strict one way elevator _except_ in the case where we allow 685 * Strict one way elevator _except_ in the case where we allow
684 * short backward seeks which are biased as twice the cost of a 686 * short backward seeks which are biased as twice the cost of a
685 * similar forward seek. 687 * similar forward seek.
686 */ 688 */
687 if (s1 >= last) 689 if (s1 >= last)
688 d1 = s1 - last; 690 d1 = s1 - last;
689 else if (s1 + back_max >= last) 691 else if (s1 + back_max >= last)
690 d1 = (last - s1) * cfqd->cfq_back_penalty; 692 d1 = (last - s1) * cfqd->cfq_back_penalty;
691 else 693 else
692 wrap |= CFQ_RQ1_WRAP; 694 wrap |= CFQ_RQ1_WRAP;
693 695
694 if (s2 >= last) 696 if (s2 >= last)
695 d2 = s2 - last; 697 d2 = s2 - last;
696 else if (s2 + back_max >= last) 698 else if (s2 + back_max >= last)
697 d2 = (last - s2) * cfqd->cfq_back_penalty; 699 d2 = (last - s2) * cfqd->cfq_back_penalty;
698 else 700 else
699 wrap |= CFQ_RQ2_WRAP; 701 wrap |= CFQ_RQ2_WRAP;
700 702
701 /* Found required data */ 703 /* Found required data */
702 704
703 /* 705 /*
704 * By doing switch() on the bit mask "wrap" we avoid having to 706 * By doing switch() on the bit mask "wrap" we avoid having to
705 * check two variables for all permutations: --> faster! 707 * check two variables for all permutations: --> faster!
706 */ 708 */
707 switch (wrap) { 709 switch (wrap) {
708 case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ 710 case 0: /* common case for CFQ: rq1 and rq2 not wrapped */
709 if (d1 < d2) 711 if (d1 < d2)
710 return rq1; 712 return rq1;
711 else if (d2 < d1) 713 else if (d2 < d1)
712 return rq2; 714 return rq2;
713 else { 715 else {
714 if (s1 >= s2) 716 if (s1 >= s2)
715 return rq1; 717 return rq1;
716 else 718 else
717 return rq2; 719 return rq2;
718 } 720 }
719 721
720 case CFQ_RQ2_WRAP: 722 case CFQ_RQ2_WRAP:
721 return rq1; 723 return rq1;
722 case CFQ_RQ1_WRAP: 724 case CFQ_RQ1_WRAP:
723 return rq2; 725 return rq2;
724 case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ 726 case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */
725 default: 727 default:
726 /* 728 /*
727 * Since both rqs are wrapped, 729 * Since both rqs are wrapped,
728 * start with the one that's further behind head 730 * start with the one that's further behind head
729 * (--> only *one* back seek required), 731 * (--> only *one* back seek required),
730 * since back seek takes more time than forward. 732 * since back seek takes more time than forward.
731 */ 733 */
732 if (s1 <= s2) 734 if (s1 <= s2)
733 return rq1; 735 return rq1;
734 else 736 else
735 return rq2; 737 return rq2;
736 } 738 }
737 } 739 }
738 740
739 /* 741 /*
740 * The below is leftmost cache rbtree addon 742 * The below is leftmost cache rbtree addon
741 */ 743 */
742 static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) 744 static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
743 { 745 {
744 /* Service tree is empty */ 746 /* Service tree is empty */
745 if (!root->count) 747 if (!root->count)
746 return NULL; 748 return NULL;
747 749
748 if (!root->left) 750 if (!root->left)
749 root->left = rb_first(&root->rb); 751 root->left = rb_first(&root->rb);
750 752
751 if (root->left) 753 if (root->left)
752 return rb_entry(root->left, struct cfq_queue, rb_node); 754 return rb_entry(root->left, struct cfq_queue, rb_node);
753 755
754 return NULL; 756 return NULL;
755 } 757 }
756 758
757 static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) 759 static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root)
758 { 760 {
759 if (!root->left) 761 if (!root->left)
760 root->left = rb_first(&root->rb); 762 root->left = rb_first(&root->rb);
761 763
762 if (root->left) 764 if (root->left)
763 return rb_entry_cfqg(root->left); 765 return rb_entry_cfqg(root->left);
764 766
765 return NULL; 767 return NULL;
766 } 768 }
767 769
768 static void rb_erase_init(struct rb_node *n, struct rb_root *root) 770 static void rb_erase_init(struct rb_node *n, struct rb_root *root)
769 { 771 {
770 rb_erase(n, root); 772 rb_erase(n, root);
771 RB_CLEAR_NODE(n); 773 RB_CLEAR_NODE(n);
772 } 774 }
773 775
774 static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) 776 static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root)
775 { 777 {
776 if (root->left == n) 778 if (root->left == n)
777 root->left = NULL; 779 root->left = NULL;
778 rb_erase_init(n, &root->rb); 780 rb_erase_init(n, &root->rb);
779 --root->count; 781 --root->count;
780 } 782 }
781 783
782 /* 784 /*
783 * would be nice to take fifo expire time into account as well 785 * would be nice to take fifo expire time into account as well
784 */ 786 */
785 static struct request * 787 static struct request *
786 cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, 788 cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
787 struct request *last) 789 struct request *last)
788 { 790 {
789 struct rb_node *rbnext = rb_next(&last->rb_node); 791 struct rb_node *rbnext = rb_next(&last->rb_node);
790 struct rb_node *rbprev = rb_prev(&last->rb_node); 792 struct rb_node *rbprev = rb_prev(&last->rb_node);
791 struct request *next = NULL, *prev = NULL; 793 struct request *next = NULL, *prev = NULL;
792 794
793 BUG_ON(RB_EMPTY_NODE(&last->rb_node)); 795 BUG_ON(RB_EMPTY_NODE(&last->rb_node));
794 796
795 if (rbprev) 797 if (rbprev)
796 prev = rb_entry_rq(rbprev); 798 prev = rb_entry_rq(rbprev);
797 799
798 if (rbnext) 800 if (rbnext)
799 next = rb_entry_rq(rbnext); 801 next = rb_entry_rq(rbnext);
800 else { 802 else {
801 rbnext = rb_first(&cfqq->sort_list); 803 rbnext = rb_first(&cfqq->sort_list);
802 if (rbnext && rbnext != &last->rb_node) 804 if (rbnext && rbnext != &last->rb_node)
803 next = rb_entry_rq(rbnext); 805 next = rb_entry_rq(rbnext);
804 } 806 }
805 807
806 return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); 808 return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last));
807 } 809 }
808 810
809 static unsigned long cfq_slice_offset(struct cfq_data *cfqd, 811 static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
810 struct cfq_queue *cfqq) 812 struct cfq_queue *cfqq)
811 { 813 {
812 /* 814 /*
813 * just an approximation, should be ok. 815 * just an approximation, should be ok.
814 */ 816 */
815 return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - 817 return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) -
816 cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); 818 cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio));
817 } 819 }
818 820
819 static inline s64 821 static inline s64
820 cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) 822 cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg)
821 { 823 {
822 return cfqg->vdisktime - st->min_vdisktime; 824 return cfqg->vdisktime - st->min_vdisktime;
823 } 825 }
824 826
825 static void 827 static void
826 __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) 828 __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
827 { 829 {
828 struct rb_node **node = &st->rb.rb_node; 830 struct rb_node **node = &st->rb.rb_node;
829 struct rb_node *parent = NULL; 831 struct rb_node *parent = NULL;
830 struct cfq_group *__cfqg; 832 struct cfq_group *__cfqg;
831 s64 key = cfqg_key(st, cfqg); 833 s64 key = cfqg_key(st, cfqg);
832 int left = 1; 834 int left = 1;
833 835
834 while (*node != NULL) { 836 while (*node != NULL) {
835 parent = *node; 837 parent = *node;
836 __cfqg = rb_entry_cfqg(parent); 838 __cfqg = rb_entry_cfqg(parent);
837 839
838 if (key < cfqg_key(st, __cfqg)) 840 if (key < cfqg_key(st, __cfqg))
839 node = &parent->rb_left; 841 node = &parent->rb_left;
840 else { 842 else {
841 node = &parent->rb_right; 843 node = &parent->rb_right;
842 left = 0; 844 left = 0;
843 } 845 }
844 } 846 }
845 847
846 if (left) 848 if (left)
847 st->left = &cfqg->rb_node; 849 st->left = &cfqg->rb_node;
848 850
849 rb_link_node(&cfqg->rb_node, parent, node); 851 rb_link_node(&cfqg->rb_node, parent, node);
850 rb_insert_color(&cfqg->rb_node, &st->rb); 852 rb_insert_color(&cfqg->rb_node, &st->rb);
851 } 853 }
852 854
853 static void 855 static void
854 cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg) 856 cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
855 { 857 {
856 struct cfq_rb_root *st = &cfqd->grp_service_tree; 858 struct cfq_rb_root *st = &cfqd->grp_service_tree;
857 struct cfq_group *__cfqg; 859 struct cfq_group *__cfqg;
858 struct rb_node *n; 860 struct rb_node *n;
859 861
860 cfqg->nr_cfqq++; 862 cfqg->nr_cfqq++;
861 if (cfqg->on_st) 863 if (cfqg->on_st)
862 return; 864 return;
863 865
864 /* 866 /*
865 * Currently put the group at the end. Later implement something 867 * Currently put the group at the end. Later implement something
866 * so that groups get lesser vtime based on their weights, so that 868 * so that groups get lesser vtime based on their weights, so that
867 * if group does not loose all if it was not continously backlogged. 869 * if group does not loose all if it was not continously backlogged.
868 */ 870 */
869 n = rb_last(&st->rb); 871 n = rb_last(&st->rb);
870 if (n) { 872 if (n) {
871 __cfqg = rb_entry_cfqg(n); 873 __cfqg = rb_entry_cfqg(n);
872 cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY; 874 cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY;
873 } else 875 } else
874 cfqg->vdisktime = st->min_vdisktime; 876 cfqg->vdisktime = st->min_vdisktime;
875 877
876 __cfq_group_service_tree_add(st, cfqg); 878 __cfq_group_service_tree_add(st, cfqg);
877 cfqg->on_st = true; 879 cfqg->on_st = true;
878 st->total_weight += cfqg->weight; 880 st->total_weight += cfqg->weight;
879 } 881 }
880 882
881 static void 883 static void
882 cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg) 884 cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
883 { 885 {
884 struct cfq_rb_root *st = &cfqd->grp_service_tree; 886 struct cfq_rb_root *st = &cfqd->grp_service_tree;
885 887
886 if (st->active == &cfqg->rb_node) 888 if (st->active == &cfqg->rb_node)
887 st->active = NULL; 889 st->active = NULL;
888 890
889 BUG_ON(cfqg->nr_cfqq < 1); 891 BUG_ON(cfqg->nr_cfqq < 1);
890 cfqg->nr_cfqq--; 892 cfqg->nr_cfqq--;
891 893
892 /* If there are other cfq queues under this group, don't delete it */ 894 /* If there are other cfq queues under this group, don't delete it */
893 if (cfqg->nr_cfqq) 895 if (cfqg->nr_cfqq)
894 return; 896 return;
895 897
896 cfq_log_cfqg(cfqd, cfqg, "del_from_rr group"); 898 cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
897 cfqg->on_st = false; 899 cfqg->on_st = false;
898 st->total_weight -= cfqg->weight; 900 st->total_weight -= cfqg->weight;
899 if (!RB_EMPTY_NODE(&cfqg->rb_node)) 901 if (!RB_EMPTY_NODE(&cfqg->rb_node))
900 cfq_rb_erase(&cfqg->rb_node, st); 902 cfq_rb_erase(&cfqg->rb_node, st);
901 cfqg->saved_workload_slice = 0; 903 cfqg->saved_workload_slice = 0;
902 cfq_blkiocg_update_dequeue_stats(&cfqg->blkg, 1); 904 cfq_blkiocg_update_dequeue_stats(&cfqg->blkg, 1);
903 } 905 }
904 906
905 static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) 907 static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq)
906 { 908 {
907 unsigned int slice_used; 909 unsigned int slice_used;
908 910
909 /* 911 /*
910 * Queue got expired before even a single request completed or 912 * Queue got expired before even a single request completed or
911 * got expired immediately after first request completion. 913 * got expired immediately after first request completion.
912 */ 914 */
913 if (!cfqq->slice_start || cfqq->slice_start == jiffies) { 915 if (!cfqq->slice_start || cfqq->slice_start == jiffies) {
914 /* 916 /*
915 * Also charge the seek time incurred to the group, otherwise 917 * Also charge the seek time incurred to the group, otherwise
916 * if there are mutiple queues in the group, each can dispatch 918 * if there are mutiple queues in the group, each can dispatch
917 * a single request on seeky media and cause lots of seek time 919 * a single request on seeky media and cause lots of seek time
918 * and group will never know it. 920 * and group will never know it.
919 */ 921 */
920 slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), 922 slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start),
921 1); 923 1);
922 } else { 924 } else {
923 slice_used = jiffies - cfqq->slice_start; 925 slice_used = jiffies - cfqq->slice_start;
924 if (slice_used > cfqq->allocated_slice) 926 if (slice_used > cfqq->allocated_slice)
925 slice_used = cfqq->allocated_slice; 927 slice_used = cfqq->allocated_slice;
926 } 928 }
927 929
928 return slice_used; 930 return slice_used;
929 } 931 }
930 932
931 static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, 933 static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
932 struct cfq_queue *cfqq) 934 struct cfq_queue *cfqq)
933 { 935 {
934 struct cfq_rb_root *st = &cfqd->grp_service_tree; 936 struct cfq_rb_root *st = &cfqd->grp_service_tree;
935 unsigned int used_sl, charge; 937 unsigned int used_sl, charge;
936 int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) 938 int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg)
937 - cfqg->service_tree_idle.count; 939 - cfqg->service_tree_idle.count;
938 940
939 BUG_ON(nr_sync < 0); 941 BUG_ON(nr_sync < 0);
940 used_sl = charge = cfq_cfqq_slice_usage(cfqq); 942 used_sl = charge = cfq_cfqq_slice_usage(cfqq);
941 943
942 if (iops_mode(cfqd)) 944 if (iops_mode(cfqd))
943 charge = cfqq->slice_dispatch; 945 charge = cfqq->slice_dispatch;
944 else if (!cfq_cfqq_sync(cfqq) && !nr_sync) 946 else if (!cfq_cfqq_sync(cfqq) && !nr_sync)
945 charge = cfqq->allocated_slice; 947 charge = cfqq->allocated_slice;
946 948
947 /* Can't update vdisktime while group is on service tree */ 949 /* Can't update vdisktime while group is on service tree */
948 cfq_rb_erase(&cfqg->rb_node, st); 950 cfq_rb_erase(&cfqg->rb_node, st);
949 cfqg->vdisktime += cfq_scale_slice(charge, cfqg); 951 cfqg->vdisktime += cfq_scale_slice(charge, cfqg);
950 __cfq_group_service_tree_add(st, cfqg); 952 __cfq_group_service_tree_add(st, cfqg);
951 953
952 /* This group is being expired. Save the context */ 954 /* This group is being expired. Save the context */
953 if (time_after(cfqd->workload_expires, jiffies)) { 955 if (time_after(cfqd->workload_expires, jiffies)) {
954 cfqg->saved_workload_slice = cfqd->workload_expires 956 cfqg->saved_workload_slice = cfqd->workload_expires
955 - jiffies; 957 - jiffies;
956 cfqg->saved_workload = cfqd->serving_type; 958 cfqg->saved_workload = cfqd->serving_type;
957 cfqg->saved_serving_prio = cfqd->serving_prio; 959 cfqg->saved_serving_prio = cfqd->serving_prio;
958 } else 960 } else
959 cfqg->saved_workload_slice = 0; 961 cfqg->saved_workload_slice = 0;
960 962
961 cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, 963 cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
962 st->min_vdisktime); 964 st->min_vdisktime);
963 cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u disp=%u charge=%u iops=%u", 965 cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u disp=%u charge=%u iops=%u"
964 used_sl, cfqq->slice_dispatch, charge, iops_mode(cfqd)); 966 " sect=%u", used_sl, cfqq->slice_dispatch, charge,
967 iops_mode(cfqd), cfqq->nr_sectors);
965 cfq_blkiocg_update_timeslice_used(&cfqg->blkg, used_sl); 968 cfq_blkiocg_update_timeslice_used(&cfqg->blkg, used_sl);
966 cfq_blkiocg_set_start_empty_time(&cfqg->blkg); 969 cfq_blkiocg_set_start_empty_time(&cfqg->blkg);
967 } 970 }
968 971
969 #ifdef CONFIG_CFQ_GROUP_IOSCHED 972 #ifdef CONFIG_CFQ_GROUP_IOSCHED
970 static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg) 973 static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg)
971 { 974 {
972 if (blkg) 975 if (blkg)
973 return container_of(blkg, struct cfq_group, blkg); 976 return container_of(blkg, struct cfq_group, blkg);
974 return NULL; 977 return NULL;
975 } 978 }
976 979
977 void 980 void
978 cfq_update_blkio_group_weight(struct blkio_group *blkg, unsigned int weight) 981 cfq_update_blkio_group_weight(struct blkio_group *blkg, unsigned int weight)
979 { 982 {
980 cfqg_of_blkg(blkg)->weight = weight; 983 cfqg_of_blkg(blkg)->weight = weight;
981 } 984 }
982 985
983 static struct cfq_group * 986 static struct cfq_group *
984 cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create) 987 cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
985 { 988 {
986 struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); 989 struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
987 struct cfq_group *cfqg = NULL; 990 struct cfq_group *cfqg = NULL;
988 void *key = cfqd; 991 void *key = cfqd;
989 int i, j; 992 int i, j;
990 struct cfq_rb_root *st; 993 struct cfq_rb_root *st;
991 struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info; 994 struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info;
992 unsigned int major, minor; 995 unsigned int major, minor;
993 996
994 cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key)); 997 cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
995 if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) { 998 if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
996 sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); 999 sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
997 cfqg->blkg.dev = MKDEV(major, minor); 1000 cfqg->blkg.dev = MKDEV(major, minor);
998 goto done; 1001 goto done;
999 } 1002 }
1000 if (cfqg || !create) 1003 if (cfqg || !create)
1001 goto done; 1004 goto done;
1002 1005
1003 cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node); 1006 cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node);
1004 if (!cfqg) 1007 if (!cfqg)
1005 goto done; 1008 goto done;
1006 1009
1007 for_each_cfqg_st(cfqg, i, j, st) 1010 for_each_cfqg_st(cfqg, i, j, st)
1008 *st = CFQ_RB_ROOT; 1011 *st = CFQ_RB_ROOT;
1009 RB_CLEAR_NODE(&cfqg->rb_node); 1012 RB_CLEAR_NODE(&cfqg->rb_node);
1010 1013
1011 /* 1014 /*
1012 * Take the initial reference that will be released on destroy 1015 * Take the initial reference that will be released on destroy
1013 * This can be thought of a joint reference by cgroup and 1016 * This can be thought of a joint reference by cgroup and
1014 * elevator which will be dropped by either elevator exit 1017 * elevator which will be dropped by either elevator exit
1015 * or cgroup deletion path depending on who is exiting first. 1018 * or cgroup deletion path depending on who is exiting first.
1016 */ 1019 */
1017 atomic_set(&cfqg->ref, 1); 1020 atomic_set(&cfqg->ref, 1);
1018 1021
1019 /* Add group onto cgroup list */ 1022 /* Add group onto cgroup list */
1020 sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); 1023 sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
1021 cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd, 1024 cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
1022 MKDEV(major, minor)); 1025 MKDEV(major, minor));
1023 cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev); 1026 cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev);
1024 1027
1025 /* Add group on cfqd list */ 1028 /* Add group on cfqd list */
1026 hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list); 1029 hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
1027 1030
1028 done: 1031 done:
1029 return cfqg; 1032 return cfqg;
1030 } 1033 }
1031 1034
1032 /* 1035 /*
1033 * Search for the cfq group current task belongs to. If create = 1, then also 1036 * Search for the cfq group current task belongs to. If create = 1, then also
1034 * create the cfq group if it does not exist. request_queue lock must be held. 1037 * create the cfq group if it does not exist. request_queue lock must be held.
1035 */ 1038 */
1036 static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create) 1039 static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
1037 { 1040 {
1038 struct cgroup *cgroup; 1041 struct cgroup *cgroup;
1039 struct cfq_group *cfqg = NULL; 1042 struct cfq_group *cfqg = NULL;
1040 1043
1041 rcu_read_lock(); 1044 rcu_read_lock();
1042 cgroup = task_cgroup(current, blkio_subsys_id); 1045 cgroup = task_cgroup(current, blkio_subsys_id);
1043 cfqg = cfq_find_alloc_cfqg(cfqd, cgroup, create); 1046 cfqg = cfq_find_alloc_cfqg(cfqd, cgroup, create);
1044 if (!cfqg && create) 1047 if (!cfqg && create)
1045 cfqg = &cfqd->root_group; 1048 cfqg = &cfqd->root_group;
1046 rcu_read_unlock(); 1049 rcu_read_unlock();
1047 return cfqg; 1050 return cfqg;
1048 } 1051 }
1049 1052
1050 static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg) 1053 static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg)
1051 { 1054 {
1052 atomic_inc(&cfqg->ref); 1055 atomic_inc(&cfqg->ref);
1053 return cfqg; 1056 return cfqg;
1054 } 1057 }
1055 1058
1056 static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) 1059 static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg)
1057 { 1060 {
1058 /* Currently, all async queues are mapped to root group */ 1061 /* Currently, all async queues are mapped to root group */
1059 if (!cfq_cfqq_sync(cfqq)) 1062 if (!cfq_cfqq_sync(cfqq))
1060 cfqg = &cfqq->cfqd->root_group; 1063 cfqg = &cfqq->cfqd->root_group;
1061 1064
1062 cfqq->cfqg = cfqg; 1065 cfqq->cfqg = cfqg;
1063 /* cfqq reference on cfqg */ 1066 /* cfqq reference on cfqg */
1064 atomic_inc(&cfqq->cfqg->ref); 1067 atomic_inc(&cfqq->cfqg->ref);
1065 } 1068 }
1066 1069
1067 static void cfq_put_cfqg(struct cfq_group *cfqg) 1070 static void cfq_put_cfqg(struct cfq_group *cfqg)
1068 { 1071 {
1069 struct cfq_rb_root *st; 1072 struct cfq_rb_root *st;
1070 int i, j; 1073 int i, j;
1071 1074
1072 BUG_ON(atomic_read(&cfqg->ref) <= 0); 1075 BUG_ON(atomic_read(&cfqg->ref) <= 0);
1073 if (!atomic_dec_and_test(&cfqg->ref)) 1076 if (!atomic_dec_and_test(&cfqg->ref))
1074 return; 1077 return;
1075 for_each_cfqg_st(cfqg, i, j, st) 1078 for_each_cfqg_st(cfqg, i, j, st)
1076 BUG_ON(!RB_EMPTY_ROOT(&st->rb) || st->active != NULL); 1079 BUG_ON(!RB_EMPTY_ROOT(&st->rb) || st->active != NULL);
1077 kfree(cfqg); 1080 kfree(cfqg);
1078 } 1081 }
1079 1082
1080 static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg) 1083 static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg)
1081 { 1084 {
1082 /* Something wrong if we are trying to remove same group twice */ 1085 /* Something wrong if we are trying to remove same group twice */
1083 BUG_ON(hlist_unhashed(&cfqg->cfqd_node)); 1086 BUG_ON(hlist_unhashed(&cfqg->cfqd_node));
1084 1087
1085 hlist_del_init(&cfqg->cfqd_node); 1088 hlist_del_init(&cfqg->cfqd_node);
1086 1089
1087 /* 1090 /*
1088 * Put the reference taken at the time of creation so that when all 1091 * Put the reference taken at the time of creation so that when all
1089 * queues are gone, group can be destroyed. 1092 * queues are gone, group can be destroyed.
1090 */ 1093 */
1091 cfq_put_cfqg(cfqg); 1094 cfq_put_cfqg(cfqg);
1092 } 1095 }
1093 1096
1094 static void cfq_release_cfq_groups(struct cfq_data *cfqd) 1097 static void cfq_release_cfq_groups(struct cfq_data *cfqd)
1095 { 1098 {
1096 struct hlist_node *pos, *n; 1099 struct hlist_node *pos, *n;
1097 struct cfq_group *cfqg; 1100 struct cfq_group *cfqg;
1098 1101
1099 hlist_for_each_entry_safe(cfqg, pos, n, &cfqd->cfqg_list, cfqd_node) { 1102 hlist_for_each_entry_safe(cfqg, pos, n, &cfqd->cfqg_list, cfqd_node) {
1100 /* 1103 /*
1101 * If cgroup removal path got to blk_group first and removed 1104 * If cgroup removal path got to blk_group first and removed
1102 * it from cgroup list, then it will take care of destroying 1105 * it from cgroup list, then it will take care of destroying
1103 * cfqg also. 1106 * cfqg also.
1104 */ 1107 */
1105 if (!cfq_blkiocg_del_blkio_group(&cfqg->blkg)) 1108 if (!cfq_blkiocg_del_blkio_group(&cfqg->blkg))
1106 cfq_destroy_cfqg(cfqd, cfqg); 1109 cfq_destroy_cfqg(cfqd, cfqg);
1107 } 1110 }
1108 } 1111 }
1109 1112
1110 /* 1113 /*
1111 * Blk cgroup controller notification saying that blkio_group object is being 1114 * Blk cgroup controller notification saying that blkio_group object is being
1112 * delinked as associated cgroup object is going away. That also means that 1115 * delinked as associated cgroup object is going away. That also means that
1113 * no new IO will come in this group. So get rid of this group as soon as 1116 * no new IO will come in this group. So get rid of this group as soon as
1114 * any pending IO in the group is finished. 1117 * any pending IO in the group is finished.
1115 * 1118 *
1116 * This function is called under rcu_read_lock(). key is the rcu protected 1119 * This function is called under rcu_read_lock(). key is the rcu protected
1117 * pointer. That means "key" is a valid cfq_data pointer as long as we are rcu 1120 * pointer. That means "key" is a valid cfq_data pointer as long as we are rcu
1118 * read lock. 1121 * read lock.
1119 * 1122 *
1120 * "key" was fetched from blkio_group under blkio_cgroup->lock. That means 1123 * "key" was fetched from blkio_group under blkio_cgroup->lock. That means
1121 * it should not be NULL as even if elevator was exiting, cgroup deltion 1124 * it should not be NULL as even if elevator was exiting, cgroup deltion
1122 * path got to it first. 1125 * path got to it first.
1123 */ 1126 */
1124 void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg) 1127 void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg)
1125 { 1128 {
1126 unsigned long flags; 1129 unsigned long flags;
1127 struct cfq_data *cfqd = key; 1130 struct cfq_data *cfqd = key;
1128 1131
1129 spin_lock_irqsave(cfqd->queue->queue_lock, flags); 1132 spin_lock_irqsave(cfqd->queue->queue_lock, flags);
1130 cfq_destroy_cfqg(cfqd, cfqg_of_blkg(blkg)); 1133 cfq_destroy_cfqg(cfqd, cfqg_of_blkg(blkg));
1131 spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); 1134 spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
1132 } 1135 }
1133 1136
1134 #else /* GROUP_IOSCHED */ 1137 #else /* GROUP_IOSCHED */
1135 static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create) 1138 static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
1136 { 1139 {
1137 return &cfqd->root_group; 1140 return &cfqd->root_group;
1138 } 1141 }
1139 1142
1140 static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg) 1143 static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg)
1141 { 1144 {
1142 return cfqg; 1145 return cfqg;
1143 } 1146 }
1144 1147
1145 static inline void 1148 static inline void
1146 cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { 1149 cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) {
1147 cfqq->cfqg = cfqg; 1150 cfqq->cfqg = cfqg;
1148 } 1151 }
1149 1152
1150 static void cfq_release_cfq_groups(struct cfq_data *cfqd) {} 1153 static void cfq_release_cfq_groups(struct cfq_data *cfqd) {}
1151 static inline void cfq_put_cfqg(struct cfq_group *cfqg) {} 1154 static inline void cfq_put_cfqg(struct cfq_group *cfqg) {}
1152 1155
1153 #endif /* GROUP_IOSCHED */ 1156 #endif /* GROUP_IOSCHED */
1154 1157
1155 /* 1158 /*
1156 * The cfqd->service_trees holds all pending cfq_queue's that have 1159 * The cfqd->service_trees holds all pending cfq_queue's that have
1157 * requests waiting to be processed. It is sorted in the order that 1160 * requests waiting to be processed. It is sorted in the order that
1158 * we will service the queues. 1161 * we will service the queues.
1159 */ 1162 */
1160 static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, 1163 static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
1161 bool add_front) 1164 bool add_front)
1162 { 1165 {
1163 struct rb_node **p, *parent; 1166 struct rb_node **p, *parent;
1164 struct cfq_queue *__cfqq; 1167 struct cfq_queue *__cfqq;
1165 unsigned long rb_key; 1168 unsigned long rb_key;
1166 struct cfq_rb_root *service_tree; 1169 struct cfq_rb_root *service_tree;
1167 int left; 1170 int left;
1168 int new_cfqq = 1; 1171 int new_cfqq = 1;
1169 int group_changed = 0; 1172 int group_changed = 0;
1170 1173
1171 #ifdef CONFIG_CFQ_GROUP_IOSCHED 1174 #ifdef CONFIG_CFQ_GROUP_IOSCHED
1172 if (!cfqd->cfq_group_isolation 1175 if (!cfqd->cfq_group_isolation
1173 && cfqq_type(cfqq) == SYNC_NOIDLE_WORKLOAD 1176 && cfqq_type(cfqq) == SYNC_NOIDLE_WORKLOAD
1174 && cfqq->cfqg && cfqq->cfqg != &cfqd->root_group) { 1177 && cfqq->cfqg && cfqq->cfqg != &cfqd->root_group) {
1175 /* Move this cfq to root group */ 1178 /* Move this cfq to root group */
1176 cfq_log_cfqq(cfqd, cfqq, "moving to root group"); 1179 cfq_log_cfqq(cfqd, cfqq, "moving to root group");
1177 if (!RB_EMPTY_NODE(&cfqq->rb_node)) 1180 if (!RB_EMPTY_NODE(&cfqq->rb_node))
1178 cfq_group_service_tree_del(cfqd, cfqq->cfqg); 1181 cfq_group_service_tree_del(cfqd, cfqq->cfqg);
1179 cfqq->orig_cfqg = cfqq->cfqg; 1182 cfqq->orig_cfqg = cfqq->cfqg;
1180 cfqq->cfqg = &cfqd->root_group; 1183 cfqq->cfqg = &cfqd->root_group;
1181 atomic_inc(&cfqd->root_group.ref); 1184 atomic_inc(&cfqd->root_group.ref);
1182 group_changed = 1; 1185 group_changed = 1;
1183 } else if (!cfqd->cfq_group_isolation 1186 } else if (!cfqd->cfq_group_isolation
1184 && cfqq_type(cfqq) == SYNC_WORKLOAD && cfqq->orig_cfqg) { 1187 && cfqq_type(cfqq) == SYNC_WORKLOAD && cfqq->orig_cfqg) {
1185 /* cfqq is sequential now needs to go to its original group */ 1188 /* cfqq is sequential now needs to go to its original group */
1186 BUG_ON(cfqq->cfqg != &cfqd->root_group); 1189 BUG_ON(cfqq->cfqg != &cfqd->root_group);
1187 if (!RB_EMPTY_NODE(&cfqq->rb_node)) 1190 if (!RB_EMPTY_NODE(&cfqq->rb_node))
1188 cfq_group_service_tree_del(cfqd, cfqq->cfqg); 1191 cfq_group_service_tree_del(cfqd, cfqq->cfqg);
1189 cfq_put_cfqg(cfqq->cfqg); 1192 cfq_put_cfqg(cfqq->cfqg);
1190 cfqq->cfqg = cfqq->orig_cfqg; 1193 cfqq->cfqg = cfqq->orig_cfqg;
1191 cfqq->orig_cfqg = NULL; 1194 cfqq->orig_cfqg = NULL;
1192 group_changed = 1; 1195 group_changed = 1;
1193 cfq_log_cfqq(cfqd, cfqq, "moved to origin group"); 1196 cfq_log_cfqq(cfqd, cfqq, "moved to origin group");
1194 } 1197 }
1195 #endif 1198 #endif
1196 1199
1197 service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq), 1200 service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq),
1198 cfqq_type(cfqq)); 1201 cfqq_type(cfqq));
1199 if (cfq_class_idle(cfqq)) { 1202 if (cfq_class_idle(cfqq)) {
1200 rb_key = CFQ_IDLE_DELAY; 1203 rb_key = CFQ_IDLE_DELAY;
1201 parent = rb_last(&service_tree->rb); 1204 parent = rb_last(&service_tree->rb);
1202 if (parent && parent != &cfqq->rb_node) { 1205 if (parent && parent != &cfqq->rb_node) {
1203 __cfqq = rb_entry(parent, struct cfq_queue, rb_node); 1206 __cfqq = rb_entry(parent, struct cfq_queue, rb_node);
1204 rb_key += __cfqq->rb_key; 1207 rb_key += __cfqq->rb_key;
1205 } else 1208 } else
1206 rb_key += jiffies; 1209 rb_key += jiffies;
1207 } else if (!add_front) { 1210 } else if (!add_front) {
1208 /* 1211 /*
1209 * Get our rb key offset. Subtract any residual slice 1212 * Get our rb key offset. Subtract any residual slice
1210 * value carried from last service. A negative resid 1213 * value carried from last service. A negative resid
1211 * count indicates slice overrun, and this should position 1214 * count indicates slice overrun, and this should position
1212 * the next service time further away in the tree. 1215 * the next service time further away in the tree.
1213 */ 1216 */
1214 rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; 1217 rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies;
1215 rb_key -= cfqq->slice_resid; 1218 rb_key -= cfqq->slice_resid;
1216 cfqq->slice_resid = 0; 1219 cfqq->slice_resid = 0;
1217 } else { 1220 } else {
1218 rb_key = -HZ; 1221 rb_key = -HZ;
1219 __cfqq = cfq_rb_first(service_tree); 1222 __cfqq = cfq_rb_first(service_tree);
1220 rb_key += __cfqq ? __cfqq->rb_key : jiffies; 1223 rb_key += __cfqq ? __cfqq->rb_key : jiffies;
1221 } 1224 }
1222 1225
1223 if (!RB_EMPTY_NODE(&cfqq->rb_node)) { 1226 if (!RB_EMPTY_NODE(&cfqq->rb_node)) {
1224 new_cfqq = 0; 1227 new_cfqq = 0;
1225 /* 1228 /*
1226 * same position, nothing more to do 1229 * same position, nothing more to do
1227 */ 1230 */
1228 if (rb_key == cfqq->rb_key && 1231 if (rb_key == cfqq->rb_key &&
1229 cfqq->service_tree == service_tree) 1232 cfqq->service_tree == service_tree)
1230 return; 1233 return;
1231 1234
1232 cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); 1235 cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree);
1233 cfqq->service_tree = NULL; 1236 cfqq->service_tree = NULL;
1234 } 1237 }
1235 1238
1236 left = 1; 1239 left = 1;
1237 parent = NULL; 1240 parent = NULL;
1238 cfqq->service_tree = service_tree; 1241 cfqq->service_tree = service_tree;
1239 p = &service_tree->rb.rb_node; 1242 p = &service_tree->rb.rb_node;
1240 while (*p) { 1243 while (*p) {
1241 struct rb_node **n; 1244 struct rb_node **n;
1242 1245
1243 parent = *p; 1246 parent = *p;
1244 __cfqq = rb_entry(parent, struct cfq_queue, rb_node); 1247 __cfqq = rb_entry(parent, struct cfq_queue, rb_node);
1245 1248
1246 /* 1249 /*
1247 * sort by key, that represents service time. 1250 * sort by key, that represents service time.
1248 */ 1251 */
1249 if (time_before(rb_key, __cfqq->rb_key)) 1252 if (time_before(rb_key, __cfqq->rb_key))
1250 n = &(*p)->rb_left; 1253 n = &(*p)->rb_left;
1251 else { 1254 else {
1252 n = &(*p)->rb_right; 1255 n = &(*p)->rb_right;
1253 left = 0; 1256 left = 0;
1254 } 1257 }
1255 1258
1256 p = n; 1259 p = n;
1257 } 1260 }
1258 1261
1259 if (left) 1262 if (left)
1260 service_tree->left = &cfqq->rb_node; 1263 service_tree->left = &cfqq->rb_node;
1261 1264
1262 cfqq->rb_key = rb_key; 1265 cfqq->rb_key = rb_key;
1263 rb_link_node(&cfqq->rb_node, parent, p); 1266 rb_link_node(&cfqq->rb_node, parent, p);
1264 rb_insert_color(&cfqq->rb_node, &service_tree->rb); 1267 rb_insert_color(&cfqq->rb_node, &service_tree->rb);
1265 service_tree->count++; 1268 service_tree->count++;
1266 if ((add_front || !new_cfqq) && !group_changed) 1269 if ((add_front || !new_cfqq) && !group_changed)
1267 return; 1270 return;
1268 cfq_group_service_tree_add(cfqd, cfqq->cfqg); 1271 cfq_group_service_tree_add(cfqd, cfqq->cfqg);
1269 } 1272 }
1270 1273
1271 static struct cfq_queue * 1274 static struct cfq_queue *
1272 cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, 1275 cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root,
1273 sector_t sector, struct rb_node **ret_parent, 1276 sector_t sector, struct rb_node **ret_parent,
1274 struct rb_node ***rb_link) 1277 struct rb_node ***rb_link)
1275 { 1278 {
1276 struct rb_node **p, *parent; 1279 struct rb_node **p, *parent;
1277 struct cfq_queue *cfqq = NULL; 1280 struct cfq_queue *cfqq = NULL;
1278 1281
1279 parent = NULL; 1282 parent = NULL;
1280 p = &root->rb_node; 1283 p = &root->rb_node;
1281 while (*p) { 1284 while (*p) {
1282 struct rb_node **n; 1285 struct rb_node **n;
1283 1286
1284 parent = *p; 1287 parent = *p;
1285 cfqq = rb_entry(parent, struct cfq_queue, p_node); 1288 cfqq = rb_entry(parent, struct cfq_queue, p_node);
1286 1289
1287 /* 1290 /*
1288 * Sort strictly based on sector. Smallest to the left, 1291 * Sort strictly based on sector. Smallest to the left,
1289 * largest to the right. 1292 * largest to the right.
1290 */ 1293 */
1291 if (sector > blk_rq_pos(cfqq->next_rq)) 1294 if (sector > blk_rq_pos(cfqq->next_rq))
1292 n = &(*p)->rb_right; 1295 n = &(*p)->rb_right;
1293 else if (sector < blk_rq_pos(cfqq->next_rq)) 1296 else if (sector < blk_rq_pos(cfqq->next_rq))
1294 n = &(*p)->rb_left; 1297 n = &(*p)->rb_left;
1295 else 1298 else
1296 break; 1299 break;
1297 p = n; 1300 p = n;
1298 cfqq = NULL; 1301 cfqq = NULL;
1299 } 1302 }
1300 1303
1301 *ret_parent = parent; 1304 *ret_parent = parent;
1302 if (rb_link) 1305 if (rb_link)
1303 *rb_link = p; 1306 *rb_link = p;
1304 return cfqq; 1307 return cfqq;
1305 } 1308 }
1306 1309
1307 static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) 1310 static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq)
1308 { 1311 {
1309 struct rb_node **p, *parent; 1312 struct rb_node **p, *parent;
1310 struct cfq_queue *__cfqq; 1313 struct cfq_queue *__cfqq;
1311 1314
1312 if (cfqq->p_root) { 1315 if (cfqq->p_root) {
1313 rb_erase(&cfqq->p_node, cfqq->p_root); 1316 rb_erase(&cfqq->p_node, cfqq->p_root);
1314 cfqq->p_root = NULL; 1317 cfqq->p_root = NULL;
1315 } 1318 }
1316 1319
1317 if (cfq_class_idle(cfqq)) 1320 if (cfq_class_idle(cfqq))
1318 return; 1321 return;
1319 if (!cfqq->next_rq) 1322 if (!cfqq->next_rq)
1320 return; 1323 return;
1321 1324
1322 cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; 1325 cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio];
1323 __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, 1326 __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root,
1324 blk_rq_pos(cfqq->next_rq), &parent, &p); 1327 blk_rq_pos(cfqq->next_rq), &parent, &p);
1325 if (!__cfqq) { 1328 if (!__cfqq) {
1326 rb_link_node(&cfqq->p_node, parent, p); 1329 rb_link_node(&cfqq->p_node, parent, p);
1327 rb_insert_color(&cfqq->p_node, cfqq->p_root); 1330 rb_insert_color(&cfqq->p_node, cfqq->p_root);
1328 } else 1331 } else
1329 cfqq->p_root = NULL; 1332 cfqq->p_root = NULL;
1330 } 1333 }
1331 1334
1332 /* 1335 /*
1333 * Update cfqq's position in the service tree. 1336 * Update cfqq's position in the service tree.
1334 */ 1337 */
1335 static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) 1338 static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq)
1336 { 1339 {
1337 /* 1340 /*
1338 * Resorting requires the cfqq to be on the RR list already. 1341 * Resorting requires the cfqq to be on the RR list already.
1339 */ 1342 */
1340 if (cfq_cfqq_on_rr(cfqq)) { 1343 if (cfq_cfqq_on_rr(cfqq)) {
1341 cfq_service_tree_add(cfqd, cfqq, 0); 1344 cfq_service_tree_add(cfqd, cfqq, 0);
1342 cfq_prio_tree_add(cfqd, cfqq); 1345 cfq_prio_tree_add(cfqd, cfqq);
1343 } 1346 }
1344 } 1347 }
1345 1348
1346 /* 1349 /*
1347 * add to busy list of queues for service, trying to be fair in ordering 1350 * add to busy list of queues for service, trying to be fair in ordering
1348 * the pending list according to last request service 1351 * the pending list according to last request service
1349 */ 1352 */
1350 static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) 1353 static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
1351 { 1354 {
1352 cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); 1355 cfq_log_cfqq(cfqd, cfqq, "add_to_rr");
1353 BUG_ON(cfq_cfqq_on_rr(cfqq)); 1356 BUG_ON(cfq_cfqq_on_rr(cfqq));
1354 cfq_mark_cfqq_on_rr(cfqq); 1357 cfq_mark_cfqq_on_rr(cfqq);
1355 cfqd->busy_queues++; 1358 cfqd->busy_queues++;
1356 1359
1357 cfq_resort_rr_list(cfqd, cfqq); 1360 cfq_resort_rr_list(cfqd, cfqq);
1358 } 1361 }
1359 1362
1360 /* 1363 /*
1361 * Called when the cfqq no longer has requests pending, remove it from 1364 * Called when the cfqq no longer has requests pending, remove it from
1362 * the service tree. 1365 * the service tree.
1363 */ 1366 */
1364 static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) 1367 static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
1365 { 1368 {
1366 cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); 1369 cfq_log_cfqq(cfqd, cfqq, "del_from_rr");
1367 BUG_ON(!cfq_cfqq_on_rr(cfqq)); 1370 BUG_ON(!cfq_cfqq_on_rr(cfqq));
1368 cfq_clear_cfqq_on_rr(cfqq); 1371 cfq_clear_cfqq_on_rr(cfqq);
1369 1372
1370 if (!RB_EMPTY_NODE(&cfqq->rb_node)) { 1373 if (!RB_EMPTY_NODE(&cfqq->rb_node)) {
1371 cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); 1374 cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree);
1372 cfqq->service_tree = NULL; 1375 cfqq->service_tree = NULL;
1373 } 1376 }
1374 if (cfqq->p_root) { 1377 if (cfqq->p_root) {
1375 rb_erase(&cfqq->p_node, cfqq->p_root); 1378 rb_erase(&cfqq->p_node, cfqq->p_root);
1376 cfqq->p_root = NULL; 1379 cfqq->p_root = NULL;
1377 } 1380 }
1378 1381
1379 cfq_group_service_tree_del(cfqd, cfqq->cfqg); 1382 cfq_group_service_tree_del(cfqd, cfqq->cfqg);
1380 BUG_ON(!cfqd->busy_queues); 1383 BUG_ON(!cfqd->busy_queues);
1381 cfqd->busy_queues--; 1384 cfqd->busy_queues--;
1382 } 1385 }
1383 1386
1384 /* 1387 /*
1385 * rb tree support functions 1388 * rb tree support functions
1386 */ 1389 */
1387 static void cfq_del_rq_rb(struct request *rq) 1390 static void cfq_del_rq_rb(struct request *rq)
1388 { 1391 {
1389 struct cfq_queue *cfqq = RQ_CFQQ(rq); 1392 struct cfq_queue *cfqq = RQ_CFQQ(rq);
1390 const int sync = rq_is_sync(rq); 1393 const int sync = rq_is_sync(rq);
1391 1394
1392 BUG_ON(!cfqq->queued[sync]); 1395 BUG_ON(!cfqq->queued[sync]);
1393 cfqq->queued[sync]--; 1396 cfqq->queued[sync]--;
1394 1397
1395 elv_rb_del(&cfqq->sort_list, rq); 1398 elv_rb_del(&cfqq->sort_list, rq);
1396 1399
1397 if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) { 1400 if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) {
1398 /* 1401 /*
1399 * Queue will be deleted from service tree when we actually 1402 * Queue will be deleted from service tree when we actually
1400 * expire it later. Right now just remove it from prio tree 1403 * expire it later. Right now just remove it from prio tree
1401 * as it is empty. 1404 * as it is empty.
1402 */ 1405 */
1403 if (cfqq->p_root) { 1406 if (cfqq->p_root) {
1404 rb_erase(&cfqq->p_node, cfqq->p_root); 1407 rb_erase(&cfqq->p_node, cfqq->p_root);
1405 cfqq->p_root = NULL; 1408 cfqq->p_root = NULL;
1406 } 1409 }
1407 } 1410 }
1408 } 1411 }
1409 1412
1410 static void cfq_add_rq_rb(struct request *rq) 1413 static void cfq_add_rq_rb(struct request *rq)
1411 { 1414 {
1412 struct cfq_queue *cfqq = RQ_CFQQ(rq); 1415 struct cfq_queue *cfqq = RQ_CFQQ(rq);
1413 struct cfq_data *cfqd = cfqq->cfqd; 1416 struct cfq_data *cfqd = cfqq->cfqd;
1414 struct request *__alias, *prev; 1417 struct request *__alias, *prev;
1415 1418
1416 cfqq->queued[rq_is_sync(rq)]++; 1419 cfqq->queued[rq_is_sync(rq)]++;
1417 1420
1418 /* 1421 /*
1419 * looks a little odd, but the first insert might return an alias. 1422 * looks a little odd, but the first insert might return an alias.
1420 * if that happens, put the alias on the dispatch list 1423 * if that happens, put the alias on the dispatch list
1421 */ 1424 */
1422 while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) 1425 while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL)
1423 cfq_dispatch_insert(cfqd->queue, __alias); 1426 cfq_dispatch_insert(cfqd->queue, __alias);
1424 1427
1425 if (!cfq_cfqq_on_rr(cfqq)) 1428 if (!cfq_cfqq_on_rr(cfqq))
1426 cfq_add_cfqq_rr(cfqd, cfqq); 1429 cfq_add_cfqq_rr(cfqd, cfqq);
1427 1430
1428 /* 1431 /*
1429 * check if this request is a better next-serve candidate 1432 * check if this request is a better next-serve candidate
1430 */ 1433 */
1431 prev = cfqq->next_rq; 1434 prev = cfqq->next_rq;
1432 cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position); 1435 cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position);
1433 1436
1434 /* 1437 /*
1435 * adjust priority tree position, if ->next_rq changes 1438 * adjust priority tree position, if ->next_rq changes
1436 */ 1439 */
1437 if (prev != cfqq->next_rq) 1440 if (prev != cfqq->next_rq)
1438 cfq_prio_tree_add(cfqd, cfqq); 1441 cfq_prio_tree_add(cfqd, cfqq);
1439 1442
1440 BUG_ON(!cfqq->next_rq); 1443 BUG_ON(!cfqq->next_rq);
1441 } 1444 }
1442 1445
1443 static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) 1446 static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
1444 { 1447 {
1445 elv_rb_del(&cfqq->sort_list, rq); 1448 elv_rb_del(&cfqq->sort_list, rq);
1446 cfqq->queued[rq_is_sync(rq)]--; 1449 cfqq->queued[rq_is_sync(rq)]--;
1447 cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, 1450 cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg,
1448 rq_data_dir(rq), rq_is_sync(rq)); 1451 rq_data_dir(rq), rq_is_sync(rq));
1449 cfq_add_rq_rb(rq); 1452 cfq_add_rq_rb(rq);
1450 cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg, 1453 cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
1451 &cfqq->cfqd->serving_group->blkg, rq_data_dir(rq), 1454 &cfqq->cfqd->serving_group->blkg, rq_data_dir(rq),
1452 rq_is_sync(rq)); 1455 rq_is_sync(rq));
1453 } 1456 }
1454 1457
1455 static struct request * 1458 static struct request *
1456 cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) 1459 cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
1457 { 1460 {
1458 struct task_struct *tsk = current; 1461 struct task_struct *tsk = current;
1459 struct cfq_io_context *cic; 1462 struct cfq_io_context *cic;
1460 struct cfq_queue *cfqq; 1463 struct cfq_queue *cfqq;
1461 1464
1462 cic = cfq_cic_lookup(cfqd, tsk->io_context); 1465 cic = cfq_cic_lookup(cfqd, tsk->io_context);
1463 if (!cic) 1466 if (!cic)
1464 return NULL; 1467 return NULL;
1465 1468
1466 cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); 1469 cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio));
1467 if (cfqq) { 1470 if (cfqq) {
1468 sector_t sector = bio->bi_sector + bio_sectors(bio); 1471 sector_t sector = bio->bi_sector + bio_sectors(bio);
1469 1472
1470 return elv_rb_find(&cfqq->sort_list, sector); 1473 return elv_rb_find(&cfqq->sort_list, sector);
1471 } 1474 }
1472 1475
1473 return NULL; 1476 return NULL;
1474 } 1477 }
1475 1478
1476 static void cfq_activate_request(struct request_queue *q, struct request *rq) 1479 static void cfq_activate_request(struct request_queue *q, struct request *rq)
1477 { 1480 {
1478 struct cfq_data *cfqd = q->elevator->elevator_data; 1481 struct cfq_data *cfqd = q->elevator->elevator_data;
1479 1482
1480 cfqd->rq_in_driver++; 1483 cfqd->rq_in_driver++;
1481 cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", 1484 cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d",
1482 cfqd->rq_in_driver); 1485 cfqd->rq_in_driver);
1483 1486
1484 cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); 1487 cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq);
1485 } 1488 }
1486 1489
1487 static void cfq_deactivate_request(struct request_queue *q, struct request *rq) 1490 static void cfq_deactivate_request(struct request_queue *q, struct request *rq)
1488 { 1491 {
1489 struct cfq_data *cfqd = q->elevator->elevator_data; 1492 struct cfq_data *cfqd = q->elevator->elevator_data;
1490 1493
1491 WARN_ON(!cfqd->rq_in_driver); 1494 WARN_ON(!cfqd->rq_in_driver);
1492 cfqd->rq_in_driver--; 1495 cfqd->rq_in_driver--;
1493 cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", 1496 cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d",
1494 cfqd->rq_in_driver); 1497 cfqd->rq_in_driver);
1495 } 1498 }
1496 1499
1497 static void cfq_remove_request(struct request *rq) 1500 static void cfq_remove_request(struct request *rq)
1498 { 1501 {
1499 struct cfq_queue *cfqq = RQ_CFQQ(rq); 1502 struct cfq_queue *cfqq = RQ_CFQQ(rq);
1500 1503
1501 if (cfqq->next_rq == rq) 1504 if (cfqq->next_rq == rq)
1502 cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); 1505 cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq);
1503 1506
1504 list_del_init(&rq->queuelist); 1507 list_del_init(&rq->queuelist);
1505 cfq_del_rq_rb(rq); 1508 cfq_del_rq_rb(rq);
1506 1509
1507 cfqq->cfqd->rq_queued--; 1510 cfqq->cfqd->rq_queued--;
1508 cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, 1511 cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg,
1509 rq_data_dir(rq), rq_is_sync(rq)); 1512 rq_data_dir(rq), rq_is_sync(rq));
1510 if (rq->cmd_flags & REQ_META) { 1513 if (rq->cmd_flags & REQ_META) {
1511 WARN_ON(!cfqq->meta_pending); 1514 WARN_ON(!cfqq->meta_pending);
1512 cfqq->meta_pending--; 1515 cfqq->meta_pending--;
1513 } 1516 }
1514 } 1517 }
1515 1518
1516 static int cfq_merge(struct request_queue *q, struct request **req, 1519 static int cfq_merge(struct request_queue *q, struct request **req,
1517 struct bio *bio) 1520 struct bio *bio)
1518 { 1521 {
1519 struct cfq_data *cfqd = q->elevator->elevator_data; 1522 struct cfq_data *cfqd = q->elevator->elevator_data;
1520 struct request *__rq; 1523 struct request *__rq;
1521 1524
1522 __rq = cfq_find_rq_fmerge(cfqd, bio); 1525 __rq = cfq_find_rq_fmerge(cfqd, bio);
1523 if (__rq && elv_rq_merge_ok(__rq, bio)) { 1526 if (__rq && elv_rq_merge_ok(__rq, bio)) {
1524 *req = __rq; 1527 *req = __rq;
1525 return ELEVATOR_FRONT_MERGE; 1528 return ELEVATOR_FRONT_MERGE;
1526 } 1529 }
1527 1530
1528 return ELEVATOR_NO_MERGE; 1531 return ELEVATOR_NO_MERGE;
1529 } 1532 }
1530 1533
1531 static void cfq_merged_request(struct request_queue *q, struct request *req, 1534 static void cfq_merged_request(struct request_queue *q, struct request *req,
1532 int type) 1535 int type)
1533 { 1536 {
1534 if (type == ELEVATOR_FRONT_MERGE) { 1537 if (type == ELEVATOR_FRONT_MERGE) {
1535 struct cfq_queue *cfqq = RQ_CFQQ(req); 1538 struct cfq_queue *cfqq = RQ_CFQQ(req);
1536 1539
1537 cfq_reposition_rq_rb(cfqq, req); 1540 cfq_reposition_rq_rb(cfqq, req);
1538 } 1541 }
1539 } 1542 }
1540 1543
1541 static void cfq_bio_merged(struct request_queue *q, struct request *req, 1544 static void cfq_bio_merged(struct request_queue *q, struct request *req,
1542 struct bio *bio) 1545 struct bio *bio)
1543 { 1546 {
1544 cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(req))->blkg, 1547 cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(req))->blkg,
1545 bio_data_dir(bio), cfq_bio_sync(bio)); 1548 bio_data_dir(bio), cfq_bio_sync(bio));
1546 } 1549 }
1547 1550
1548 static void 1551 static void
1549 cfq_merged_requests(struct request_queue *q, struct request *rq, 1552 cfq_merged_requests(struct request_queue *q, struct request *rq,
1550 struct request *next) 1553 struct request *next)
1551 { 1554 {
1552 struct cfq_queue *cfqq = RQ_CFQQ(rq); 1555 struct cfq_queue *cfqq = RQ_CFQQ(rq);
1553 /* 1556 /*
1554 * reposition in fifo if next is older than rq 1557 * reposition in fifo if next is older than rq
1555 */ 1558 */
1556 if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && 1559 if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) &&
1557 time_before(rq_fifo_time(next), rq_fifo_time(rq))) { 1560 time_before(rq_fifo_time(next), rq_fifo_time(rq))) {
1558 list_move(&rq->queuelist, &next->queuelist); 1561 list_move(&rq->queuelist, &next->queuelist);
1559 rq_set_fifo_time(rq, rq_fifo_time(next)); 1562 rq_set_fifo_time(rq, rq_fifo_time(next));
1560 } 1563 }
1561 1564
1562 if (cfqq->next_rq == next) 1565 if (cfqq->next_rq == next)
1563 cfqq->next_rq = rq; 1566 cfqq->next_rq = rq;
1564 cfq_remove_request(next); 1567 cfq_remove_request(next);
1565 cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(rq))->blkg, 1568 cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(rq))->blkg,
1566 rq_data_dir(next), rq_is_sync(next)); 1569 rq_data_dir(next), rq_is_sync(next));
1567 } 1570 }
1568 1571
1569 static int cfq_allow_merge(struct request_queue *q, struct request *rq, 1572 static int cfq_allow_merge(struct request_queue *q, struct request *rq,
1570 struct bio *bio) 1573 struct bio *bio)
1571 { 1574 {
1572 struct cfq_data *cfqd = q->elevator->elevator_data; 1575 struct cfq_data *cfqd = q->elevator->elevator_data;
1573 struct cfq_io_context *cic; 1576 struct cfq_io_context *cic;
1574 struct cfq_queue *cfqq; 1577 struct cfq_queue *cfqq;
1575 1578
1576 /* 1579 /*
1577 * Disallow merge of a sync bio into an async request. 1580 * Disallow merge of a sync bio into an async request.
1578 */ 1581 */
1579 if (cfq_bio_sync(bio) && !rq_is_sync(rq)) 1582 if (cfq_bio_sync(bio) && !rq_is_sync(rq))
1580 return false; 1583 return false;
1581 1584
1582 /* 1585 /*
1583 * Lookup the cfqq that this bio will be queued with. Allow 1586 * Lookup the cfqq that this bio will be queued with. Allow
1584 * merge only if rq is queued there. 1587 * merge only if rq is queued there.
1585 */ 1588 */
1586 cic = cfq_cic_lookup(cfqd, current->io_context); 1589 cic = cfq_cic_lookup(cfqd, current->io_context);
1587 if (!cic) 1590 if (!cic)
1588 return false; 1591 return false;
1589 1592
1590 cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); 1593 cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio));
1591 return cfqq == RQ_CFQQ(rq); 1594 return cfqq == RQ_CFQQ(rq);
1592 } 1595 }
1593 1596
1594 static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) 1597 static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
1595 { 1598 {
1596 del_timer(&cfqd->idle_slice_timer); 1599 del_timer(&cfqd->idle_slice_timer);
1597 cfq_blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg); 1600 cfq_blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg);
1598 } 1601 }
1599 1602
1600 static void __cfq_set_active_queue(struct cfq_data *cfqd, 1603 static void __cfq_set_active_queue(struct cfq_data *cfqd,
1601 struct cfq_queue *cfqq) 1604 struct cfq_queue *cfqq)
1602 { 1605 {
1603 if (cfqq) { 1606 if (cfqq) {
1604 cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d", 1607 cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d",
1605 cfqd->serving_prio, cfqd->serving_type); 1608 cfqd->serving_prio, cfqd->serving_type);
1606 cfq_blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg); 1609 cfq_blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg);
1607 cfqq->slice_start = 0; 1610 cfqq->slice_start = 0;
1608 cfqq->dispatch_start = jiffies; 1611 cfqq->dispatch_start = jiffies;
1609 cfqq->allocated_slice = 0; 1612 cfqq->allocated_slice = 0;
1610 cfqq->slice_end = 0; 1613 cfqq->slice_end = 0;
1611 cfqq->slice_dispatch = 0; 1614 cfqq->slice_dispatch = 0;
1615 cfqq->nr_sectors = 0;
1612 1616
1613 cfq_clear_cfqq_wait_request(cfqq); 1617 cfq_clear_cfqq_wait_request(cfqq);
1614 cfq_clear_cfqq_must_dispatch(cfqq); 1618 cfq_clear_cfqq_must_dispatch(cfqq);
1615 cfq_clear_cfqq_must_alloc_slice(cfqq); 1619 cfq_clear_cfqq_must_alloc_slice(cfqq);
1616 cfq_clear_cfqq_fifo_expire(cfqq); 1620 cfq_clear_cfqq_fifo_expire(cfqq);
1617 cfq_mark_cfqq_slice_new(cfqq); 1621 cfq_mark_cfqq_slice_new(cfqq);
1618 1622
1619 cfq_del_timer(cfqd, cfqq); 1623 cfq_del_timer(cfqd, cfqq);
1620 } 1624 }
1621 1625
1622 cfqd->active_queue = cfqq; 1626 cfqd->active_queue = cfqq;
1623 } 1627 }
1624 1628
1625 /* 1629 /*
1626 * current cfqq expired its slice (or was too idle), select new one 1630 * current cfqq expired its slice (or was too idle), select new one
1627 */ 1631 */
1628 static void 1632 static void
1629 __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, 1633 __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
1630 bool timed_out) 1634 bool timed_out)
1631 { 1635 {
1632 cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); 1636 cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out);
1633 1637
1634 if (cfq_cfqq_wait_request(cfqq)) 1638 if (cfq_cfqq_wait_request(cfqq))
1635 cfq_del_timer(cfqd, cfqq); 1639 cfq_del_timer(cfqd, cfqq);
1636 1640
1637 cfq_clear_cfqq_wait_request(cfqq); 1641 cfq_clear_cfqq_wait_request(cfqq);
1638 cfq_clear_cfqq_wait_busy(cfqq); 1642 cfq_clear_cfqq_wait_busy(cfqq);
1639 1643
1640 /* 1644 /*
1641 * If this cfqq is shared between multiple processes, check to 1645 * If this cfqq is shared between multiple processes, check to
1642 * make sure that those processes are still issuing I/Os within 1646 * make sure that those processes are still issuing I/Os within
1643 * the mean seek distance. If not, it may be time to break the 1647 * the mean seek distance. If not, it may be time to break the
1644 * queues apart again. 1648 * queues apart again.
1645 */ 1649 */
1646 if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq)) 1650 if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq))
1647 cfq_mark_cfqq_split_coop(cfqq); 1651 cfq_mark_cfqq_split_coop(cfqq);
1648 1652
1649 /* 1653 /*
1650 * store what was left of this slice, if the queue idled/timed out 1654 * store what was left of this slice, if the queue idled/timed out
1651 */ 1655 */
1652 if (timed_out && !cfq_cfqq_slice_new(cfqq)) { 1656 if (timed_out && !cfq_cfqq_slice_new(cfqq)) {
1653 cfqq->slice_resid = cfqq->slice_end - jiffies; 1657 cfqq->slice_resid = cfqq->slice_end - jiffies;
1654 cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); 1658 cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid);
1655 } 1659 }
1656 1660
1657 cfq_group_served(cfqd, cfqq->cfqg, cfqq); 1661 cfq_group_served(cfqd, cfqq->cfqg, cfqq);
1658 1662
1659 if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) 1663 if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
1660 cfq_del_cfqq_rr(cfqd, cfqq); 1664 cfq_del_cfqq_rr(cfqd, cfqq);
1661 1665
1662 cfq_resort_rr_list(cfqd, cfqq); 1666 cfq_resort_rr_list(cfqd, cfqq);
1663 1667
1664 if (cfqq == cfqd->active_queue) 1668 if (cfqq == cfqd->active_queue)
1665 cfqd->active_queue = NULL; 1669 cfqd->active_queue = NULL;
1666 1670
1667 if (&cfqq->cfqg->rb_node == cfqd->grp_service_tree.active) 1671 if (&cfqq->cfqg->rb_node == cfqd->grp_service_tree.active)
1668 cfqd->grp_service_tree.active = NULL; 1672 cfqd->grp_service_tree.active = NULL;
1669 1673
1670 if (cfqd->active_cic) { 1674 if (cfqd->active_cic) {
1671 put_io_context(cfqd->active_cic->ioc); 1675 put_io_context(cfqd->active_cic->ioc);
1672 cfqd->active_cic = NULL; 1676 cfqd->active_cic = NULL;
1673 } 1677 }
1674 } 1678 }
1675 1679
1676 static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) 1680 static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out)
1677 { 1681 {
1678 struct cfq_queue *cfqq = cfqd->active_queue; 1682 struct cfq_queue *cfqq = cfqd->active_queue;
1679 1683
1680 if (cfqq) 1684 if (cfqq)
1681 __cfq_slice_expired(cfqd, cfqq, timed_out); 1685 __cfq_slice_expired(cfqd, cfqq, timed_out);
1682 } 1686 }
1683 1687
1684 /* 1688 /*
1685 * Get next queue for service. Unless we have a queue preemption, 1689 * Get next queue for service. Unless we have a queue preemption,
1686 * we'll simply select the first cfqq in the service tree. 1690 * we'll simply select the first cfqq in the service tree.
1687 */ 1691 */
1688 static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) 1692 static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
1689 { 1693 {
1690 struct cfq_rb_root *service_tree = 1694 struct cfq_rb_root *service_tree =
1691 service_tree_for(cfqd->serving_group, cfqd->serving_prio, 1695 service_tree_for(cfqd->serving_group, cfqd->serving_prio,
1692 cfqd->serving_type); 1696 cfqd->serving_type);
1693 1697
1694 if (!cfqd->rq_queued) 1698 if (!cfqd->rq_queued)
1695 return NULL; 1699 return NULL;
1696 1700
1697 /* There is nothing to dispatch */ 1701 /* There is nothing to dispatch */
1698 if (!service_tree) 1702 if (!service_tree)
1699 return NULL; 1703 return NULL;
1700 if (RB_EMPTY_ROOT(&service_tree->rb)) 1704 if (RB_EMPTY_ROOT(&service_tree->rb))
1701 return NULL; 1705 return NULL;
1702 return cfq_rb_first(service_tree); 1706 return cfq_rb_first(service_tree);
1703 } 1707 }
1704 1708
1705 static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) 1709 static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
1706 { 1710 {
1707 struct cfq_group *cfqg; 1711 struct cfq_group *cfqg;
1708 struct cfq_queue *cfqq; 1712 struct cfq_queue *cfqq;
1709 int i, j; 1713 int i, j;
1710 struct cfq_rb_root *st; 1714 struct cfq_rb_root *st;
1711 1715
1712 if (!cfqd->rq_queued) 1716 if (!cfqd->rq_queued)
1713 return NULL; 1717 return NULL;
1714 1718
1715 cfqg = cfq_get_next_cfqg(cfqd); 1719 cfqg = cfq_get_next_cfqg(cfqd);
1716 if (!cfqg) 1720 if (!cfqg)
1717 return NULL; 1721 return NULL;
1718 1722
1719 for_each_cfqg_st(cfqg, i, j, st) 1723 for_each_cfqg_st(cfqg, i, j, st)
1720 if ((cfqq = cfq_rb_first(st)) != NULL) 1724 if ((cfqq = cfq_rb_first(st)) != NULL)
1721 return cfqq; 1725 return cfqq;
1722 return NULL; 1726 return NULL;
1723 } 1727 }
1724 1728
1725 /* 1729 /*
1726 * Get and set a new active queue for service. 1730 * Get and set a new active queue for service.
1727 */ 1731 */
1728 static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, 1732 static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd,
1729 struct cfq_queue *cfqq) 1733 struct cfq_queue *cfqq)
1730 { 1734 {
1731 if (!cfqq) 1735 if (!cfqq)
1732 cfqq = cfq_get_next_queue(cfqd); 1736 cfqq = cfq_get_next_queue(cfqd);
1733 1737
1734 __cfq_set_active_queue(cfqd, cfqq); 1738 __cfq_set_active_queue(cfqd, cfqq);
1735 return cfqq; 1739 return cfqq;
1736 } 1740 }
1737 1741
1738 static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, 1742 static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd,
1739 struct request *rq) 1743 struct request *rq)
1740 { 1744 {
1741 if (blk_rq_pos(rq) >= cfqd->last_position) 1745 if (blk_rq_pos(rq) >= cfqd->last_position)
1742 return blk_rq_pos(rq) - cfqd->last_position; 1746 return blk_rq_pos(rq) - cfqd->last_position;
1743 else 1747 else
1744 return cfqd->last_position - blk_rq_pos(rq); 1748 return cfqd->last_position - blk_rq_pos(rq);
1745 } 1749 }
1746 1750
1747 static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq, 1751 static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq,
1748 struct request *rq) 1752 struct request *rq)
1749 { 1753 {
1750 return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR; 1754 return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR;
1751 } 1755 }
1752 1756
1753 static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, 1757 static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
1754 struct cfq_queue *cur_cfqq) 1758 struct cfq_queue *cur_cfqq)
1755 { 1759 {
1756 struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; 1760 struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio];
1757 struct rb_node *parent, *node; 1761 struct rb_node *parent, *node;
1758 struct cfq_queue *__cfqq; 1762 struct cfq_queue *__cfqq;
1759 sector_t sector = cfqd->last_position; 1763 sector_t sector = cfqd->last_position;
1760 1764
1761 if (RB_EMPTY_ROOT(root)) 1765 if (RB_EMPTY_ROOT(root))
1762 return NULL; 1766 return NULL;
1763 1767
1764 /* 1768 /*
1765 * First, if we find a request starting at the end of the last 1769 * First, if we find a request starting at the end of the last
1766 * request, choose it. 1770 * request, choose it.
1767 */ 1771 */
1768 __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); 1772 __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL);
1769 if (__cfqq) 1773 if (__cfqq)
1770 return __cfqq; 1774 return __cfqq;
1771 1775
1772 /* 1776 /*
1773 * If the exact sector wasn't found, the parent of the NULL leaf 1777 * If the exact sector wasn't found, the parent of the NULL leaf
1774 * will contain the closest sector. 1778 * will contain the closest sector.
1775 */ 1779 */
1776 __cfqq = rb_entry(parent, struct cfq_queue, p_node); 1780 __cfqq = rb_entry(parent, struct cfq_queue, p_node);
1777 if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) 1781 if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
1778 return __cfqq; 1782 return __cfqq;
1779 1783
1780 if (blk_rq_pos(__cfqq->next_rq) < sector) 1784 if (blk_rq_pos(__cfqq->next_rq) < sector)
1781 node = rb_next(&__cfqq->p_node); 1785 node = rb_next(&__cfqq->p_node);
1782 else 1786 else
1783 node = rb_prev(&__cfqq->p_node); 1787 node = rb_prev(&__cfqq->p_node);
1784 if (!node) 1788 if (!node)
1785 return NULL; 1789 return NULL;
1786 1790
1787 __cfqq = rb_entry(node, struct cfq_queue, p_node); 1791 __cfqq = rb_entry(node, struct cfq_queue, p_node);
1788 if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) 1792 if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
1789 return __cfqq; 1793 return __cfqq;
1790 1794
1791 return NULL; 1795 return NULL;
1792 } 1796 }
1793 1797
1794 /* 1798 /*
1795 * cfqd - obvious 1799 * cfqd - obvious
1796 * cur_cfqq - passed in so that we don't decide that the current queue is 1800 * cur_cfqq - passed in so that we don't decide that the current queue is
1797 * closely cooperating with itself. 1801 * closely cooperating with itself.
1798 * 1802 *
1799 * So, basically we're assuming that that cur_cfqq has dispatched at least 1803 * So, basically we're assuming that that cur_cfqq has dispatched at least
1800 * one request, and that cfqd->last_position reflects a position on the disk 1804 * one request, and that cfqd->last_position reflects a position on the disk
1801 * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid 1805 * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid
1802 * assumption. 1806 * assumption.
1803 */ 1807 */
1804 static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, 1808 static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd,
1805 struct cfq_queue *cur_cfqq) 1809 struct cfq_queue *cur_cfqq)
1806 { 1810 {
1807 struct cfq_queue *cfqq; 1811 struct cfq_queue *cfqq;
1808 1812
1809 if (cfq_class_idle(cur_cfqq)) 1813 if (cfq_class_idle(cur_cfqq))
1810 return NULL; 1814 return NULL;
1811 if (!cfq_cfqq_sync(cur_cfqq)) 1815 if (!cfq_cfqq_sync(cur_cfqq))
1812 return NULL; 1816 return NULL;
1813 if (CFQQ_SEEKY(cur_cfqq)) 1817 if (CFQQ_SEEKY(cur_cfqq))
1814 return NULL; 1818 return NULL;
1815 1819
1816 /* 1820 /*
1817 * Don't search priority tree if it's the only queue in the group. 1821 * Don't search priority tree if it's the only queue in the group.
1818 */ 1822 */
1819 if (cur_cfqq->cfqg->nr_cfqq == 1) 1823 if (cur_cfqq->cfqg->nr_cfqq == 1)
1820 return NULL; 1824 return NULL;
1821 1825
1822 /* 1826 /*
1823 * We should notice if some of the queues are cooperating, eg 1827 * We should notice if some of the queues are cooperating, eg
1824 * working closely on the same area of the disk. In that case, 1828 * working closely on the same area of the disk. In that case,
1825 * we can group them together and don't waste time idling. 1829 * we can group them together and don't waste time idling.
1826 */ 1830 */
1827 cfqq = cfqq_close(cfqd, cur_cfqq); 1831 cfqq = cfqq_close(cfqd, cur_cfqq);
1828 if (!cfqq) 1832 if (!cfqq)
1829 return NULL; 1833 return NULL;
1830 1834
1831 /* If new queue belongs to different cfq_group, don't choose it */ 1835 /* If new queue belongs to different cfq_group, don't choose it */
1832 if (cur_cfqq->cfqg != cfqq->cfqg) 1836 if (cur_cfqq->cfqg != cfqq->cfqg)
1833 return NULL; 1837 return NULL;
1834 1838
1835 /* 1839 /*
1836 * It only makes sense to merge sync queues. 1840 * It only makes sense to merge sync queues.
1837 */ 1841 */
1838 if (!cfq_cfqq_sync(cfqq)) 1842 if (!cfq_cfqq_sync(cfqq))
1839 return NULL; 1843 return NULL;
1840 if (CFQQ_SEEKY(cfqq)) 1844 if (CFQQ_SEEKY(cfqq))
1841 return NULL; 1845 return NULL;
1842 1846
1843 /* 1847 /*
1844 * Do not merge queues of different priority classes 1848 * Do not merge queues of different priority classes
1845 */ 1849 */
1846 if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq)) 1850 if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq))
1847 return NULL; 1851 return NULL;
1848 1852
1849 return cfqq; 1853 return cfqq;
1850 } 1854 }
1851 1855
1852 /* 1856 /*
1853 * Determine whether we should enforce idle window for this queue. 1857 * Determine whether we should enforce idle window for this queue.
1854 */ 1858 */
1855 1859
1856 static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) 1860 static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
1857 { 1861 {
1858 enum wl_prio_t prio = cfqq_prio(cfqq); 1862 enum wl_prio_t prio = cfqq_prio(cfqq);
1859 struct cfq_rb_root *service_tree = cfqq->service_tree; 1863 struct cfq_rb_root *service_tree = cfqq->service_tree;
1860 1864
1861 BUG_ON(!service_tree); 1865 BUG_ON(!service_tree);
1862 BUG_ON(!service_tree->count); 1866 BUG_ON(!service_tree->count);
1863 1867
1864 if (!cfqd->cfq_slice_idle) 1868 if (!cfqd->cfq_slice_idle)
1865 return false; 1869 return false;
1866 1870
1867 /* We never do for idle class queues. */ 1871 /* We never do for idle class queues. */
1868 if (prio == IDLE_WORKLOAD) 1872 if (prio == IDLE_WORKLOAD)
1869 return false; 1873 return false;
1870 1874
1871 /* We do for queues that were marked with idle window flag. */ 1875 /* We do for queues that were marked with idle window flag. */
1872 if (cfq_cfqq_idle_window(cfqq) && 1876 if (cfq_cfqq_idle_window(cfqq) &&
1873 !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)) 1877 !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag))
1874 return true; 1878 return true;
1875 1879
1876 /* 1880 /*
1877 * Otherwise, we do only if they are the last ones 1881 * Otherwise, we do only if they are the last ones
1878 * in their service tree. 1882 * in their service tree.
1879 */ 1883 */
1880 if (service_tree->count == 1 && cfq_cfqq_sync(cfqq)) 1884 if (service_tree->count == 1 && cfq_cfqq_sync(cfqq))
1881 return 1; 1885 return 1;
1882 cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", 1886 cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d",
1883 service_tree->count); 1887 service_tree->count);
1884 return 0; 1888 return 0;
1885 } 1889 }
1886 1890
1887 static void cfq_arm_slice_timer(struct cfq_data *cfqd) 1891 static void cfq_arm_slice_timer(struct cfq_data *cfqd)
1888 { 1892 {
1889 struct cfq_queue *cfqq = cfqd->active_queue; 1893 struct cfq_queue *cfqq = cfqd->active_queue;
1890 struct cfq_io_context *cic; 1894 struct cfq_io_context *cic;
1891 unsigned long sl, group_idle = 0; 1895 unsigned long sl, group_idle = 0;
1892 1896
1893 /* 1897 /*
1894 * SSD device without seek penalty, disable idling. But only do so 1898 * SSD device without seek penalty, disable idling. But only do so
1895 * for devices that support queuing, otherwise we still have a problem 1899 * for devices that support queuing, otherwise we still have a problem
1896 * with sync vs async workloads. 1900 * with sync vs async workloads.
1897 */ 1901 */
1898 if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) 1902 if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)
1899 return; 1903 return;
1900 1904
1901 WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); 1905 WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list));
1902 WARN_ON(cfq_cfqq_slice_new(cfqq)); 1906 WARN_ON(cfq_cfqq_slice_new(cfqq));
1903 1907
1904 /* 1908 /*
1905 * idle is disabled, either manually or by past process history 1909 * idle is disabled, either manually or by past process history
1906 */ 1910 */
1907 if (!cfq_should_idle(cfqd, cfqq)) { 1911 if (!cfq_should_idle(cfqd, cfqq)) {
1908 /* no queue idling. Check for group idling */ 1912 /* no queue idling. Check for group idling */
1909 if (cfqd->cfq_group_idle) 1913 if (cfqd->cfq_group_idle)
1910 group_idle = cfqd->cfq_group_idle; 1914 group_idle = cfqd->cfq_group_idle;
1911 else 1915 else
1912 return; 1916 return;
1913 } 1917 }
1914 1918
1915 /* 1919 /*
1916 * still active requests from this queue, don't idle 1920 * still active requests from this queue, don't idle
1917 */ 1921 */
1918 if (cfqq->dispatched) 1922 if (cfqq->dispatched)
1919 return; 1923 return;
1920 1924
1921 /* 1925 /*
1922 * task has exited, don't wait 1926 * task has exited, don't wait
1923 */ 1927 */
1924 cic = cfqd->active_cic; 1928 cic = cfqd->active_cic;
1925 if (!cic || !atomic_read(&cic->ioc->nr_tasks)) 1929 if (!cic || !atomic_read(&cic->ioc->nr_tasks))
1926 return; 1930 return;
1927 1931
1928 /* 1932 /*
1929 * If our average think time is larger than the remaining time 1933 * If our average think time is larger than the remaining time
1930 * slice, then don't idle. This avoids overrunning the allotted 1934 * slice, then don't idle. This avoids overrunning the allotted
1931 * time slice. 1935 * time slice.
1932 */ 1936 */
1933 if (sample_valid(cic->ttime_samples) && 1937 if (sample_valid(cic->ttime_samples) &&
1934 (cfqq->slice_end - jiffies < cic->ttime_mean)) { 1938 (cfqq->slice_end - jiffies < cic->ttime_mean)) {
1935 cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%d", 1939 cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%d",
1936 cic->ttime_mean); 1940 cic->ttime_mean);
1937 return; 1941 return;
1938 } 1942 }
1939 1943
1940 /* There are other queues in the group, don't do group idle */ 1944 /* There are other queues in the group, don't do group idle */
1941 if (group_idle && cfqq->cfqg->nr_cfqq > 1) 1945 if (group_idle && cfqq->cfqg->nr_cfqq > 1)
1942 return; 1946 return;
1943 1947
1944 cfq_mark_cfqq_wait_request(cfqq); 1948 cfq_mark_cfqq_wait_request(cfqq);
1945 1949
1946 if (group_idle) 1950 if (group_idle)
1947 sl = cfqd->cfq_group_idle; 1951 sl = cfqd->cfq_group_idle;
1948 else 1952 else
1949 sl = cfqd->cfq_slice_idle; 1953 sl = cfqd->cfq_slice_idle;
1950 1954
1951 mod_timer(&cfqd->idle_slice_timer, jiffies + sl); 1955 mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
1952 cfq_blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg); 1956 cfq_blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg);
1953 cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu group_idle: %d", sl, 1957 cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu group_idle: %d", sl,
1954 group_idle ? 1 : 0); 1958 group_idle ? 1 : 0);
1955 } 1959 }
1956 1960
1957 /* 1961 /*
1958 * Move request from internal lists to the request queue dispatch list. 1962 * Move request from internal lists to the request queue dispatch list.
1959 */ 1963 */
1960 static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) 1964 static void cfq_dispatch_insert(struct request_queue *q, struct request *rq)
1961 { 1965 {
1962 struct cfq_data *cfqd = q->elevator->elevator_data; 1966 struct cfq_data *cfqd = q->elevator->elevator_data;
1963 struct cfq_queue *cfqq = RQ_CFQQ(rq); 1967 struct cfq_queue *cfqq = RQ_CFQQ(rq);
1964 1968
1965 cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); 1969 cfq_log_cfqq(cfqd, cfqq, "dispatch_insert");
1966 1970
1967 cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); 1971 cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq);
1968 cfq_remove_request(rq); 1972 cfq_remove_request(rq);
1969 cfqq->dispatched++; 1973 cfqq->dispatched++;
1970 (RQ_CFQG(rq))->dispatched++; 1974 (RQ_CFQG(rq))->dispatched++;
1971 elv_dispatch_sort(q, rq); 1975 elv_dispatch_sort(q, rq);
1972 1976
1973 cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++; 1977 cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;
1978 cfqq->nr_sectors += blk_rq_sectors(rq);
1974 cfq_blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq), 1979 cfq_blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq),
1975 rq_data_dir(rq), rq_is_sync(rq)); 1980 rq_data_dir(rq), rq_is_sync(rq));
1976 } 1981 }
1977 1982
1978 /* 1983 /*
1979 * return expired entry, or NULL to just start from scratch in rbtree 1984 * return expired entry, or NULL to just start from scratch in rbtree
1980 */ 1985 */
1981 static struct request *cfq_check_fifo(struct cfq_queue *cfqq) 1986 static struct request *cfq_check_fifo(struct cfq_queue *cfqq)
1982 { 1987 {
1983 struct request *rq = NULL; 1988 struct request *rq = NULL;
1984 1989
1985 if (cfq_cfqq_fifo_expire(cfqq)) 1990 if (cfq_cfqq_fifo_expire(cfqq))
1986 return NULL; 1991 return NULL;
1987 1992
1988 cfq_mark_cfqq_fifo_expire(cfqq); 1993 cfq_mark_cfqq_fifo_expire(cfqq);
1989 1994
1990 if (list_empty(&cfqq->fifo)) 1995 if (list_empty(&cfqq->fifo))
1991 return NULL; 1996 return NULL;
1992 1997
1993 rq = rq_entry_fifo(cfqq->fifo.next); 1998 rq = rq_entry_fifo(cfqq->fifo.next);
1994 if (time_before(jiffies, rq_fifo_time(rq))) 1999 if (time_before(jiffies, rq_fifo_time(rq)))
1995 rq = NULL; 2000 rq = NULL;
1996 2001
1997 cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); 2002 cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq);
1998 return rq; 2003 return rq;
1999 } 2004 }
2000 2005
2001 static inline int 2006 static inline int
2002 cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) 2007 cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
2003 { 2008 {
2004 const int base_rq = cfqd->cfq_slice_async_rq; 2009 const int base_rq = cfqd->cfq_slice_async_rq;
2005 2010
2006 WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); 2011 WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR);
2007 2012
2008 return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio)); 2013 return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio));
2009 } 2014 }
2010 2015
2011 /* 2016 /*
2012 * Must be called with the queue_lock held. 2017 * Must be called with the queue_lock held.
2013 */ 2018 */
2014 static int cfqq_process_refs(struct cfq_queue *cfqq) 2019 static int cfqq_process_refs(struct cfq_queue *cfqq)
2015 { 2020 {
2016 int process_refs, io_refs; 2021 int process_refs, io_refs;
2017 2022
2018 io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE]; 2023 io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE];
2019 process_refs = atomic_read(&cfqq->ref) - io_refs; 2024 process_refs = atomic_read(&cfqq->ref) - io_refs;
2020 BUG_ON(process_refs < 0); 2025 BUG_ON(process_refs < 0);
2021 return process_refs; 2026 return process_refs;
2022 } 2027 }
2023 2028
2024 static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) 2029 static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq)
2025 { 2030 {
2026 int process_refs, new_process_refs; 2031 int process_refs, new_process_refs;
2027 struct cfq_queue *__cfqq; 2032 struct cfq_queue *__cfqq;
2028 2033
2029 /* 2034 /*
2030 * If there are no process references on the new_cfqq, then it is 2035 * If there are no process references on the new_cfqq, then it is
2031 * unsafe to follow the ->new_cfqq chain as other cfqq's in the 2036 * unsafe to follow the ->new_cfqq chain as other cfqq's in the
2032 * chain may have dropped their last reference (not just their 2037 * chain may have dropped their last reference (not just their
2033 * last process reference). 2038 * last process reference).
2034 */ 2039 */
2035 if (!cfqq_process_refs(new_cfqq)) 2040 if (!cfqq_process_refs(new_cfqq))
2036 return; 2041 return;
2037 2042
2038 /* Avoid a circular list and skip interim queue merges */ 2043 /* Avoid a circular list and skip interim queue merges */
2039 while ((__cfqq = new_cfqq->new_cfqq)) { 2044 while ((__cfqq = new_cfqq->new_cfqq)) {
2040 if (__cfqq == cfqq) 2045 if (__cfqq == cfqq)
2041 return; 2046 return;
2042 new_cfqq = __cfqq; 2047 new_cfqq = __cfqq;
2043 } 2048 }
2044 2049
2045 process_refs = cfqq_process_refs(cfqq); 2050 process_refs = cfqq_process_refs(cfqq);
2046 new_process_refs = cfqq_process_refs(new_cfqq); 2051 new_process_refs = cfqq_process_refs(new_cfqq);
2047 /* 2052 /*
2048 * If the process for the cfqq has gone away, there is no 2053 * If the process for the cfqq has gone away, there is no
2049 * sense in merging the queues. 2054 * sense in merging the queues.
2050 */ 2055 */
2051 if (process_refs == 0 || new_process_refs == 0) 2056 if (process_refs == 0 || new_process_refs == 0)
2052 return; 2057 return;
2053 2058
2054 /* 2059 /*
2055 * Merge in the direction of the lesser amount of work. 2060 * Merge in the direction of the lesser amount of work.
2056 */ 2061 */
2057 if (new_process_refs >= process_refs) { 2062 if (new_process_refs >= process_refs) {
2058 cfqq->new_cfqq = new_cfqq; 2063 cfqq->new_cfqq = new_cfqq;
2059 atomic_add(process_refs, &new_cfqq->ref); 2064 atomic_add(process_refs, &new_cfqq->ref);
2060 } else { 2065 } else {
2061 new_cfqq->new_cfqq = cfqq; 2066 new_cfqq->new_cfqq = cfqq;
2062 atomic_add(new_process_refs, &cfqq->ref); 2067 atomic_add(new_process_refs, &cfqq->ref);
2063 } 2068 }
2064 } 2069 }
2065 2070
2066 static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, 2071 static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd,
2067 struct cfq_group *cfqg, enum wl_prio_t prio) 2072 struct cfq_group *cfqg, enum wl_prio_t prio)
2068 { 2073 {
2069 struct cfq_queue *queue; 2074 struct cfq_queue *queue;
2070 int i; 2075 int i;
2071 bool key_valid = false; 2076 bool key_valid = false;
2072 unsigned long lowest_key = 0; 2077 unsigned long lowest_key = 0;
2073 enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; 2078 enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD;
2074 2079
2075 for (i = 0; i <= SYNC_WORKLOAD; ++i) { 2080 for (i = 0; i <= SYNC_WORKLOAD; ++i) {
2076 /* select the one with lowest rb_key */ 2081 /* select the one with lowest rb_key */
2077 queue = cfq_rb_first(service_tree_for(cfqg, prio, i)); 2082 queue = cfq_rb_first(service_tree_for(cfqg, prio, i));
2078 if (queue && 2083 if (queue &&
2079 (!key_valid || time_before(queue->rb_key, lowest_key))) { 2084 (!key_valid || time_before(queue->rb_key, lowest_key))) {
2080 lowest_key = queue->rb_key; 2085 lowest_key = queue->rb_key;
2081 cur_best = i; 2086 cur_best = i;
2082 key_valid = true; 2087 key_valid = true;
2083 } 2088 }
2084 } 2089 }
2085 2090
2086 return cur_best; 2091 return cur_best;
2087 } 2092 }
2088 2093
2089 static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg) 2094 static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
2090 { 2095 {
2091 unsigned slice; 2096 unsigned slice;
2092 unsigned count; 2097 unsigned count;
2093 struct cfq_rb_root *st; 2098 struct cfq_rb_root *st;
2094 unsigned group_slice; 2099 unsigned group_slice;
2095 2100
2096 if (!cfqg) { 2101 if (!cfqg) {
2097 cfqd->serving_prio = IDLE_WORKLOAD; 2102 cfqd->serving_prio = IDLE_WORKLOAD;
2098 cfqd->workload_expires = jiffies + 1; 2103 cfqd->workload_expires = jiffies + 1;
2099 return; 2104 return;
2100 } 2105 }
2101 2106
2102 /* Choose next priority. RT > BE > IDLE */ 2107 /* Choose next priority. RT > BE > IDLE */
2103 if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) 2108 if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg))
2104 cfqd->serving_prio = RT_WORKLOAD; 2109 cfqd->serving_prio = RT_WORKLOAD;
2105 else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg)) 2110 else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg))
2106 cfqd->serving_prio = BE_WORKLOAD; 2111 cfqd->serving_prio = BE_WORKLOAD;
2107 else { 2112 else {
2108 cfqd->serving_prio = IDLE_WORKLOAD; 2113 cfqd->serving_prio = IDLE_WORKLOAD;
2109 cfqd->workload_expires = jiffies + 1; 2114 cfqd->workload_expires = jiffies + 1;
2110 return; 2115 return;
2111 } 2116 }
2112 2117
2113 /* 2118 /*
2114 * For RT and BE, we have to choose also the type 2119 * For RT and BE, we have to choose also the type
2115 * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload 2120 * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload
2116 * expiration time 2121 * expiration time
2117 */ 2122 */
2118 st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type); 2123 st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type);
2119 count = st->count; 2124 count = st->count;
2120 2125
2121 /* 2126 /*
2122 * check workload expiration, and that we still have other queues ready 2127 * check workload expiration, and that we still have other queues ready
2123 */ 2128 */
2124 if (count && !time_after(jiffies, cfqd->workload_expires)) 2129 if (count && !time_after(jiffies, cfqd->workload_expires))
2125 return; 2130 return;
2126 2131
2127 /* otherwise select new workload type */ 2132 /* otherwise select new workload type */
2128 cfqd->serving_type = 2133 cfqd->serving_type =
2129 cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio); 2134 cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio);
2130 st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type); 2135 st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type);
2131 count = st->count; 2136 count = st->count;
2132 2137
2133 /* 2138 /*
2134 * the workload slice is computed as a fraction of target latency 2139 * the workload slice is computed as a fraction of target latency
2135 * proportional to the number of queues in that workload, over 2140 * proportional to the number of queues in that workload, over
2136 * all the queues in the same priority class 2141 * all the queues in the same priority class
2137 */ 2142 */
2138 group_slice = cfq_group_slice(cfqd, cfqg); 2143 group_slice = cfq_group_slice(cfqd, cfqg);
2139 2144
2140 slice = group_slice * count / 2145 slice = group_slice * count /
2141 max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_prio], 2146 max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_prio],
2142 cfq_group_busy_queues_wl(cfqd->serving_prio, cfqd, cfqg)); 2147 cfq_group_busy_queues_wl(cfqd->serving_prio, cfqd, cfqg));
2143 2148
2144 if (cfqd->serving_type == ASYNC_WORKLOAD) { 2149 if (cfqd->serving_type == ASYNC_WORKLOAD) {
2145 unsigned int tmp; 2150 unsigned int tmp;
2146 2151
2147 /* 2152 /*
2148 * Async queues are currently system wide. Just taking 2153 * Async queues are currently system wide. Just taking
2149 * proportion of queues with-in same group will lead to higher 2154 * proportion of queues with-in same group will lead to higher
2150 * async ratio system wide as generally root group is going 2155 * async ratio system wide as generally root group is going
2151 * to have higher weight. A more accurate thing would be to 2156 * to have higher weight. A more accurate thing would be to
2152 * calculate system wide asnc/sync ratio. 2157 * calculate system wide asnc/sync ratio.
2153 */ 2158 */
2154 tmp = cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg); 2159 tmp = cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg);
2155 tmp = tmp/cfqd->busy_queues; 2160 tmp = tmp/cfqd->busy_queues;
2156 slice = min_t(unsigned, slice, tmp); 2161 slice = min_t(unsigned, slice, tmp);
2157 2162
2158 /* async workload slice is scaled down according to 2163 /* async workload slice is scaled down according to
2159 * the sync/async slice ratio. */ 2164 * the sync/async slice ratio. */
2160 slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1]; 2165 slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1];
2161 } else 2166 } else
2162 /* sync workload slice is at least 2 * cfq_slice_idle */ 2167 /* sync workload slice is at least 2 * cfq_slice_idle */
2163 slice = max(slice, 2 * cfqd->cfq_slice_idle); 2168 slice = max(slice, 2 * cfqd->cfq_slice_idle);
2164 2169
2165 slice = max_t(unsigned, slice, CFQ_MIN_TT); 2170 slice = max_t(unsigned, slice, CFQ_MIN_TT);
2166 cfq_log(cfqd, "workload slice:%d", slice); 2171 cfq_log(cfqd, "workload slice:%d", slice);
2167 cfqd->workload_expires = jiffies + slice; 2172 cfqd->workload_expires = jiffies + slice;
2168 cfqd->noidle_tree_requires_idle = false; 2173 cfqd->noidle_tree_requires_idle = false;
2169 } 2174 }
2170 2175
2171 static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) 2176 static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd)
2172 { 2177 {
2173 struct cfq_rb_root *st = &cfqd->grp_service_tree; 2178 struct cfq_rb_root *st = &cfqd->grp_service_tree;
2174 struct cfq_group *cfqg; 2179 struct cfq_group *cfqg;
2175 2180
2176 if (RB_EMPTY_ROOT(&st->rb)) 2181 if (RB_EMPTY_ROOT(&st->rb))
2177 return NULL; 2182 return NULL;
2178 cfqg = cfq_rb_first_group(st); 2183 cfqg = cfq_rb_first_group(st);
2179 st->active = &cfqg->rb_node; 2184 st->active = &cfqg->rb_node;
2180 update_min_vdisktime(st); 2185 update_min_vdisktime(st);
2181 return cfqg; 2186 return cfqg;
2182 } 2187 }
2183 2188
2184 static void cfq_choose_cfqg(struct cfq_data *cfqd) 2189 static void cfq_choose_cfqg(struct cfq_data *cfqd)
2185 { 2190 {
2186 struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); 2191 struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd);
2187 2192
2188 cfqd->serving_group = cfqg; 2193 cfqd->serving_group = cfqg;
2189 2194
2190 /* Restore the workload type data */ 2195 /* Restore the workload type data */
2191 if (cfqg->saved_workload_slice) { 2196 if (cfqg->saved_workload_slice) {
2192 cfqd->workload_expires = jiffies + cfqg->saved_workload_slice; 2197 cfqd->workload_expires = jiffies + cfqg->saved_workload_slice;
2193 cfqd->serving_type = cfqg->saved_workload; 2198 cfqd->serving_type = cfqg->saved_workload;
2194 cfqd->serving_prio = cfqg->saved_serving_prio; 2199 cfqd->serving_prio = cfqg->saved_serving_prio;
2195 } else 2200 } else
2196 cfqd->workload_expires = jiffies - 1; 2201 cfqd->workload_expires = jiffies - 1;
2197 2202
2198 choose_service_tree(cfqd, cfqg); 2203 choose_service_tree(cfqd, cfqg);
2199 } 2204 }
2200 2205
2201 /* 2206 /*
2202 * Select a queue for service. If we have a current active queue, 2207 * Select a queue for service. If we have a current active queue,
2203 * check whether to continue servicing it, or retrieve and set a new one. 2208 * check whether to continue servicing it, or retrieve and set a new one.
2204 */ 2209 */
2205 static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) 2210 static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
2206 { 2211 {
2207 struct cfq_queue *cfqq, *new_cfqq = NULL; 2212 struct cfq_queue *cfqq, *new_cfqq = NULL;
2208 2213
2209 cfqq = cfqd->active_queue; 2214 cfqq = cfqd->active_queue;
2210 if (!cfqq) 2215 if (!cfqq)
2211 goto new_queue; 2216 goto new_queue;
2212 2217
2213 if (!cfqd->rq_queued) 2218 if (!cfqd->rq_queued)
2214 return NULL; 2219 return NULL;
2215 2220
2216 /* 2221 /*
2217 * We were waiting for group to get backlogged. Expire the queue 2222 * We were waiting for group to get backlogged. Expire the queue
2218 */ 2223 */
2219 if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list)) 2224 if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list))
2220 goto expire; 2225 goto expire;
2221 2226
2222 /* 2227 /*
2223 * The active queue has run out of time, expire it and select new. 2228 * The active queue has run out of time, expire it and select new.
2224 */ 2229 */
2225 if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) { 2230 if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) {
2226 /* 2231 /*
2227 * If slice had not expired at the completion of last request 2232 * If slice had not expired at the completion of last request
2228 * we might not have turned on wait_busy flag. Don't expire 2233 * we might not have turned on wait_busy flag. Don't expire
2229 * the queue yet. Allow the group to get backlogged. 2234 * the queue yet. Allow the group to get backlogged.
2230 * 2235 *
2231 * The very fact that we have used the slice, that means we 2236 * The very fact that we have used the slice, that means we
2232 * have been idling all along on this queue and it should be 2237 * have been idling all along on this queue and it should be
2233 * ok to wait for this request to complete. 2238 * ok to wait for this request to complete.
2234 */ 2239 */
2235 if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list) 2240 if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list)
2236 && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { 2241 && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) {
2237 cfqq = NULL; 2242 cfqq = NULL;
2238 goto keep_queue; 2243 goto keep_queue;
2239 } else 2244 } else
2240 goto check_group_idle; 2245 goto check_group_idle;
2241 } 2246 }
2242 2247
2243 /* 2248 /*
2244 * The active queue has requests and isn't expired, allow it to 2249 * The active queue has requests and isn't expired, allow it to
2245 * dispatch. 2250 * dispatch.
2246 */ 2251 */
2247 if (!RB_EMPTY_ROOT(&cfqq->sort_list)) 2252 if (!RB_EMPTY_ROOT(&cfqq->sort_list))
2248 goto keep_queue; 2253 goto keep_queue;
2249 2254
2250 /* 2255 /*
2251 * If another queue has a request waiting within our mean seek 2256 * If another queue has a request waiting within our mean seek
2252 * distance, let it run. The expire code will check for close 2257 * distance, let it run. The expire code will check for close
2253 * cooperators and put the close queue at the front of the service 2258 * cooperators and put the close queue at the front of the service
2254 * tree. If possible, merge the expiring queue with the new cfqq. 2259 * tree. If possible, merge the expiring queue with the new cfqq.
2255 */ 2260 */
2256 new_cfqq = cfq_close_cooperator(cfqd, cfqq); 2261 new_cfqq = cfq_close_cooperator(cfqd, cfqq);
2257 if (new_cfqq) { 2262 if (new_cfqq) {
2258 if (!cfqq->new_cfqq) 2263 if (!cfqq->new_cfqq)
2259 cfq_setup_merge(cfqq, new_cfqq); 2264 cfq_setup_merge(cfqq, new_cfqq);
2260 goto expire; 2265 goto expire;
2261 } 2266 }
2262 2267
2263 /* 2268 /*
2264 * No requests pending. If the active queue still has requests in 2269 * No requests pending. If the active queue still has requests in
2265 * flight or is idling for a new request, allow either of these 2270 * flight or is idling for a new request, allow either of these
2266 * conditions to happen (or time out) before selecting a new queue. 2271 * conditions to happen (or time out) before selecting a new queue.
2267 */ 2272 */
2268 if (timer_pending(&cfqd->idle_slice_timer)) { 2273 if (timer_pending(&cfqd->idle_slice_timer)) {
2269 cfqq = NULL; 2274 cfqq = NULL;
2270 goto keep_queue; 2275 goto keep_queue;
2271 } 2276 }
2272 2277
2273 if (cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { 2278 if (cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) {
2274 cfqq = NULL; 2279 cfqq = NULL;
2275 goto keep_queue; 2280 goto keep_queue;
2276 } 2281 }
2277 2282
2278 /* 2283 /*
2279 * If group idle is enabled and there are requests dispatched from 2284 * If group idle is enabled and there are requests dispatched from
2280 * this group, wait for requests to complete. 2285 * this group, wait for requests to complete.
2281 */ 2286 */
2282 check_group_idle: 2287 check_group_idle:
2283 if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 2288 if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1
2284 && cfqq->cfqg->dispatched) { 2289 && cfqq->cfqg->dispatched) {
2285 cfqq = NULL; 2290 cfqq = NULL;
2286 goto keep_queue; 2291 goto keep_queue;
2287 } 2292 }
2288 2293
2289 expire: 2294 expire:
2290 cfq_slice_expired(cfqd, 0); 2295 cfq_slice_expired(cfqd, 0);
2291 new_queue: 2296 new_queue:
2292 /* 2297 /*
2293 * Current queue expired. Check if we have to switch to a new 2298 * Current queue expired. Check if we have to switch to a new
2294 * service tree 2299 * service tree
2295 */ 2300 */
2296 if (!new_cfqq) 2301 if (!new_cfqq)
2297 cfq_choose_cfqg(cfqd); 2302 cfq_choose_cfqg(cfqd);
2298 2303
2299 cfqq = cfq_set_active_queue(cfqd, new_cfqq); 2304 cfqq = cfq_set_active_queue(cfqd, new_cfqq);
2300 keep_queue: 2305 keep_queue:
2301 return cfqq; 2306 return cfqq;
2302 } 2307 }
2303 2308
2304 static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) 2309 static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
2305 { 2310 {
2306 int dispatched = 0; 2311 int dispatched = 0;
2307 2312
2308 while (cfqq->next_rq) { 2313 while (cfqq->next_rq) {
2309 cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); 2314 cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq);
2310 dispatched++; 2315 dispatched++;
2311 } 2316 }
2312 2317
2313 BUG_ON(!list_empty(&cfqq->fifo)); 2318 BUG_ON(!list_empty(&cfqq->fifo));
2314 2319
2315 /* By default cfqq is not expired if it is empty. Do it explicitly */ 2320 /* By default cfqq is not expired if it is empty. Do it explicitly */
2316 __cfq_slice_expired(cfqq->cfqd, cfqq, 0); 2321 __cfq_slice_expired(cfqq->cfqd, cfqq, 0);
2317 return dispatched; 2322 return dispatched;
2318 } 2323 }
2319 2324
2320 /* 2325 /*
2321 * Drain our current requests. Used for barriers and when switching 2326 * Drain our current requests. Used for barriers and when switching
2322 * io schedulers on-the-fly. 2327 * io schedulers on-the-fly.
2323 */ 2328 */
2324 static int cfq_forced_dispatch(struct cfq_data *cfqd) 2329 static int cfq_forced_dispatch(struct cfq_data *cfqd)
2325 { 2330 {
2326 struct cfq_queue *cfqq; 2331 struct cfq_queue *cfqq;
2327 int dispatched = 0; 2332 int dispatched = 0;
2328 2333
2329 /* Expire the timeslice of the current active queue first */ 2334 /* Expire the timeslice of the current active queue first */
2330 cfq_slice_expired(cfqd, 0); 2335 cfq_slice_expired(cfqd, 0);
2331 while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) { 2336 while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) {
2332 __cfq_set_active_queue(cfqd, cfqq); 2337 __cfq_set_active_queue(cfqd, cfqq);
2333 dispatched += __cfq_forced_dispatch_cfqq(cfqq); 2338 dispatched += __cfq_forced_dispatch_cfqq(cfqq);
2334 } 2339 }
2335 2340
2336 BUG_ON(cfqd->busy_queues); 2341 BUG_ON(cfqd->busy_queues);
2337 2342
2338 cfq_log(cfqd, "forced_dispatch=%d", dispatched); 2343 cfq_log(cfqd, "forced_dispatch=%d", dispatched);
2339 return dispatched; 2344 return dispatched;
2340 } 2345 }
2341 2346
2342 static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, 2347 static inline bool cfq_slice_used_soon(struct cfq_data *cfqd,
2343 struct cfq_queue *cfqq) 2348 struct cfq_queue *cfqq)
2344 { 2349 {
2345 /* the queue hasn't finished any request, can't estimate */ 2350 /* the queue hasn't finished any request, can't estimate */
2346 if (cfq_cfqq_slice_new(cfqq)) 2351 if (cfq_cfqq_slice_new(cfqq))
2347 return 1; 2352 return 1;
2348 if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched, 2353 if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched,
2349 cfqq->slice_end)) 2354 cfqq->slice_end))
2350 return 1; 2355 return 1;
2351 2356
2352 return 0; 2357 return 0;
2353 } 2358 }
2354 2359
2355 static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) 2360 static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq)
2356 { 2361 {
2357 unsigned int max_dispatch; 2362 unsigned int max_dispatch;
2358 2363
2359 /* 2364 /*
2360 * Drain async requests before we start sync IO 2365 * Drain async requests before we start sync IO
2361 */ 2366 */
2362 if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_flight[BLK_RW_ASYNC]) 2367 if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_flight[BLK_RW_ASYNC])
2363 return false; 2368 return false;
2364 2369
2365 /* 2370 /*
2366 * If this is an async queue and we have sync IO in flight, let it wait 2371 * If this is an async queue and we have sync IO in flight, let it wait
2367 */ 2372 */
2368 if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq)) 2373 if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq))
2369 return false; 2374 return false;
2370 2375
2371 max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1); 2376 max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1);
2372 if (cfq_class_idle(cfqq)) 2377 if (cfq_class_idle(cfqq))
2373 max_dispatch = 1; 2378 max_dispatch = 1;
2374 2379
2375 /* 2380 /*
2376 * Does this cfqq already have too much IO in flight? 2381 * Does this cfqq already have too much IO in flight?
2377 */ 2382 */
2378 if (cfqq->dispatched >= max_dispatch) { 2383 if (cfqq->dispatched >= max_dispatch) {
2379 /* 2384 /*
2380 * idle queue must always only have a single IO in flight 2385 * idle queue must always only have a single IO in flight
2381 */ 2386 */
2382 if (cfq_class_idle(cfqq)) 2387 if (cfq_class_idle(cfqq))
2383 return false; 2388 return false;
2384 2389
2385 /* 2390 /*
2386 * We have other queues, don't allow more IO from this one 2391 * We have other queues, don't allow more IO from this one
2387 */ 2392 */
2388 if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq)) 2393 if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq))
2389 return false; 2394 return false;
2390 2395
2391 /* 2396 /*
2392 * Sole queue user, no limit 2397 * Sole queue user, no limit
2393 */ 2398 */
2394 if (cfqd->busy_queues == 1) 2399 if (cfqd->busy_queues == 1)
2395 max_dispatch = -1; 2400 max_dispatch = -1;
2396 else 2401 else
2397 /* 2402 /*
2398 * Normally we start throttling cfqq when cfq_quantum/2 2403 * Normally we start throttling cfqq when cfq_quantum/2
2399 * requests have been dispatched. But we can drive 2404 * requests have been dispatched. But we can drive
2400 * deeper queue depths at the beginning of slice 2405 * deeper queue depths at the beginning of slice
2401 * subjected to upper limit of cfq_quantum. 2406 * subjected to upper limit of cfq_quantum.
2402 * */ 2407 * */
2403 max_dispatch = cfqd->cfq_quantum; 2408 max_dispatch = cfqd->cfq_quantum;
2404 } 2409 }
2405 2410
2406 /* 2411 /*
2407 * Async queues must wait a bit before being allowed dispatch. 2412 * Async queues must wait a bit before being allowed dispatch.
2408 * We also ramp up the dispatch depth gradually for async IO, 2413 * We also ramp up the dispatch depth gradually for async IO,
2409 * based on the last sync IO we serviced 2414 * based on the last sync IO we serviced
2410 */ 2415 */
2411 if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { 2416 if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) {
2412 unsigned long last_sync = jiffies - cfqd->last_delayed_sync; 2417 unsigned long last_sync = jiffies - cfqd->last_delayed_sync;
2413 unsigned int depth; 2418 unsigned int depth;
2414 2419
2415 depth = last_sync / cfqd->cfq_slice[1]; 2420 depth = last_sync / cfqd->cfq_slice[1];
2416 if (!depth && !cfqq->dispatched) 2421 if (!depth && !cfqq->dispatched)
2417 depth = 1; 2422 depth = 1;
2418 if (depth < max_dispatch) 2423 if (depth < max_dispatch)
2419 max_dispatch = depth; 2424 max_dispatch = depth;
2420 } 2425 }
2421 2426
2422 /* 2427 /*
2423 * If we're below the current max, allow a dispatch 2428 * If we're below the current max, allow a dispatch
2424 */ 2429 */
2425 return cfqq->dispatched < max_dispatch; 2430 return cfqq->dispatched < max_dispatch;
2426 } 2431 }
2427 2432
2428 /* 2433 /*
2429 * Dispatch a request from cfqq, moving them to the request queue 2434 * Dispatch a request from cfqq, moving them to the request queue
2430 * dispatch list. 2435 * dispatch list.
2431 */ 2436 */
2432 static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) 2437 static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq)
2433 { 2438 {
2434 struct request *rq; 2439 struct request *rq;
2435 2440
2436 BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); 2441 BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list));
2437 2442
2438 if (!cfq_may_dispatch(cfqd, cfqq)) 2443 if (!cfq_may_dispatch(cfqd, cfqq))
2439 return false; 2444 return false;
2440 2445
2441 /* 2446 /*
2442 * follow expired path, else get first next available 2447 * follow expired path, else get first next available
2443 */ 2448 */
2444 rq = cfq_check_fifo(cfqq); 2449 rq = cfq_check_fifo(cfqq);
2445 if (!rq) 2450 if (!rq)
2446 rq = cfqq->next_rq; 2451 rq = cfqq->next_rq;
2447 2452
2448 /* 2453 /*
2449 * insert request into driver dispatch list 2454 * insert request into driver dispatch list
2450 */ 2455 */
2451 cfq_dispatch_insert(cfqd->queue, rq); 2456 cfq_dispatch_insert(cfqd->queue, rq);
2452 2457
2453 if (!cfqd->active_cic) { 2458 if (!cfqd->active_cic) {
2454 struct cfq_io_context *cic = RQ_CIC(rq); 2459 struct cfq_io_context *cic = RQ_CIC(rq);
2455 2460
2456 atomic_long_inc(&cic->ioc->refcount); 2461 atomic_long_inc(&cic->ioc->refcount);
2457 cfqd->active_cic = cic; 2462 cfqd->active_cic = cic;
2458 } 2463 }
2459 2464
2460 return true; 2465 return true;
2461 } 2466 }
2462 2467
2463 /* 2468 /*
2464 * Find the cfqq that we need to service and move a request from that to the 2469 * Find the cfqq that we need to service and move a request from that to the
2465 * dispatch list 2470 * dispatch list
2466 */ 2471 */
2467 static int cfq_dispatch_requests(struct request_queue *q, int force) 2472 static int cfq_dispatch_requests(struct request_queue *q, int force)
2468 { 2473 {
2469 struct cfq_data *cfqd = q->elevator->elevator_data; 2474 struct cfq_data *cfqd = q->elevator->elevator_data;
2470 struct cfq_queue *cfqq; 2475 struct cfq_queue *cfqq;
2471 2476
2472 if (!cfqd->busy_queues) 2477 if (!cfqd->busy_queues)
2473 return 0; 2478 return 0;
2474 2479
2475 if (unlikely(force)) 2480 if (unlikely(force))
2476 return cfq_forced_dispatch(cfqd); 2481 return cfq_forced_dispatch(cfqd);
2477 2482
2478 cfqq = cfq_select_queue(cfqd); 2483 cfqq = cfq_select_queue(cfqd);
2479 if (!cfqq) 2484 if (!cfqq)
2480 return 0; 2485 return 0;
2481 2486
2482 /* 2487 /*
2483 * Dispatch a request from this cfqq, if it is allowed 2488 * Dispatch a request from this cfqq, if it is allowed
2484 */ 2489 */
2485 if (!cfq_dispatch_request(cfqd, cfqq)) 2490 if (!cfq_dispatch_request(cfqd, cfqq))
2486 return 0; 2491 return 0;
2487 2492
2488 cfqq->slice_dispatch++; 2493 cfqq->slice_dispatch++;
2489 cfq_clear_cfqq_must_dispatch(cfqq); 2494 cfq_clear_cfqq_must_dispatch(cfqq);
2490 2495
2491 /* 2496 /*
2492 * expire an async queue immediately if it has used up its slice. idle 2497 * expire an async queue immediately if it has used up its slice. idle
2493 * queue always expire after 1 dispatch round. 2498 * queue always expire after 1 dispatch round.
2494 */ 2499 */
2495 if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && 2500 if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) &&
2496 cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || 2501 cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) ||
2497 cfq_class_idle(cfqq))) { 2502 cfq_class_idle(cfqq))) {
2498 cfqq->slice_end = jiffies + 1; 2503 cfqq->slice_end = jiffies + 1;
2499 cfq_slice_expired(cfqd, 0); 2504 cfq_slice_expired(cfqd, 0);
2500 } 2505 }
2501 2506
2502 cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); 2507 cfq_log_cfqq(cfqd, cfqq, "dispatched a request");
2503 return 1; 2508 return 1;
2504 } 2509 }
2505 2510
2506 /* 2511 /*
2507 * task holds one reference to the queue, dropped when task exits. each rq 2512 * task holds one reference to the queue, dropped when task exits. each rq
2508 * in-flight on this queue also holds a reference, dropped when rq is freed. 2513 * in-flight on this queue also holds a reference, dropped when rq is freed.
2509 * 2514 *
2510 * Each cfq queue took a reference on the parent group. Drop it now. 2515 * Each cfq queue took a reference on the parent group. Drop it now.
2511 * queue lock must be held here. 2516 * queue lock must be held here.
2512 */ 2517 */
2513 static void cfq_put_queue(struct cfq_queue *cfqq) 2518 static void cfq_put_queue(struct cfq_queue *cfqq)
2514 { 2519 {
2515 struct cfq_data *cfqd = cfqq->cfqd; 2520 struct cfq_data *cfqd = cfqq->cfqd;
2516 struct cfq_group *cfqg, *orig_cfqg; 2521 struct cfq_group *cfqg, *orig_cfqg;
2517 2522
2518 BUG_ON(atomic_read(&cfqq->ref) <= 0); 2523 BUG_ON(atomic_read(&cfqq->ref) <= 0);
2519 2524
2520 if (!atomic_dec_and_test(&cfqq->ref)) 2525 if (!atomic_dec_and_test(&cfqq->ref))
2521 return; 2526 return;
2522 2527
2523 cfq_log_cfqq(cfqd, cfqq, "put_queue"); 2528 cfq_log_cfqq(cfqd, cfqq, "put_queue");
2524 BUG_ON(rb_first(&cfqq->sort_list)); 2529 BUG_ON(rb_first(&cfqq->sort_list));
2525 BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); 2530 BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]);
2526 cfqg = cfqq->cfqg; 2531 cfqg = cfqq->cfqg;
2527 orig_cfqg = cfqq->orig_cfqg; 2532 orig_cfqg = cfqq->orig_cfqg;
2528 2533
2529 if (unlikely(cfqd->active_queue == cfqq)) { 2534 if (unlikely(cfqd->active_queue == cfqq)) {
2530 __cfq_slice_expired(cfqd, cfqq, 0); 2535 __cfq_slice_expired(cfqd, cfqq, 0);
2531 cfq_schedule_dispatch(cfqd); 2536 cfq_schedule_dispatch(cfqd);
2532 } 2537 }
2533 2538
2534 BUG_ON(cfq_cfqq_on_rr(cfqq)); 2539 BUG_ON(cfq_cfqq_on_rr(cfqq));
2535 kmem_cache_free(cfq_pool, cfqq); 2540 kmem_cache_free(cfq_pool, cfqq);
2536 cfq_put_cfqg(cfqg); 2541 cfq_put_cfqg(cfqg);
2537 if (orig_cfqg) 2542 if (orig_cfqg)
2538 cfq_put_cfqg(orig_cfqg); 2543 cfq_put_cfqg(orig_cfqg);
2539 } 2544 }
2540 2545
2541 /* 2546 /*
2542 * Must always be called with the rcu_read_lock() held 2547 * Must always be called with the rcu_read_lock() held
2543 */ 2548 */
2544 static void 2549 static void
2545 __call_for_each_cic(struct io_context *ioc, 2550 __call_for_each_cic(struct io_context *ioc,
2546 void (*func)(struct io_context *, struct cfq_io_context *)) 2551 void (*func)(struct io_context *, struct cfq_io_context *))
2547 { 2552 {
2548 struct cfq_io_context *cic; 2553 struct cfq_io_context *cic;
2549 struct hlist_node *n; 2554 struct hlist_node *n;
2550 2555
2551 hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) 2556 hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list)
2552 func(ioc, cic); 2557 func(ioc, cic);
2553 } 2558 }
2554 2559
2555 /* 2560 /*
2556 * Call func for each cic attached to this ioc. 2561 * Call func for each cic attached to this ioc.
2557 */ 2562 */
2558 static void 2563 static void
2559 call_for_each_cic(struct io_context *ioc, 2564 call_for_each_cic(struct io_context *ioc,
2560 void (*func)(struct io_context *, struct cfq_io_context *)) 2565 void (*func)(struct io_context *, struct cfq_io_context *))
2561 { 2566 {
2562 rcu_read_lock(); 2567 rcu_read_lock();
2563 __call_for_each_cic(ioc, func); 2568 __call_for_each_cic(ioc, func);
2564 rcu_read_unlock(); 2569 rcu_read_unlock();
2565 } 2570 }
2566 2571
2567 static void cfq_cic_free_rcu(struct rcu_head *head) 2572 static void cfq_cic_free_rcu(struct rcu_head *head)
2568 { 2573 {
2569 struct cfq_io_context *cic; 2574 struct cfq_io_context *cic;
2570 2575
2571 cic = container_of(head, struct cfq_io_context, rcu_head); 2576 cic = container_of(head, struct cfq_io_context, rcu_head);
2572 2577
2573 kmem_cache_free(cfq_ioc_pool, cic); 2578 kmem_cache_free(cfq_ioc_pool, cic);
2574 elv_ioc_count_dec(cfq_ioc_count); 2579 elv_ioc_count_dec(cfq_ioc_count);
2575 2580
2576 if (ioc_gone) { 2581 if (ioc_gone) {
2577 /* 2582 /*
2578 * CFQ scheduler is exiting, grab exit lock and check 2583 * CFQ scheduler is exiting, grab exit lock and check
2579 * the pending io context count. If it hits zero, 2584 * the pending io context count. If it hits zero,
2580 * complete ioc_gone and set it back to NULL 2585 * complete ioc_gone and set it back to NULL
2581 */ 2586 */
2582 spin_lock(&ioc_gone_lock); 2587 spin_lock(&ioc_gone_lock);
2583 if (ioc_gone && !elv_ioc_count_read(cfq_ioc_count)) { 2588 if (ioc_gone && !elv_ioc_count_read(cfq_ioc_count)) {
2584 complete(ioc_gone); 2589 complete(ioc_gone);
2585 ioc_gone = NULL; 2590 ioc_gone = NULL;
2586 } 2591 }
2587 spin_unlock(&ioc_gone_lock); 2592 spin_unlock(&ioc_gone_lock);
2588 } 2593 }
2589 } 2594 }
2590 2595
2591 static void cfq_cic_free(struct cfq_io_context *cic) 2596 static void cfq_cic_free(struct cfq_io_context *cic)
2592 { 2597 {
2593 call_rcu(&cic->rcu_head, cfq_cic_free_rcu); 2598 call_rcu(&cic->rcu_head, cfq_cic_free_rcu);
2594 } 2599 }
2595 2600
2596 static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) 2601 static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic)
2597 { 2602 {
2598 unsigned long flags; 2603 unsigned long flags;
2599 unsigned long dead_key = (unsigned long) cic->key; 2604 unsigned long dead_key = (unsigned long) cic->key;
2600 2605
2601 BUG_ON(!(dead_key & CIC_DEAD_KEY)); 2606 BUG_ON(!(dead_key & CIC_DEAD_KEY));
2602 2607
2603 spin_lock_irqsave(&ioc->lock, flags); 2608 spin_lock_irqsave(&ioc->lock, flags);
2604 radix_tree_delete(&ioc->radix_root, dead_key >> CIC_DEAD_INDEX_SHIFT); 2609 radix_tree_delete(&ioc->radix_root, dead_key >> CIC_DEAD_INDEX_SHIFT);
2605 hlist_del_rcu(&cic->cic_list); 2610 hlist_del_rcu(&cic->cic_list);
2606 spin_unlock_irqrestore(&ioc->lock, flags); 2611 spin_unlock_irqrestore(&ioc->lock, flags);
2607 2612
2608 cfq_cic_free(cic); 2613 cfq_cic_free(cic);
2609 } 2614 }
2610 2615
2611 /* 2616 /*
2612 * Must be called with rcu_read_lock() held or preemption otherwise disabled. 2617 * Must be called with rcu_read_lock() held or preemption otherwise disabled.
2613 * Only two callers of this - ->dtor() which is called with the rcu_read_lock(), 2618 * Only two callers of this - ->dtor() which is called with the rcu_read_lock(),
2614 * and ->trim() which is called with the task lock held 2619 * and ->trim() which is called with the task lock held
2615 */ 2620 */
2616 static void cfq_free_io_context(struct io_context *ioc) 2621 static void cfq_free_io_context(struct io_context *ioc)
2617 { 2622 {
2618 /* 2623 /*
2619 * ioc->refcount is zero here, or we are called from elv_unregister(), 2624 * ioc->refcount is zero here, or we are called from elv_unregister(),
2620 * so no more cic's are allowed to be linked into this ioc. So it 2625 * so no more cic's are allowed to be linked into this ioc. So it
2621 * should be ok to iterate over the known list, we will see all cic's 2626 * should be ok to iterate over the known list, we will see all cic's
2622 * since no new ones are added. 2627 * since no new ones are added.
2623 */ 2628 */
2624 __call_for_each_cic(ioc, cic_free_func); 2629 __call_for_each_cic(ioc, cic_free_func);
2625 } 2630 }
2626 2631
2627 static void cfq_put_cooperator(struct cfq_queue *cfqq) 2632 static void cfq_put_cooperator(struct cfq_queue *cfqq)
2628 { 2633 {
2629 struct cfq_queue *__cfqq, *next; 2634 struct cfq_queue *__cfqq, *next;
2630 2635
2631 /* 2636 /*
2632 * If this queue was scheduled to merge with another queue, be 2637 * If this queue was scheduled to merge with another queue, be
2633 * sure to drop the reference taken on that queue (and others in 2638 * sure to drop the reference taken on that queue (and others in
2634 * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. 2639 * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs.
2635 */ 2640 */
2636 __cfqq = cfqq->new_cfqq; 2641 __cfqq = cfqq->new_cfqq;
2637 while (__cfqq) { 2642 while (__cfqq) {
2638 if (__cfqq == cfqq) { 2643 if (__cfqq == cfqq) {
2639 WARN(1, "cfqq->new_cfqq loop detected\n"); 2644 WARN(1, "cfqq->new_cfqq loop detected\n");
2640 break; 2645 break;
2641 } 2646 }
2642 next = __cfqq->new_cfqq; 2647 next = __cfqq->new_cfqq;
2643 cfq_put_queue(__cfqq); 2648 cfq_put_queue(__cfqq);
2644 __cfqq = next; 2649 __cfqq = next;
2645 } 2650 }
2646 } 2651 }
2647 2652
2648 static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) 2653 static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
2649 { 2654 {
2650 if (unlikely(cfqq == cfqd->active_queue)) { 2655 if (unlikely(cfqq == cfqd->active_queue)) {
2651 __cfq_slice_expired(cfqd, cfqq, 0); 2656 __cfq_slice_expired(cfqd, cfqq, 0);
2652 cfq_schedule_dispatch(cfqd); 2657 cfq_schedule_dispatch(cfqd);
2653 } 2658 }
2654 2659
2655 cfq_put_cooperator(cfqq); 2660 cfq_put_cooperator(cfqq);
2656 2661
2657 cfq_put_queue(cfqq); 2662 cfq_put_queue(cfqq);
2658 } 2663 }
2659 2664
2660 static void __cfq_exit_single_io_context(struct cfq_data *cfqd, 2665 static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
2661 struct cfq_io_context *cic) 2666 struct cfq_io_context *cic)
2662 { 2667 {
2663 struct io_context *ioc = cic->ioc; 2668 struct io_context *ioc = cic->ioc;
2664 2669
2665 list_del_init(&cic->queue_list); 2670 list_del_init(&cic->queue_list);
2666 2671
2667 /* 2672 /*
2668 * Make sure dead mark is seen for dead queues 2673 * Make sure dead mark is seen for dead queues
2669 */ 2674 */
2670 smp_wmb(); 2675 smp_wmb();
2671 cic->key = cfqd_dead_key(cfqd); 2676 cic->key = cfqd_dead_key(cfqd);
2672 2677
2673 if (ioc->ioc_data == cic) 2678 if (ioc->ioc_data == cic)
2674 rcu_assign_pointer(ioc->ioc_data, NULL); 2679 rcu_assign_pointer(ioc->ioc_data, NULL);
2675 2680
2676 if (cic->cfqq[BLK_RW_ASYNC]) { 2681 if (cic->cfqq[BLK_RW_ASYNC]) {
2677 cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]); 2682 cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]);
2678 cic->cfqq[BLK_RW_ASYNC] = NULL; 2683 cic->cfqq[BLK_RW_ASYNC] = NULL;
2679 } 2684 }
2680 2685
2681 if (cic->cfqq[BLK_RW_SYNC]) { 2686 if (cic->cfqq[BLK_RW_SYNC]) {
2682 cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]); 2687 cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]);
2683 cic->cfqq[BLK_RW_SYNC] = NULL; 2688 cic->cfqq[BLK_RW_SYNC] = NULL;
2684 } 2689 }
2685 } 2690 }
2686 2691
2687 static void cfq_exit_single_io_context(struct io_context *ioc, 2692 static void cfq_exit_single_io_context(struct io_context *ioc,
2688 struct cfq_io_context *cic) 2693 struct cfq_io_context *cic)
2689 { 2694 {
2690 struct cfq_data *cfqd = cic_to_cfqd(cic); 2695 struct cfq_data *cfqd = cic_to_cfqd(cic);
2691 2696
2692 if (cfqd) { 2697 if (cfqd) {
2693 struct request_queue *q = cfqd->queue; 2698 struct request_queue *q = cfqd->queue;
2694 unsigned long flags; 2699 unsigned long flags;
2695 2700
2696 spin_lock_irqsave(q->queue_lock, flags); 2701 spin_lock_irqsave(q->queue_lock, flags);
2697 2702
2698 /* 2703 /*
2699 * Ensure we get a fresh copy of the ->key to prevent 2704 * Ensure we get a fresh copy of the ->key to prevent
2700 * race between exiting task and queue 2705 * race between exiting task and queue
2701 */ 2706 */
2702 smp_read_barrier_depends(); 2707 smp_read_barrier_depends();
2703 if (cic->key == cfqd) 2708 if (cic->key == cfqd)
2704 __cfq_exit_single_io_context(cfqd, cic); 2709 __cfq_exit_single_io_context(cfqd, cic);
2705 2710
2706 spin_unlock_irqrestore(q->queue_lock, flags); 2711 spin_unlock_irqrestore(q->queue_lock, flags);
2707 } 2712 }
2708 } 2713 }
2709 2714
2710 /* 2715 /*
2711 * The process that ioc belongs to has exited, we need to clean up 2716 * The process that ioc belongs to has exited, we need to clean up
2712 * and put the internal structures we have that belongs to that process. 2717 * and put the internal structures we have that belongs to that process.
2713 */ 2718 */
2714 static void cfq_exit_io_context(struct io_context *ioc) 2719 static void cfq_exit_io_context(struct io_context *ioc)
2715 { 2720 {
2716 call_for_each_cic(ioc, cfq_exit_single_io_context); 2721 call_for_each_cic(ioc, cfq_exit_single_io_context);
2717 } 2722 }
2718 2723
2719 static struct cfq_io_context * 2724 static struct cfq_io_context *
2720 cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) 2725 cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
2721 { 2726 {
2722 struct cfq_io_context *cic; 2727 struct cfq_io_context *cic;
2723 2728
2724 cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO, 2729 cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO,
2725 cfqd->queue->node); 2730 cfqd->queue->node);
2726 if (cic) { 2731 if (cic) {
2727 cic->last_end_request = jiffies; 2732 cic->last_end_request = jiffies;
2728 INIT_LIST_HEAD(&cic->queue_list); 2733 INIT_LIST_HEAD(&cic->queue_list);
2729 INIT_HLIST_NODE(&cic->cic_list); 2734 INIT_HLIST_NODE(&cic->cic_list);
2730 cic->dtor = cfq_free_io_context; 2735 cic->dtor = cfq_free_io_context;
2731 cic->exit = cfq_exit_io_context; 2736 cic->exit = cfq_exit_io_context;
2732 elv_ioc_count_inc(cfq_ioc_count); 2737 elv_ioc_count_inc(cfq_ioc_count);
2733 } 2738 }
2734 2739
2735 return cic; 2740 return cic;
2736 } 2741 }
2737 2742
2738 static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc) 2743 static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)
2739 { 2744 {
2740 struct task_struct *tsk = current; 2745 struct task_struct *tsk = current;
2741 int ioprio_class; 2746 int ioprio_class;
2742 2747
2743 if (!cfq_cfqq_prio_changed(cfqq)) 2748 if (!cfq_cfqq_prio_changed(cfqq))
2744 return; 2749 return;
2745 2750
2746 ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); 2751 ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio);
2747 switch (ioprio_class) { 2752 switch (ioprio_class) {
2748 default: 2753 default:
2749 printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); 2754 printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
2750 case IOPRIO_CLASS_NONE: 2755 case IOPRIO_CLASS_NONE:
2751 /* 2756 /*
2752 * no prio set, inherit CPU scheduling settings 2757 * no prio set, inherit CPU scheduling settings
2753 */ 2758 */
2754 cfqq->ioprio = task_nice_ioprio(tsk); 2759 cfqq->ioprio = task_nice_ioprio(tsk);
2755 cfqq->ioprio_class = task_nice_ioclass(tsk); 2760 cfqq->ioprio_class = task_nice_ioclass(tsk);
2756 break; 2761 break;
2757 case IOPRIO_CLASS_RT: 2762 case IOPRIO_CLASS_RT:
2758 cfqq->ioprio = task_ioprio(ioc); 2763 cfqq->ioprio = task_ioprio(ioc);
2759 cfqq->ioprio_class = IOPRIO_CLASS_RT; 2764 cfqq->ioprio_class = IOPRIO_CLASS_RT;
2760 break; 2765 break;
2761 case IOPRIO_CLASS_BE: 2766 case IOPRIO_CLASS_BE:
2762 cfqq->ioprio = task_ioprio(ioc); 2767 cfqq->ioprio = task_ioprio(ioc);
2763 cfqq->ioprio_class = IOPRIO_CLASS_BE; 2768 cfqq->ioprio_class = IOPRIO_CLASS_BE;
2764 break; 2769 break;
2765 case IOPRIO_CLASS_IDLE: 2770 case IOPRIO_CLASS_IDLE:
2766 cfqq->ioprio_class = IOPRIO_CLASS_IDLE; 2771 cfqq->ioprio_class = IOPRIO_CLASS_IDLE;
2767 cfqq->ioprio = 7; 2772 cfqq->ioprio = 7;
2768 cfq_clear_cfqq_idle_window(cfqq); 2773 cfq_clear_cfqq_idle_window(cfqq);
2769 break; 2774 break;
2770 } 2775 }
2771 2776
2772 /* 2777 /*
2773 * keep track of original prio settings in case we have to temporarily 2778 * keep track of original prio settings in case we have to temporarily
2774 * elevate the priority of this queue 2779 * elevate the priority of this queue
2775 */ 2780 */
2776 cfqq->org_ioprio = cfqq->ioprio; 2781 cfqq->org_ioprio = cfqq->ioprio;
2777 cfqq->org_ioprio_class = cfqq->ioprio_class; 2782 cfqq->org_ioprio_class = cfqq->ioprio_class;
2778 cfq_clear_cfqq_prio_changed(cfqq); 2783 cfq_clear_cfqq_prio_changed(cfqq);
2779 } 2784 }
2780 2785
2781 static void changed_ioprio(struct io_context *ioc, struct cfq_io_context *cic) 2786 static void changed_ioprio(struct io_context *ioc, struct cfq_io_context *cic)
2782 { 2787 {
2783 struct cfq_data *cfqd = cic_to_cfqd(cic); 2788 struct cfq_data *cfqd = cic_to_cfqd(cic);
2784 struct cfq_queue *cfqq; 2789 struct cfq_queue *cfqq;
2785 unsigned long flags; 2790 unsigned long flags;
2786 2791
2787 if (unlikely(!cfqd)) 2792 if (unlikely(!cfqd))
2788 return; 2793 return;
2789 2794
2790 spin_lock_irqsave(cfqd->queue->queue_lock, flags); 2795 spin_lock_irqsave(cfqd->queue->queue_lock, flags);
2791 2796
2792 cfqq = cic->cfqq[BLK_RW_ASYNC]; 2797 cfqq = cic->cfqq[BLK_RW_ASYNC];
2793 if (cfqq) { 2798 if (cfqq) {
2794 struct cfq_queue *new_cfqq; 2799 struct cfq_queue *new_cfqq;
2795 new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->ioc, 2800 new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->ioc,
2796 GFP_ATOMIC); 2801 GFP_ATOMIC);
2797 if (new_cfqq) { 2802 if (new_cfqq) {
2798 cic->cfqq[BLK_RW_ASYNC] = new_cfqq; 2803 cic->cfqq[BLK_RW_ASYNC] = new_cfqq;
2799 cfq_put_queue(cfqq); 2804 cfq_put_queue(cfqq);
2800 } 2805 }
2801 } 2806 }
2802 2807
2803 cfqq = cic->cfqq[BLK_RW_SYNC]; 2808 cfqq = cic->cfqq[BLK_RW_SYNC];
2804 if (cfqq) 2809 if (cfqq)
2805 cfq_mark_cfqq_prio_changed(cfqq); 2810 cfq_mark_cfqq_prio_changed(cfqq);
2806 2811
2807 spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); 2812 spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
2808 } 2813 }
2809 2814
2810 static void cfq_ioc_set_ioprio(struct io_context *ioc) 2815 static void cfq_ioc_set_ioprio(struct io_context *ioc)
2811 { 2816 {
2812 call_for_each_cic(ioc, changed_ioprio); 2817 call_for_each_cic(ioc, changed_ioprio);
2813 ioc->ioprio_changed = 0; 2818 ioc->ioprio_changed = 0;
2814 } 2819 }
2815 2820
2816 static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, 2821 static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
2817 pid_t pid, bool is_sync) 2822 pid_t pid, bool is_sync)
2818 { 2823 {
2819 RB_CLEAR_NODE(&cfqq->rb_node); 2824 RB_CLEAR_NODE(&cfqq->rb_node);
2820 RB_CLEAR_NODE(&cfqq->p_node); 2825 RB_CLEAR_NODE(&cfqq->p_node);
2821 INIT_LIST_HEAD(&cfqq->fifo); 2826 INIT_LIST_HEAD(&cfqq->fifo);
2822 2827
2823 atomic_set(&cfqq->ref, 0); 2828 atomic_set(&cfqq->ref, 0);
2824 cfqq->cfqd = cfqd; 2829 cfqq->cfqd = cfqd;
2825 2830
2826 cfq_mark_cfqq_prio_changed(cfqq); 2831 cfq_mark_cfqq_prio_changed(cfqq);
2827 2832
2828 if (is_sync) { 2833 if (is_sync) {
2829 if (!cfq_class_idle(cfqq)) 2834 if (!cfq_class_idle(cfqq))
2830 cfq_mark_cfqq_idle_window(cfqq); 2835 cfq_mark_cfqq_idle_window(cfqq);
2831 cfq_mark_cfqq_sync(cfqq); 2836 cfq_mark_cfqq_sync(cfqq);
2832 } 2837 }
2833 cfqq->pid = pid; 2838 cfqq->pid = pid;
2834 } 2839 }
2835 2840
2836 #ifdef CONFIG_CFQ_GROUP_IOSCHED 2841 #ifdef CONFIG_CFQ_GROUP_IOSCHED
2837 static void changed_cgroup(struct io_context *ioc, struct cfq_io_context *cic) 2842 static void changed_cgroup(struct io_context *ioc, struct cfq_io_context *cic)
2838 { 2843 {
2839 struct cfq_queue *sync_cfqq = cic_to_cfqq(cic, 1); 2844 struct cfq_queue *sync_cfqq = cic_to_cfqq(cic, 1);
2840 struct cfq_data *cfqd = cic_to_cfqd(cic); 2845 struct cfq_data *cfqd = cic_to_cfqd(cic);
2841 unsigned long flags; 2846 unsigned long flags;
2842 struct request_queue *q; 2847 struct request_queue *q;
2843 2848
2844 if (unlikely(!cfqd)) 2849 if (unlikely(!cfqd))
2845 return; 2850 return;
2846 2851
2847 q = cfqd->queue; 2852 q = cfqd->queue;
2848 2853
2849 spin_lock_irqsave(q->queue_lock, flags); 2854 spin_lock_irqsave(q->queue_lock, flags);
2850 2855
2851 if (sync_cfqq) { 2856 if (sync_cfqq) {
2852 /* 2857 /*
2853 * Drop reference to sync queue. A new sync queue will be 2858 * Drop reference to sync queue. A new sync queue will be
2854 * assigned in new group upon arrival of a fresh request. 2859 * assigned in new group upon arrival of a fresh request.
2855 */ 2860 */
2856 cfq_log_cfqq(cfqd, sync_cfqq, "changed cgroup"); 2861 cfq_log_cfqq(cfqd, sync_cfqq, "changed cgroup");
2857 cic_set_cfqq(cic, NULL, 1); 2862 cic_set_cfqq(cic, NULL, 1);
2858 cfq_put_queue(sync_cfqq); 2863 cfq_put_queue(sync_cfqq);
2859 } 2864 }
2860 2865
2861 spin_unlock_irqrestore(q->queue_lock, flags); 2866 spin_unlock_irqrestore(q->queue_lock, flags);
2862 } 2867 }
2863 2868
2864 static void cfq_ioc_set_cgroup(struct io_context *ioc) 2869 static void cfq_ioc_set_cgroup(struct io_context *ioc)
2865 { 2870 {
2866 call_for_each_cic(ioc, changed_cgroup); 2871 call_for_each_cic(ioc, changed_cgroup);
2867 ioc->cgroup_changed = 0; 2872 ioc->cgroup_changed = 0;
2868 } 2873 }
2869 #endif /* CONFIG_CFQ_GROUP_IOSCHED */ 2874 #endif /* CONFIG_CFQ_GROUP_IOSCHED */
2870 2875
2871 static struct cfq_queue * 2876 static struct cfq_queue *
2872 cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, 2877 cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync,
2873 struct io_context *ioc, gfp_t gfp_mask) 2878 struct io_context *ioc, gfp_t gfp_mask)
2874 { 2879 {
2875 struct cfq_queue *cfqq, *new_cfqq = NULL; 2880 struct cfq_queue *cfqq, *new_cfqq = NULL;
2876 struct cfq_io_context *cic; 2881 struct cfq_io_context *cic;
2877 struct cfq_group *cfqg; 2882 struct cfq_group *cfqg;
2878 2883
2879 retry: 2884 retry:
2880 cfqg = cfq_get_cfqg(cfqd, 1); 2885 cfqg = cfq_get_cfqg(cfqd, 1);
2881 cic = cfq_cic_lookup(cfqd, ioc); 2886 cic = cfq_cic_lookup(cfqd, ioc);
2882 /* cic always exists here */ 2887 /* cic always exists here */
2883 cfqq = cic_to_cfqq(cic, is_sync); 2888 cfqq = cic_to_cfqq(cic, is_sync);
2884 2889
2885 /* 2890 /*
2886 * Always try a new alloc if we fell back to the OOM cfqq 2891 * Always try a new alloc if we fell back to the OOM cfqq
2887 * originally, since it should just be a temporary situation. 2892 * originally, since it should just be a temporary situation.
2888 */ 2893 */
2889 if (!cfqq || cfqq == &cfqd->oom_cfqq) { 2894 if (!cfqq || cfqq == &cfqd->oom_cfqq) {
2890 cfqq = NULL; 2895 cfqq = NULL;
2891 if (new_cfqq) { 2896 if (new_cfqq) {
2892 cfqq = new_cfqq; 2897 cfqq = new_cfqq;
2893 new_cfqq = NULL; 2898 new_cfqq = NULL;
2894 } else if (gfp_mask & __GFP_WAIT) { 2899 } else if (gfp_mask & __GFP_WAIT) {
2895 spin_unlock_irq(cfqd->queue->queue_lock); 2900 spin_unlock_irq(cfqd->queue->queue_lock);
2896 new_cfqq = kmem_cache_alloc_node(cfq_pool, 2901 new_cfqq = kmem_cache_alloc_node(cfq_pool,
2897 gfp_mask | __GFP_ZERO, 2902 gfp_mask | __GFP_ZERO,
2898 cfqd->queue->node); 2903 cfqd->queue->node);
2899 spin_lock_irq(cfqd->queue->queue_lock); 2904 spin_lock_irq(cfqd->queue->queue_lock);
2900 if (new_cfqq) 2905 if (new_cfqq)
2901 goto retry; 2906 goto retry;
2902 } else { 2907 } else {
2903 cfqq = kmem_cache_alloc_node(cfq_pool, 2908 cfqq = kmem_cache_alloc_node(cfq_pool,
2904 gfp_mask | __GFP_ZERO, 2909 gfp_mask | __GFP_ZERO,
2905 cfqd->queue->node); 2910 cfqd->queue->node);
2906 } 2911 }
2907 2912
2908 if (cfqq) { 2913 if (cfqq) {
2909 cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); 2914 cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync);
2910 cfq_init_prio_data(cfqq, ioc); 2915 cfq_init_prio_data(cfqq, ioc);
2911 cfq_link_cfqq_cfqg(cfqq, cfqg); 2916 cfq_link_cfqq_cfqg(cfqq, cfqg);
2912 cfq_log_cfqq(cfqd, cfqq, "alloced"); 2917 cfq_log_cfqq(cfqd, cfqq, "alloced");
2913 } else 2918 } else
2914 cfqq = &cfqd->oom_cfqq; 2919 cfqq = &cfqd->oom_cfqq;
2915 } 2920 }
2916 2921
2917 if (new_cfqq) 2922 if (new_cfqq)
2918 kmem_cache_free(cfq_pool, new_cfqq); 2923 kmem_cache_free(cfq_pool, new_cfqq);
2919 2924
2920 return cfqq; 2925 return cfqq;
2921 } 2926 }
2922 2927
2923 static struct cfq_queue ** 2928 static struct cfq_queue **
2924 cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) 2929 cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio)
2925 { 2930 {
2926 switch (ioprio_class) { 2931 switch (ioprio_class) {
2927 case IOPRIO_CLASS_RT: 2932 case IOPRIO_CLASS_RT:
2928 return &cfqd->async_cfqq[0][ioprio]; 2933 return &cfqd->async_cfqq[0][ioprio];
2929 case IOPRIO_CLASS_BE: 2934 case IOPRIO_CLASS_BE:
2930 return &cfqd->async_cfqq[1][ioprio]; 2935 return &cfqd->async_cfqq[1][ioprio];
2931 case IOPRIO_CLASS_IDLE: 2936 case IOPRIO_CLASS_IDLE:
2932 return &cfqd->async_idle_cfqq; 2937 return &cfqd->async_idle_cfqq;
2933 default: 2938 default:
2934 BUG(); 2939 BUG();
2935 } 2940 }
2936 } 2941 }
2937 2942
2938 static struct cfq_queue * 2943 static struct cfq_queue *
2939 cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, 2944 cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc,
2940 gfp_t gfp_mask) 2945 gfp_t gfp_mask)
2941 { 2946 {
2942 const int ioprio = task_ioprio(ioc); 2947 const int ioprio = task_ioprio(ioc);
2943 const int ioprio_class = task_ioprio_class(ioc); 2948 const int ioprio_class = task_ioprio_class(ioc);
2944 struct cfq_queue **async_cfqq = NULL; 2949 struct cfq_queue **async_cfqq = NULL;
2945 struct cfq_queue *cfqq = NULL; 2950 struct cfq_queue *cfqq = NULL;
2946 2951
2947 if (!is_sync) { 2952 if (!is_sync) {
2948 async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); 2953 async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio);
2949 cfqq = *async_cfqq; 2954 cfqq = *async_cfqq;
2950 } 2955 }
2951 2956
2952 if (!cfqq) 2957 if (!cfqq)
2953 cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask); 2958 cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask);
2954 2959
2955 /* 2960 /*
2956 * pin the queue now that it's allocated, scheduler exit will prune it 2961 * pin the queue now that it's allocated, scheduler exit will prune it
2957 */ 2962 */
2958 if (!is_sync && !(*async_cfqq)) { 2963 if (!is_sync && !(*async_cfqq)) {
2959 atomic_inc(&cfqq->ref); 2964 atomic_inc(&cfqq->ref);
2960 *async_cfqq = cfqq; 2965 *async_cfqq = cfqq;
2961 } 2966 }
2962 2967
2963 atomic_inc(&cfqq->ref); 2968 atomic_inc(&cfqq->ref);
2964 return cfqq; 2969 return cfqq;
2965 } 2970 }
2966 2971
2967 /* 2972 /*
2968 * We drop cfq io contexts lazily, so we may find a dead one. 2973 * We drop cfq io contexts lazily, so we may find a dead one.
2969 */ 2974 */
2970 static void 2975 static void
2971 cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc, 2976 cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc,
2972 struct cfq_io_context *cic) 2977 struct cfq_io_context *cic)
2973 { 2978 {
2974 unsigned long flags; 2979 unsigned long flags;
2975 2980
2976 WARN_ON(!list_empty(&cic->queue_list)); 2981 WARN_ON(!list_empty(&cic->queue_list));
2977 BUG_ON(cic->key != cfqd_dead_key(cfqd)); 2982 BUG_ON(cic->key != cfqd_dead_key(cfqd));
2978 2983
2979 spin_lock_irqsave(&ioc->lock, flags); 2984 spin_lock_irqsave(&ioc->lock, flags);
2980 2985
2981 BUG_ON(ioc->ioc_data == cic); 2986 BUG_ON(ioc->ioc_data == cic);
2982 2987
2983 radix_tree_delete(&ioc->radix_root, cfqd->cic_index); 2988 radix_tree_delete(&ioc->radix_root, cfqd->cic_index);
2984 hlist_del_rcu(&cic->cic_list); 2989 hlist_del_rcu(&cic->cic_list);
2985 spin_unlock_irqrestore(&ioc->lock, flags); 2990 spin_unlock_irqrestore(&ioc->lock, flags);
2986 2991
2987 cfq_cic_free(cic); 2992 cfq_cic_free(cic);
2988 } 2993 }
2989 2994
2990 static struct cfq_io_context * 2995 static struct cfq_io_context *
2991 cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) 2996 cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc)
2992 { 2997 {
2993 struct cfq_io_context *cic; 2998 struct cfq_io_context *cic;
2994 unsigned long flags; 2999 unsigned long flags;
2995 3000
2996 if (unlikely(!ioc)) 3001 if (unlikely(!ioc))
2997 return NULL; 3002 return NULL;
2998 3003
2999 rcu_read_lock(); 3004 rcu_read_lock();
3000 3005
3001 /* 3006 /*
3002 * we maintain a last-hit cache, to avoid browsing over the tree 3007 * we maintain a last-hit cache, to avoid browsing over the tree
3003 */ 3008 */
3004 cic = rcu_dereference(ioc->ioc_data); 3009 cic = rcu_dereference(ioc->ioc_data);
3005 if (cic && cic->key == cfqd) { 3010 if (cic && cic->key == cfqd) {
3006 rcu_read_unlock(); 3011 rcu_read_unlock();
3007 return cic; 3012 return cic;
3008 } 3013 }
3009 3014
3010 do { 3015 do {
3011 cic = radix_tree_lookup(&ioc->radix_root, cfqd->cic_index); 3016 cic = radix_tree_lookup(&ioc->radix_root, cfqd->cic_index);
3012 rcu_read_unlock(); 3017 rcu_read_unlock();
3013 if (!cic) 3018 if (!cic)
3014 break; 3019 break;
3015 if (unlikely(cic->key != cfqd)) { 3020 if (unlikely(cic->key != cfqd)) {
3016 cfq_drop_dead_cic(cfqd, ioc, cic); 3021 cfq_drop_dead_cic(cfqd, ioc, cic);
3017 rcu_read_lock(); 3022 rcu_read_lock();
3018 continue; 3023 continue;
3019 } 3024 }
3020 3025
3021 spin_lock_irqsave(&ioc->lock, flags); 3026 spin_lock_irqsave(&ioc->lock, flags);
3022 rcu_assign_pointer(ioc->ioc_data, cic); 3027 rcu_assign_pointer(ioc->ioc_data, cic);
3023 spin_unlock_irqrestore(&ioc->lock, flags); 3028 spin_unlock_irqrestore(&ioc->lock, flags);
3024 break; 3029 break;
3025 } while (1); 3030 } while (1);
3026 3031
3027 return cic; 3032 return cic;
3028 } 3033 }
3029 3034
3030 /* 3035 /*
3031 * Add cic into ioc, using cfqd as the search key. This enables us to lookup 3036 * Add cic into ioc, using cfqd as the search key. This enables us to lookup
3032 * the process specific cfq io context when entered from the block layer. 3037 * the process specific cfq io context when entered from the block layer.
3033 * Also adds the cic to a per-cfqd list, used when this queue is removed. 3038 * Also adds the cic to a per-cfqd list, used when this queue is removed.
3034 */ 3039 */
3035 static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, 3040 static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc,
3036 struct cfq_io_context *cic, gfp_t gfp_mask) 3041 struct cfq_io_context *cic, gfp_t gfp_mask)
3037 { 3042 {
3038 unsigned long flags; 3043 unsigned long flags;
3039 int ret; 3044 int ret;
3040 3045
3041 ret = radix_tree_preload(gfp_mask); 3046 ret = radix_tree_preload(gfp_mask);
3042 if (!ret) { 3047 if (!ret) {
3043 cic->ioc = ioc; 3048 cic->ioc = ioc;
3044 cic->key = cfqd; 3049 cic->key = cfqd;
3045 3050
3046 spin_lock_irqsave(&ioc->lock, flags); 3051 spin_lock_irqsave(&ioc->lock, flags);
3047 ret = radix_tree_insert(&ioc->radix_root, 3052 ret = radix_tree_insert(&ioc->radix_root,
3048 cfqd->cic_index, cic); 3053 cfqd->cic_index, cic);
3049 if (!ret) 3054 if (!ret)
3050 hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list); 3055 hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list);
3051 spin_unlock_irqrestore(&ioc->lock, flags); 3056 spin_unlock_irqrestore(&ioc->lock, flags);
3052 3057
3053 radix_tree_preload_end(); 3058 radix_tree_preload_end();
3054 3059
3055 if (!ret) { 3060 if (!ret) {
3056 spin_lock_irqsave(cfqd->queue->queue_lock, flags); 3061 spin_lock_irqsave(cfqd->queue->queue_lock, flags);
3057 list_add(&cic->queue_list, &cfqd->cic_list); 3062 list_add(&cic->queue_list, &cfqd->cic_list);
3058 spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); 3063 spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
3059 } 3064 }
3060 } 3065 }
3061 3066
3062 if (ret) 3067 if (ret)
3063 printk(KERN_ERR "cfq: cic link failed!\n"); 3068 printk(KERN_ERR "cfq: cic link failed!\n");
3064 3069
3065 return ret; 3070 return ret;
3066 } 3071 }
3067 3072
3068 /* 3073 /*
3069 * Setup general io context and cfq io context. There can be several cfq 3074 * Setup general io context and cfq io context. There can be several cfq
3070 * io contexts per general io context, if this process is doing io to more 3075 * io contexts per general io context, if this process is doing io to more
3071 * than one device managed by cfq. 3076 * than one device managed by cfq.
3072 */ 3077 */
3073 static struct cfq_io_context * 3078 static struct cfq_io_context *
3074 cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) 3079 cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
3075 { 3080 {
3076 struct io_context *ioc = NULL; 3081 struct io_context *ioc = NULL;
3077 struct cfq_io_context *cic; 3082 struct cfq_io_context *cic;
3078 3083
3079 might_sleep_if(gfp_mask & __GFP_WAIT); 3084 might_sleep_if(gfp_mask & __GFP_WAIT);
3080 3085
3081 ioc = get_io_context(gfp_mask, cfqd->queue->node); 3086 ioc = get_io_context(gfp_mask, cfqd->queue->node);
3082 if (!ioc) 3087 if (!ioc)
3083 return NULL; 3088 return NULL;
3084 3089
3085 cic = cfq_cic_lookup(cfqd, ioc); 3090 cic = cfq_cic_lookup(cfqd, ioc);
3086 if (cic) 3091 if (cic)
3087 goto out; 3092 goto out;
3088 3093
3089 cic = cfq_alloc_io_context(cfqd, gfp_mask); 3094 cic = cfq_alloc_io_context(cfqd, gfp_mask);
3090 if (cic == NULL) 3095 if (cic == NULL)
3091 goto err; 3096 goto err;
3092 3097
3093 if (cfq_cic_link(cfqd, ioc, cic, gfp_mask)) 3098 if (cfq_cic_link(cfqd, ioc, cic, gfp_mask))
3094 goto err_free; 3099 goto err_free;
3095 3100
3096 out: 3101 out:
3097 smp_read_barrier_depends(); 3102 smp_read_barrier_depends();
3098 if (unlikely(ioc->ioprio_changed)) 3103 if (unlikely(ioc->ioprio_changed))
3099 cfq_ioc_set_ioprio(ioc); 3104 cfq_ioc_set_ioprio(ioc);
3100 3105
3101 #ifdef CONFIG_CFQ_GROUP_IOSCHED 3106 #ifdef CONFIG_CFQ_GROUP_IOSCHED
3102 if (unlikely(ioc->cgroup_changed)) 3107 if (unlikely(ioc->cgroup_changed))
3103 cfq_ioc_set_cgroup(ioc); 3108 cfq_ioc_set_cgroup(ioc);
3104 #endif 3109 #endif
3105 return cic; 3110 return cic;
3106 err_free: 3111 err_free:
3107 cfq_cic_free(cic); 3112 cfq_cic_free(cic);
3108 err: 3113 err:
3109 put_io_context(ioc); 3114 put_io_context(ioc);
3110 return NULL; 3115 return NULL;
3111 } 3116 }
3112 3117
3113 static void 3118 static void
3114 cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) 3119 cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic)
3115 { 3120 {
3116 unsigned long elapsed = jiffies - cic->last_end_request; 3121 unsigned long elapsed = jiffies - cic->last_end_request;
3117 unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle); 3122 unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle);
3118 3123
3119 cic->ttime_samples = (7*cic->ttime_samples + 256) / 8; 3124 cic->ttime_samples = (7*cic->ttime_samples + 256) / 8;
3120 cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8; 3125 cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8;
3121 cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples; 3126 cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples;
3122 } 3127 }
3123 3128
3124 static void 3129 static void
3125 cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, 3130 cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq,
3126 struct request *rq) 3131 struct request *rq)
3127 { 3132 {
3128 sector_t sdist = 0; 3133 sector_t sdist = 0;
3129 sector_t n_sec = blk_rq_sectors(rq); 3134 sector_t n_sec = blk_rq_sectors(rq);
3130 if (cfqq->last_request_pos) { 3135 if (cfqq->last_request_pos) {
3131 if (cfqq->last_request_pos < blk_rq_pos(rq)) 3136 if (cfqq->last_request_pos < blk_rq_pos(rq))
3132 sdist = blk_rq_pos(rq) - cfqq->last_request_pos; 3137 sdist = blk_rq_pos(rq) - cfqq->last_request_pos;
3133 else 3138 else
3134 sdist = cfqq->last_request_pos - blk_rq_pos(rq); 3139 sdist = cfqq->last_request_pos - blk_rq_pos(rq);
3135 } 3140 }
3136 3141
3137 cfqq->seek_history <<= 1; 3142 cfqq->seek_history <<= 1;
3138 if (blk_queue_nonrot(cfqd->queue)) 3143 if (blk_queue_nonrot(cfqd->queue))
3139 cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT); 3144 cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT);
3140 else 3145 else
3141 cfqq->seek_history |= (sdist > CFQQ_SEEK_THR); 3146 cfqq->seek_history |= (sdist > CFQQ_SEEK_THR);
3142 } 3147 }
3143 3148
3144 /* 3149 /*
3145 * Disable idle window if the process thinks too long or seeks so much that 3150 * Disable idle window if the process thinks too long or seeks so much that
3146 * it doesn't matter 3151 * it doesn't matter
3147 */ 3152 */
3148 static void 3153 static void
3149 cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, 3154 cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
3150 struct cfq_io_context *cic) 3155 struct cfq_io_context *cic)
3151 { 3156 {
3152 int old_idle, enable_idle; 3157 int old_idle, enable_idle;
3153 3158
3154 /* 3159 /*
3155 * Don't idle for async or idle io prio class 3160 * Don't idle for async or idle io prio class
3156 */ 3161 */
3157 if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) 3162 if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq))
3158 return; 3163 return;
3159 3164
3160 enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); 3165 enable_idle = old_idle = cfq_cfqq_idle_window(cfqq);
3161 3166
3162 if (cfqq->queued[0] + cfqq->queued[1] >= 4) 3167 if (cfqq->queued[0] + cfqq->queued[1] >= 4)
3163 cfq_mark_cfqq_deep(cfqq); 3168 cfq_mark_cfqq_deep(cfqq);
3164 3169
3165 if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || 3170 if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle ||
3166 (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq))) 3171 (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq)))
3167 enable_idle = 0; 3172 enable_idle = 0;
3168 else if (sample_valid(cic->ttime_samples)) { 3173 else if (sample_valid(cic->ttime_samples)) {
3169 if (cic->ttime_mean > cfqd->cfq_slice_idle) 3174 if (cic->ttime_mean > cfqd->cfq_slice_idle)
3170 enable_idle = 0; 3175 enable_idle = 0;
3171 else 3176 else
3172 enable_idle = 1; 3177 enable_idle = 1;
3173 } 3178 }
3174 3179
3175 if (old_idle != enable_idle) { 3180 if (old_idle != enable_idle) {
3176 cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); 3181 cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle);
3177 if (enable_idle) 3182 if (enable_idle)
3178 cfq_mark_cfqq_idle_window(cfqq); 3183 cfq_mark_cfqq_idle_window(cfqq);
3179 else 3184 else
3180 cfq_clear_cfqq_idle_window(cfqq); 3185 cfq_clear_cfqq_idle_window(cfqq);
3181 } 3186 }
3182 } 3187 }
3183 3188
3184 /* 3189 /*
3185 * Check if new_cfqq should preempt the currently active queue. Return 0 for 3190 * Check if new_cfqq should preempt the currently active queue. Return 0 for
3186 * no or if we aren't sure, a 1 will cause a preempt. 3191 * no or if we aren't sure, a 1 will cause a preempt.
3187 */ 3192 */
3188 static bool 3193 static bool
3189 cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, 3194 cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
3190 struct request *rq) 3195 struct request *rq)
3191 { 3196 {
3192 struct cfq_queue *cfqq; 3197 struct cfq_queue *cfqq;
3193 3198
3194 cfqq = cfqd->active_queue; 3199 cfqq = cfqd->active_queue;
3195 if (!cfqq) 3200 if (!cfqq)
3196 return false; 3201 return false;
3197 3202
3198 if (cfq_class_idle(new_cfqq)) 3203 if (cfq_class_idle(new_cfqq))
3199 return false; 3204 return false;
3200 3205
3201 if (cfq_class_idle(cfqq)) 3206 if (cfq_class_idle(cfqq))
3202 return true; 3207 return true;
3203 3208
3204 /* 3209 /*
3205 * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice. 3210 * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice.
3206 */ 3211 */
3207 if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq)) 3212 if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq))
3208 return false; 3213 return false;
3209 3214
3210 /* 3215 /*
3211 * if the new request is sync, but the currently running queue is 3216 * if the new request is sync, but the currently running queue is
3212 * not, let the sync request have priority. 3217 * not, let the sync request have priority.
3213 */ 3218 */
3214 if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) 3219 if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq))
3215 return true; 3220 return true;
3216 3221
3217 if (new_cfqq->cfqg != cfqq->cfqg) 3222 if (new_cfqq->cfqg != cfqq->cfqg)
3218 return false; 3223 return false;
3219 3224
3220 if (cfq_slice_used(cfqq)) 3225 if (cfq_slice_used(cfqq))
3221 return true; 3226 return true;
3222 3227
3223 /* Allow preemption only if we are idling on sync-noidle tree */ 3228 /* Allow preemption only if we are idling on sync-noidle tree */
3224 if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD && 3229 if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD &&
3225 cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && 3230 cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD &&
3226 new_cfqq->service_tree->count == 2 && 3231 new_cfqq->service_tree->count == 2 &&
3227 RB_EMPTY_ROOT(&cfqq->sort_list)) 3232 RB_EMPTY_ROOT(&cfqq->sort_list))
3228 return true; 3233 return true;
3229 3234
3230 /* 3235 /*
3231 * So both queues are sync. Let the new request get disk time if 3236 * So both queues are sync. Let the new request get disk time if
3232 * it's a metadata request and the current queue is doing regular IO. 3237 * it's a metadata request and the current queue is doing regular IO.
3233 */ 3238 */
3234 if ((rq->cmd_flags & REQ_META) && !cfqq->meta_pending) 3239 if ((rq->cmd_flags & REQ_META) && !cfqq->meta_pending)
3235 return true; 3240 return true;
3236 3241
3237 /* 3242 /*
3238 * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. 3243 * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice.
3239 */ 3244 */
3240 if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) 3245 if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq))
3241 return true; 3246 return true;
3242 3247
3243 if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) 3248 if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq))
3244 return false; 3249 return false;
3245 3250
3246 /* 3251 /*
3247 * if this request is as-good as one we would expect from the 3252 * if this request is as-good as one we would expect from the
3248 * current cfqq, let it preempt 3253 * current cfqq, let it preempt
3249 */ 3254 */
3250 if (cfq_rq_close(cfqd, cfqq, rq)) 3255 if (cfq_rq_close(cfqd, cfqq, rq))
3251 return true; 3256 return true;
3252 3257
3253 return false; 3258 return false;
3254 } 3259 }
3255 3260
3256 /* 3261 /*
3257 * cfqq preempts the active queue. if we allowed preempt with no slice left, 3262 * cfqq preempts the active queue. if we allowed preempt with no slice left,
3258 * let it have half of its nominal slice. 3263 * let it have half of its nominal slice.
3259 */ 3264 */
3260 static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) 3265 static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
3261 { 3266 {
3262 cfq_log_cfqq(cfqd, cfqq, "preempt"); 3267 cfq_log_cfqq(cfqd, cfqq, "preempt");
3263 cfq_slice_expired(cfqd, 1); 3268 cfq_slice_expired(cfqd, 1);
3264 3269
3265 /* 3270 /*
3266 * Put the new queue at the front of the of the current list, 3271 * Put the new queue at the front of the of the current list,
3267 * so we know that it will be selected next. 3272 * so we know that it will be selected next.
3268 */ 3273 */
3269 BUG_ON(!cfq_cfqq_on_rr(cfqq)); 3274 BUG_ON(!cfq_cfqq_on_rr(cfqq));
3270 3275
3271 cfq_service_tree_add(cfqd, cfqq, 1); 3276 cfq_service_tree_add(cfqd, cfqq, 1);
3272 3277
3273 cfqq->slice_end = 0; 3278 cfqq->slice_end = 0;
3274 cfq_mark_cfqq_slice_new(cfqq); 3279 cfq_mark_cfqq_slice_new(cfqq);
3275 } 3280 }
3276 3281
3277 /* 3282 /*
3278 * Called when a new fs request (rq) is added (to cfqq). Check if there's 3283 * Called when a new fs request (rq) is added (to cfqq). Check if there's
3279 * something we should do about it 3284 * something we should do about it
3280 */ 3285 */
3281 static void 3286 static void
3282 cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, 3287 cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
3283 struct request *rq) 3288 struct request *rq)
3284 { 3289 {
3285 struct cfq_io_context *cic = RQ_CIC(rq); 3290 struct cfq_io_context *cic = RQ_CIC(rq);
3286 3291
3287 cfqd->rq_queued++; 3292 cfqd->rq_queued++;
3288 if (rq->cmd_flags & REQ_META) 3293 if (rq->cmd_flags & REQ_META)
3289 cfqq->meta_pending++; 3294 cfqq->meta_pending++;
3290 3295
3291 cfq_update_io_thinktime(cfqd, cic); 3296 cfq_update_io_thinktime(cfqd, cic);
3292 cfq_update_io_seektime(cfqd, cfqq, rq); 3297 cfq_update_io_seektime(cfqd, cfqq, rq);
3293 cfq_update_idle_window(cfqd, cfqq, cic); 3298 cfq_update_idle_window(cfqd, cfqq, cic);
3294 3299
3295 cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); 3300 cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq);
3296 3301
3297 if (cfqq == cfqd->active_queue) { 3302 if (cfqq == cfqd->active_queue) {
3298 /* 3303 /*
3299 * Remember that we saw a request from this process, but 3304 * Remember that we saw a request from this process, but
3300 * don't start queuing just yet. Otherwise we risk seeing lots 3305 * don't start queuing just yet. Otherwise we risk seeing lots
3301 * of tiny requests, because we disrupt the normal plugging 3306 * of tiny requests, because we disrupt the normal plugging
3302 * and merging. If the request is already larger than a single 3307 * and merging. If the request is already larger than a single
3303 * page, let it rip immediately. For that case we assume that 3308 * page, let it rip immediately. For that case we assume that
3304 * merging is already done. Ditto for a busy system that 3309 * merging is already done. Ditto for a busy system that
3305 * has other work pending, don't risk delaying until the 3310 * has other work pending, don't risk delaying until the
3306 * idle timer unplug to continue working. 3311 * idle timer unplug to continue working.
3307 */ 3312 */
3308 if (cfq_cfqq_wait_request(cfqq)) { 3313 if (cfq_cfqq_wait_request(cfqq)) {
3309 if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || 3314 if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE ||
3310 cfqd->busy_queues > 1) { 3315 cfqd->busy_queues > 1) {
3311 cfq_del_timer(cfqd, cfqq); 3316 cfq_del_timer(cfqd, cfqq);
3312 cfq_clear_cfqq_wait_request(cfqq); 3317 cfq_clear_cfqq_wait_request(cfqq);
3313 __blk_run_queue(cfqd->queue); 3318 __blk_run_queue(cfqd->queue);
3314 } else { 3319 } else {
3315 cfq_blkiocg_update_idle_time_stats( 3320 cfq_blkiocg_update_idle_time_stats(
3316 &cfqq->cfqg->blkg); 3321 &cfqq->cfqg->blkg);
3317 cfq_mark_cfqq_must_dispatch(cfqq); 3322 cfq_mark_cfqq_must_dispatch(cfqq);
3318 } 3323 }
3319 } 3324 }
3320 } else if (cfq_should_preempt(cfqd, cfqq, rq)) { 3325 } else if (cfq_should_preempt(cfqd, cfqq, rq)) {
3321 /* 3326 /*
3322 * not the active queue - expire current slice if it is 3327 * not the active queue - expire current slice if it is
3323 * idle and has expired it's mean thinktime or this new queue 3328 * idle and has expired it's mean thinktime or this new queue
3324 * has some old slice time left and is of higher priority or 3329 * has some old slice time left and is of higher priority or
3325 * this new queue is RT and the current one is BE 3330 * this new queue is RT and the current one is BE
3326 */ 3331 */
3327 cfq_preempt_queue(cfqd, cfqq); 3332 cfq_preempt_queue(cfqd, cfqq);
3328 __blk_run_queue(cfqd->queue); 3333 __blk_run_queue(cfqd->queue);
3329 } 3334 }
3330 } 3335 }
3331 3336
3332 static void cfq_insert_request(struct request_queue *q, struct request *rq) 3337 static void cfq_insert_request(struct request_queue *q, struct request *rq)
3333 { 3338 {
3334 struct cfq_data *cfqd = q->elevator->elevator_data; 3339 struct cfq_data *cfqd = q->elevator->elevator_data;
3335 struct cfq_queue *cfqq = RQ_CFQQ(rq); 3340 struct cfq_queue *cfqq = RQ_CFQQ(rq);
3336 3341
3337 cfq_log_cfqq(cfqd, cfqq, "insert_request"); 3342 cfq_log_cfqq(cfqd, cfqq, "insert_request");
3338 cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc); 3343 cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc);
3339 3344
3340 rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]); 3345 rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]);
3341 list_add_tail(&rq->queuelist, &cfqq->fifo); 3346 list_add_tail(&rq->queuelist, &cfqq->fifo);
3342 cfq_add_rq_rb(rq); 3347 cfq_add_rq_rb(rq);
3343 cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg, 3348 cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
3344 &cfqd->serving_group->blkg, rq_data_dir(rq), 3349 &cfqd->serving_group->blkg, rq_data_dir(rq),
3345 rq_is_sync(rq)); 3350 rq_is_sync(rq));
3346 cfq_rq_enqueued(cfqd, cfqq, rq); 3351 cfq_rq_enqueued(cfqd, cfqq, rq);
3347 } 3352 }
3348 3353
3349 /* 3354 /*
3350 * Update hw_tag based on peak queue depth over 50 samples under 3355 * Update hw_tag based on peak queue depth over 50 samples under
3351 * sufficient load. 3356 * sufficient load.
3352 */ 3357 */
3353 static void cfq_update_hw_tag(struct cfq_data *cfqd) 3358 static void cfq_update_hw_tag(struct cfq_data *cfqd)
3354 { 3359 {
3355 struct cfq_queue *cfqq = cfqd->active_queue; 3360 struct cfq_queue *cfqq = cfqd->active_queue;
3356 3361
3357 if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth) 3362 if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth)
3358 cfqd->hw_tag_est_depth = cfqd->rq_in_driver; 3363 cfqd->hw_tag_est_depth = cfqd->rq_in_driver;
3359 3364
3360 if (cfqd->hw_tag == 1) 3365 if (cfqd->hw_tag == 1)
3361 return; 3366 return;
3362 3367
3363 if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && 3368 if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN &&
3364 cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) 3369 cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN)
3365 return; 3370 return;
3366 3371
3367 /* 3372 /*
3368 * If active queue hasn't enough requests and can idle, cfq might not 3373 * If active queue hasn't enough requests and can idle, cfq might not
3369 * dispatch sufficient requests to hardware. Don't zero hw_tag in this 3374 * dispatch sufficient requests to hardware. Don't zero hw_tag in this
3370 * case 3375 * case
3371 */ 3376 */
3372 if (cfqq && cfq_cfqq_idle_window(cfqq) && 3377 if (cfqq && cfq_cfqq_idle_window(cfqq) &&
3373 cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < 3378 cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] <
3374 CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN) 3379 CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN)
3375 return; 3380 return;
3376 3381
3377 if (cfqd->hw_tag_samples++ < 50) 3382 if (cfqd->hw_tag_samples++ < 50)
3378 return; 3383 return;
3379 3384
3380 if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN) 3385 if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN)
3381 cfqd->hw_tag = 1; 3386 cfqd->hw_tag = 1;
3382 else 3387 else
3383 cfqd->hw_tag = 0; 3388 cfqd->hw_tag = 0;
3384 } 3389 }
3385 3390
3386 static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) 3391 static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq)
3387 { 3392 {
3388 struct cfq_io_context *cic = cfqd->active_cic; 3393 struct cfq_io_context *cic = cfqd->active_cic;
3389 3394
3390 /* If there are other queues in the group, don't wait */ 3395 /* If there are other queues in the group, don't wait */
3391 if (cfqq->cfqg->nr_cfqq > 1) 3396 if (cfqq->cfqg->nr_cfqq > 1)
3392 return false; 3397 return false;
3393 3398
3394 if (cfq_slice_used(cfqq)) 3399 if (cfq_slice_used(cfqq))
3395 return true; 3400 return true;
3396 3401
3397 /* if slice left is less than think time, wait busy */ 3402 /* if slice left is less than think time, wait busy */
3398 if (cic && sample_valid(cic->ttime_samples) 3403 if (cic && sample_valid(cic->ttime_samples)
3399 && (cfqq->slice_end - jiffies < cic->ttime_mean)) 3404 && (cfqq->slice_end - jiffies < cic->ttime_mean))
3400 return true; 3405 return true;
3401 3406
3402 /* 3407 /*
3403 * If think times is less than a jiffy than ttime_mean=0 and above 3408 * If think times is less than a jiffy than ttime_mean=0 and above
3404 * will not be true. It might happen that slice has not expired yet 3409 * will not be true. It might happen that slice has not expired yet
3405 * but will expire soon (4-5 ns) during select_queue(). To cover the 3410 * but will expire soon (4-5 ns) during select_queue(). To cover the
3406 * case where think time is less than a jiffy, mark the queue wait 3411 * case where think time is less than a jiffy, mark the queue wait
3407 * busy if only 1 jiffy is left in the slice. 3412 * busy if only 1 jiffy is left in the slice.
3408 */ 3413 */
3409 if (cfqq->slice_end - jiffies == 1) 3414 if (cfqq->slice_end - jiffies == 1)
3410 return true; 3415 return true;
3411 3416
3412 return false; 3417 return false;
3413 } 3418 }
3414 3419
3415 static void cfq_completed_request(struct request_queue *q, struct request *rq) 3420 static void cfq_completed_request(struct request_queue *q, struct request *rq)
3416 { 3421 {
3417 struct cfq_queue *cfqq = RQ_CFQQ(rq); 3422 struct cfq_queue *cfqq = RQ_CFQQ(rq);
3418 struct cfq_data *cfqd = cfqq->cfqd; 3423 struct cfq_data *cfqd = cfqq->cfqd;
3419 const int sync = rq_is_sync(rq); 3424 const int sync = rq_is_sync(rq);
3420 unsigned long now; 3425 unsigned long now;
3421 3426
3422 now = jiffies; 3427 now = jiffies;
3423 cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", 3428 cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d",
3424 !!(rq->cmd_flags & REQ_NOIDLE)); 3429 !!(rq->cmd_flags & REQ_NOIDLE));
3425 3430
3426 cfq_update_hw_tag(cfqd); 3431 cfq_update_hw_tag(cfqd);
3427 3432
3428 WARN_ON(!cfqd->rq_in_driver); 3433 WARN_ON(!cfqd->rq_in_driver);
3429 WARN_ON(!cfqq->dispatched); 3434 WARN_ON(!cfqq->dispatched);
3430 cfqd->rq_in_driver--; 3435 cfqd->rq_in_driver--;
3431 cfqq->dispatched--; 3436 cfqq->dispatched--;
3432 (RQ_CFQG(rq))->dispatched--; 3437 (RQ_CFQG(rq))->dispatched--;
3433 cfq_blkiocg_update_completion_stats(&cfqq->cfqg->blkg, 3438 cfq_blkiocg_update_completion_stats(&cfqq->cfqg->blkg,
3434 rq_start_time_ns(rq), rq_io_start_time_ns(rq), 3439 rq_start_time_ns(rq), rq_io_start_time_ns(rq),
3435 rq_data_dir(rq), rq_is_sync(rq)); 3440 rq_data_dir(rq), rq_is_sync(rq));
3436 3441
3437 cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--; 3442 cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
3438 3443
3439 if (sync) { 3444 if (sync) {
3440 RQ_CIC(rq)->last_end_request = now; 3445 RQ_CIC(rq)->last_end_request = now;
3441 if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) 3446 if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now))
3442 cfqd->last_delayed_sync = now; 3447 cfqd->last_delayed_sync = now;
3443 } 3448 }
3444 3449
3445 /* 3450 /*
3446 * If this is the active queue, check if it needs to be expired, 3451 * If this is the active queue, check if it needs to be expired,
3447 * or if we want to idle in case it has no pending requests. 3452 * or if we want to idle in case it has no pending requests.
3448 */ 3453 */
3449 if (cfqd->active_queue == cfqq) { 3454 if (cfqd->active_queue == cfqq) {
3450 const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); 3455 const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list);
3451 3456
3452 if (cfq_cfqq_slice_new(cfqq)) { 3457 if (cfq_cfqq_slice_new(cfqq)) {
3453 cfq_set_prio_slice(cfqd, cfqq); 3458 cfq_set_prio_slice(cfqd, cfqq);
3454 cfq_clear_cfqq_slice_new(cfqq); 3459 cfq_clear_cfqq_slice_new(cfqq);
3455 } 3460 }
3456 3461
3457 /* 3462 /*
3458 * Should we wait for next request to come in before we expire 3463 * Should we wait for next request to come in before we expire
3459 * the queue. 3464 * the queue.
3460 */ 3465 */
3461 if (cfq_should_wait_busy(cfqd, cfqq)) { 3466 if (cfq_should_wait_busy(cfqd, cfqq)) {
3462 unsigned long extend_sl = cfqd->cfq_slice_idle; 3467 unsigned long extend_sl = cfqd->cfq_slice_idle;
3463 if (!cfqd->cfq_slice_idle) 3468 if (!cfqd->cfq_slice_idle)
3464 extend_sl = cfqd->cfq_group_idle; 3469 extend_sl = cfqd->cfq_group_idle;
3465 cfqq->slice_end = jiffies + extend_sl; 3470 cfqq->slice_end = jiffies + extend_sl;
3466 cfq_mark_cfqq_wait_busy(cfqq); 3471 cfq_mark_cfqq_wait_busy(cfqq);
3467 cfq_log_cfqq(cfqd, cfqq, "will busy wait"); 3472 cfq_log_cfqq(cfqd, cfqq, "will busy wait");
3468 } 3473 }
3469 3474
3470 /* 3475 /*
3471 * Idling is not enabled on: 3476 * Idling is not enabled on:
3472 * - expired queues 3477 * - expired queues
3473 * - idle-priority queues 3478 * - idle-priority queues
3474 * - async queues 3479 * - async queues
3475 * - queues with still some requests queued 3480 * - queues with still some requests queued
3476 * - when there is a close cooperator 3481 * - when there is a close cooperator
3477 */ 3482 */
3478 if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) 3483 if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq))
3479 cfq_slice_expired(cfqd, 1); 3484 cfq_slice_expired(cfqd, 1);
3480 else if (sync && cfqq_empty && 3485 else if (sync && cfqq_empty &&
3481 !cfq_close_cooperator(cfqd, cfqq)) { 3486 !cfq_close_cooperator(cfqd, cfqq)) {
3482 cfqd->noidle_tree_requires_idle |= 3487 cfqd->noidle_tree_requires_idle |=
3483 !(rq->cmd_flags & REQ_NOIDLE); 3488 !(rq->cmd_flags & REQ_NOIDLE);
3484 /* 3489 /*
3485 * Idling is enabled for SYNC_WORKLOAD. 3490 * Idling is enabled for SYNC_WORKLOAD.
3486 * SYNC_NOIDLE_WORKLOAD idles at the end of the tree 3491 * SYNC_NOIDLE_WORKLOAD idles at the end of the tree
3487 * only if we processed at least one !REQ_NOIDLE request 3492 * only if we processed at least one !REQ_NOIDLE request
3488 */ 3493 */
3489 if (cfqd->serving_type == SYNC_WORKLOAD 3494 if (cfqd->serving_type == SYNC_WORKLOAD
3490 || cfqd->noidle_tree_requires_idle 3495 || cfqd->noidle_tree_requires_idle
3491 || cfqq->cfqg->nr_cfqq == 1) 3496 || cfqq->cfqg->nr_cfqq == 1)
3492 cfq_arm_slice_timer(cfqd); 3497 cfq_arm_slice_timer(cfqd);
3493 } 3498 }
3494 } 3499 }
3495 3500
3496 if (!cfqd->rq_in_driver) 3501 if (!cfqd->rq_in_driver)
3497 cfq_schedule_dispatch(cfqd); 3502 cfq_schedule_dispatch(cfqd);
3498 } 3503 }
3499 3504
3500 /* 3505 /*
3501 * we temporarily boost lower priority queues if they are holding fs exclusive 3506 * we temporarily boost lower priority queues if they are holding fs exclusive
3502 * resources. they are boosted to normal prio (CLASS_BE/4) 3507 * resources. they are boosted to normal prio (CLASS_BE/4)
3503 */ 3508 */
3504 static void cfq_prio_boost(struct cfq_queue *cfqq) 3509 static void cfq_prio_boost(struct cfq_queue *cfqq)
3505 { 3510 {
3506 if (has_fs_excl()) { 3511 if (has_fs_excl()) {
3507 /* 3512 /*
3508 * boost idle prio on transactions that would lock out other 3513 * boost idle prio on transactions that would lock out other
3509 * users of the filesystem 3514 * users of the filesystem
3510 */ 3515 */
3511 if (cfq_class_idle(cfqq)) 3516 if (cfq_class_idle(cfqq))
3512 cfqq->ioprio_class = IOPRIO_CLASS_BE; 3517 cfqq->ioprio_class = IOPRIO_CLASS_BE;
3513 if (cfqq->ioprio > IOPRIO_NORM) 3518 if (cfqq->ioprio > IOPRIO_NORM)
3514 cfqq->ioprio = IOPRIO_NORM; 3519 cfqq->ioprio = IOPRIO_NORM;
3515 } else { 3520 } else {
3516 /* 3521 /*
3517 * unboost the queue (if needed) 3522 * unboost the queue (if needed)
3518 */ 3523 */
3519 cfqq->ioprio_class = cfqq->org_ioprio_class; 3524 cfqq->ioprio_class = cfqq->org_ioprio_class;
3520 cfqq->ioprio = cfqq->org_ioprio; 3525 cfqq->ioprio = cfqq->org_ioprio;
3521 } 3526 }
3522 } 3527 }
3523 3528
3524 static inline int __cfq_may_queue(struct cfq_queue *cfqq) 3529 static inline int __cfq_may_queue(struct cfq_queue *cfqq)
3525 { 3530 {
3526 if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { 3531 if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) {
3527 cfq_mark_cfqq_must_alloc_slice(cfqq); 3532 cfq_mark_cfqq_must_alloc_slice(cfqq);
3528 return ELV_MQUEUE_MUST; 3533 return ELV_MQUEUE_MUST;
3529 } 3534 }
3530 3535
3531 return ELV_MQUEUE_MAY; 3536 return ELV_MQUEUE_MAY;
3532 } 3537 }
3533 3538
3534 static int cfq_may_queue(struct request_queue *q, int rw) 3539 static int cfq_may_queue(struct request_queue *q, int rw)
3535 { 3540 {
3536 struct cfq_data *cfqd = q->elevator->elevator_data; 3541 struct cfq_data *cfqd = q->elevator->elevator_data;
3537 struct task_struct *tsk = current; 3542 struct task_struct *tsk = current;
3538 struct cfq_io_context *cic; 3543 struct cfq_io_context *cic;
3539 struct cfq_queue *cfqq; 3544 struct cfq_queue *cfqq;
3540 3545
3541 /* 3546 /*
3542 * don't force setup of a queue from here, as a call to may_queue 3547 * don't force setup of a queue from here, as a call to may_queue
3543 * does not necessarily imply that a request actually will be queued. 3548 * does not necessarily imply that a request actually will be queued.
3544 * so just lookup a possibly existing queue, or return 'may queue' 3549 * so just lookup a possibly existing queue, or return 'may queue'
3545 * if that fails 3550 * if that fails
3546 */ 3551 */
3547 cic = cfq_cic_lookup(cfqd, tsk->io_context); 3552 cic = cfq_cic_lookup(cfqd, tsk->io_context);
3548 if (!cic) 3553 if (!cic)
3549 return ELV_MQUEUE_MAY; 3554 return ELV_MQUEUE_MAY;
3550 3555
3551 cfqq = cic_to_cfqq(cic, rw_is_sync(rw)); 3556 cfqq = cic_to_cfqq(cic, rw_is_sync(rw));
3552 if (cfqq) { 3557 if (cfqq) {
3553 cfq_init_prio_data(cfqq, cic->ioc); 3558 cfq_init_prio_data(cfqq, cic->ioc);
3554 cfq_prio_boost(cfqq); 3559 cfq_prio_boost(cfqq);
3555 3560
3556 return __cfq_may_queue(cfqq); 3561 return __cfq_may_queue(cfqq);
3557 } 3562 }
3558 3563
3559 return ELV_MQUEUE_MAY; 3564 return ELV_MQUEUE_MAY;
3560 } 3565 }
3561 3566
3562 /* 3567 /*
3563 * queue lock held here 3568 * queue lock held here
3564 */ 3569 */
3565 static void cfq_put_request(struct request *rq) 3570 static void cfq_put_request(struct request *rq)
3566 { 3571 {
3567 struct cfq_queue *cfqq = RQ_CFQQ(rq); 3572 struct cfq_queue *cfqq = RQ_CFQQ(rq);
3568 3573
3569 if (cfqq) { 3574 if (cfqq) {
3570 const int rw = rq_data_dir(rq); 3575 const int rw = rq_data_dir(rq);
3571 3576
3572 BUG_ON(!cfqq->allocated[rw]); 3577 BUG_ON(!cfqq->allocated[rw]);
3573 cfqq->allocated[rw]--; 3578 cfqq->allocated[rw]--;
3574 3579
3575 put_io_context(RQ_CIC(rq)->ioc); 3580 put_io_context(RQ_CIC(rq)->ioc);
3576 3581
3577 rq->elevator_private = NULL; 3582 rq->elevator_private = NULL;
3578 rq->elevator_private2 = NULL; 3583 rq->elevator_private2 = NULL;
3579 3584
3580 /* Put down rq reference on cfqg */ 3585 /* Put down rq reference on cfqg */
3581 cfq_put_cfqg(RQ_CFQG(rq)); 3586 cfq_put_cfqg(RQ_CFQG(rq));
3582 rq->elevator_private3 = NULL; 3587 rq->elevator_private3 = NULL;
3583 3588
3584 cfq_put_queue(cfqq); 3589 cfq_put_queue(cfqq);
3585 } 3590 }
3586 } 3591 }
3587 3592
3588 static struct cfq_queue * 3593 static struct cfq_queue *
3589 cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_context *cic, 3594 cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_context *cic,
3590 struct cfq_queue *cfqq) 3595 struct cfq_queue *cfqq)
3591 { 3596 {
3592 cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq); 3597 cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq);
3593 cic_set_cfqq(cic, cfqq->new_cfqq, 1); 3598 cic_set_cfqq(cic, cfqq->new_cfqq, 1);
3594 cfq_mark_cfqq_coop(cfqq->new_cfqq); 3599 cfq_mark_cfqq_coop(cfqq->new_cfqq);
3595 cfq_put_queue(cfqq); 3600 cfq_put_queue(cfqq);
3596 return cic_to_cfqq(cic, 1); 3601 return cic_to_cfqq(cic, 1);
3597 } 3602 }
3598 3603
3599 /* 3604 /*
3600 * Returns NULL if a new cfqq should be allocated, or the old cfqq if this 3605 * Returns NULL if a new cfqq should be allocated, or the old cfqq if this
3601 * was the last process referring to said cfqq. 3606 * was the last process referring to said cfqq.
3602 */ 3607 */
3603 static struct cfq_queue * 3608 static struct cfq_queue *
3604 split_cfqq(struct cfq_io_context *cic, struct cfq_queue *cfqq) 3609 split_cfqq(struct cfq_io_context *cic, struct cfq_queue *cfqq)
3605 { 3610 {
3606 if (cfqq_process_refs(cfqq) == 1) { 3611 if (cfqq_process_refs(cfqq) == 1) {
3607 cfqq->pid = current->pid; 3612 cfqq->pid = current->pid;
3608 cfq_clear_cfqq_coop(cfqq); 3613 cfq_clear_cfqq_coop(cfqq);
3609 cfq_clear_cfqq_split_coop(cfqq); 3614 cfq_clear_cfqq_split_coop(cfqq);
3610 return cfqq; 3615 return cfqq;
3611 } 3616 }
3612 3617
3613 cic_set_cfqq(cic, NULL, 1); 3618 cic_set_cfqq(cic, NULL, 1);
3614 3619
3615 cfq_put_cooperator(cfqq); 3620 cfq_put_cooperator(cfqq);
3616 3621
3617 cfq_put_queue(cfqq); 3622 cfq_put_queue(cfqq);
3618 return NULL; 3623 return NULL;
3619 } 3624 }
3620 /* 3625 /*
3621 * Allocate cfq data structures associated with this request. 3626 * Allocate cfq data structures associated with this request.
3622 */ 3627 */
3623 static int 3628 static int
3624 cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) 3629 cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
3625 { 3630 {
3626 struct cfq_data *cfqd = q->elevator->elevator_data; 3631 struct cfq_data *cfqd = q->elevator->elevator_data;
3627 struct cfq_io_context *cic; 3632 struct cfq_io_context *cic;
3628 const int rw = rq_data_dir(rq); 3633 const int rw = rq_data_dir(rq);
3629 const bool is_sync = rq_is_sync(rq); 3634 const bool is_sync = rq_is_sync(rq);
3630 struct cfq_queue *cfqq; 3635 struct cfq_queue *cfqq;
3631 unsigned long flags; 3636 unsigned long flags;
3632 3637
3633 might_sleep_if(gfp_mask & __GFP_WAIT); 3638 might_sleep_if(gfp_mask & __GFP_WAIT);
3634 3639
3635 cic = cfq_get_io_context(cfqd, gfp_mask); 3640 cic = cfq_get_io_context(cfqd, gfp_mask);
3636 3641
3637 spin_lock_irqsave(q->queue_lock, flags); 3642 spin_lock_irqsave(q->queue_lock, flags);
3638 3643
3639 if (!cic) 3644 if (!cic)
3640 goto queue_fail; 3645 goto queue_fail;
3641 3646
3642 new_queue: 3647 new_queue:
3643 cfqq = cic_to_cfqq(cic, is_sync); 3648 cfqq = cic_to_cfqq(cic, is_sync);
3644 if (!cfqq || cfqq == &cfqd->oom_cfqq) { 3649 if (!cfqq || cfqq == &cfqd->oom_cfqq) {
3645 cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask); 3650 cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask);
3646 cic_set_cfqq(cic, cfqq, is_sync); 3651 cic_set_cfqq(cic, cfqq, is_sync);
3647 } else { 3652 } else {
3648 /* 3653 /*
3649 * If the queue was seeky for too long, break it apart. 3654 * If the queue was seeky for too long, break it apart.
3650 */ 3655 */
3651 if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) { 3656 if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) {
3652 cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); 3657 cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq");
3653 cfqq = split_cfqq(cic, cfqq); 3658 cfqq = split_cfqq(cic, cfqq);
3654 if (!cfqq) 3659 if (!cfqq)
3655 goto new_queue; 3660 goto new_queue;
3656 } 3661 }
3657 3662
3658 /* 3663 /*
3659 * Check to see if this queue is scheduled to merge with 3664 * Check to see if this queue is scheduled to merge with
3660 * another, closely cooperating queue. The merging of 3665 * another, closely cooperating queue. The merging of
3661 * queues happens here as it must be done in process context. 3666 * queues happens here as it must be done in process context.
3662 * The reference on new_cfqq was taken in merge_cfqqs. 3667 * The reference on new_cfqq was taken in merge_cfqqs.
3663 */ 3668 */
3664 if (cfqq->new_cfqq) 3669 if (cfqq->new_cfqq)
3665 cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq); 3670 cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq);
3666 } 3671 }
3667 3672
3668 cfqq->allocated[rw]++; 3673 cfqq->allocated[rw]++;
3669 atomic_inc(&cfqq->ref); 3674 atomic_inc(&cfqq->ref);
3670 3675
3671 spin_unlock_irqrestore(q->queue_lock, flags); 3676 spin_unlock_irqrestore(q->queue_lock, flags);
3672 3677
3673 rq->elevator_private = cic; 3678 rq->elevator_private = cic;
3674 rq->elevator_private2 = cfqq; 3679 rq->elevator_private2 = cfqq;
3675 rq->elevator_private3 = cfq_ref_get_cfqg(cfqq->cfqg); 3680 rq->elevator_private3 = cfq_ref_get_cfqg(cfqq->cfqg);
3676 return 0; 3681 return 0;
3677 3682
3678 queue_fail: 3683 queue_fail:
3679 if (cic) 3684 if (cic)
3680 put_io_context(cic->ioc); 3685 put_io_context(cic->ioc);
3681 3686
3682 cfq_schedule_dispatch(cfqd); 3687 cfq_schedule_dispatch(cfqd);
3683 spin_unlock_irqrestore(q->queue_lock, flags); 3688 spin_unlock_irqrestore(q->queue_lock, flags);
3684 cfq_log(cfqd, "set_request fail"); 3689 cfq_log(cfqd, "set_request fail");
3685 return 1; 3690 return 1;
3686 } 3691 }
3687 3692
3688 static void cfq_kick_queue(struct work_struct *work) 3693 static void cfq_kick_queue(struct work_struct *work)
3689 { 3694 {
3690 struct cfq_data *cfqd = 3695 struct cfq_data *cfqd =
3691 container_of(work, struct cfq_data, unplug_work); 3696 container_of(work, struct cfq_data, unplug_work);
3692 struct request_queue *q = cfqd->queue; 3697 struct request_queue *q = cfqd->queue;
3693 3698
3694 spin_lock_irq(q->queue_lock); 3699 spin_lock_irq(q->queue_lock);
3695 __blk_run_queue(cfqd->queue); 3700 __blk_run_queue(cfqd->queue);
3696 spin_unlock_irq(q->queue_lock); 3701 spin_unlock_irq(q->queue_lock);
3697 } 3702 }
3698 3703
3699 /* 3704 /*
3700 * Timer running if the active_queue is currently idling inside its time slice 3705 * Timer running if the active_queue is currently idling inside its time slice
3701 */ 3706 */
3702 static void cfq_idle_slice_timer(unsigned long data) 3707 static void cfq_idle_slice_timer(unsigned long data)
3703 { 3708 {
3704 struct cfq_data *cfqd = (struct cfq_data *) data; 3709 struct cfq_data *cfqd = (struct cfq_data *) data;
3705 struct cfq_queue *cfqq; 3710 struct cfq_queue *cfqq;
3706 unsigned long flags; 3711 unsigned long flags;
3707 int timed_out = 1; 3712 int timed_out = 1;
3708 3713
3709 cfq_log(cfqd, "idle timer fired"); 3714 cfq_log(cfqd, "idle timer fired");
3710 3715
3711 spin_lock_irqsave(cfqd->queue->queue_lock, flags); 3716 spin_lock_irqsave(cfqd->queue->queue_lock, flags);
3712 3717
3713 cfqq = cfqd->active_queue; 3718 cfqq = cfqd->active_queue;
3714 if (cfqq) { 3719 if (cfqq) {
3715 timed_out = 0; 3720 timed_out = 0;
3716 3721
3717 /* 3722 /*
3718 * We saw a request before the queue expired, let it through 3723 * We saw a request before the queue expired, let it through
3719 */ 3724 */
3720 if (cfq_cfqq_must_dispatch(cfqq)) 3725 if (cfq_cfqq_must_dispatch(cfqq))
3721 goto out_kick; 3726 goto out_kick;
3722 3727
3723 /* 3728 /*
3724 * expired 3729 * expired
3725 */ 3730 */
3726 if (cfq_slice_used(cfqq)) 3731 if (cfq_slice_used(cfqq))
3727 goto expire; 3732 goto expire;
3728 3733
3729 /* 3734 /*
3730 * only expire and reinvoke request handler, if there are 3735 * only expire and reinvoke request handler, if there are
3731 * other queues with pending requests 3736 * other queues with pending requests
3732 */ 3737 */
3733 if (!cfqd->busy_queues) 3738 if (!cfqd->busy_queues)
3734 goto out_cont; 3739 goto out_cont;
3735 3740
3736 /* 3741 /*
3737 * not expired and it has a request pending, let it dispatch 3742 * not expired and it has a request pending, let it dispatch
3738 */ 3743 */
3739 if (!RB_EMPTY_ROOT(&cfqq->sort_list)) 3744 if (!RB_EMPTY_ROOT(&cfqq->sort_list))
3740 goto out_kick; 3745 goto out_kick;
3741 3746
3742 /* 3747 /*
3743 * Queue depth flag is reset only when the idle didn't succeed 3748 * Queue depth flag is reset only when the idle didn't succeed
3744 */ 3749 */
3745 cfq_clear_cfqq_deep(cfqq); 3750 cfq_clear_cfqq_deep(cfqq);
3746 } 3751 }
3747 expire: 3752 expire:
3748 cfq_slice_expired(cfqd, timed_out); 3753 cfq_slice_expired(cfqd, timed_out);
3749 out_kick: 3754 out_kick:
3750 cfq_schedule_dispatch(cfqd); 3755 cfq_schedule_dispatch(cfqd);
3751 out_cont: 3756 out_cont:
3752 spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); 3757 spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
3753 } 3758 }
3754 3759
3755 static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) 3760 static void cfq_shutdown_timer_wq(struct cfq_data *cfqd)
3756 { 3761 {
3757 del_timer_sync(&cfqd->idle_slice_timer); 3762 del_timer_sync(&cfqd->idle_slice_timer);
3758 cancel_work_sync(&cfqd->unplug_work); 3763 cancel_work_sync(&cfqd->unplug_work);
3759 } 3764 }
3760 3765
3761 static void cfq_put_async_queues(struct cfq_data *cfqd) 3766 static void cfq_put_async_queues(struct cfq_data *cfqd)
3762 { 3767 {
3763 int i; 3768 int i;
3764 3769
3765 for (i = 0; i < IOPRIO_BE_NR; i++) { 3770 for (i = 0; i < IOPRIO_BE_NR; i++) {
3766 if (cfqd->async_cfqq[0][i]) 3771 if (cfqd->async_cfqq[0][i])
3767 cfq_put_queue(cfqd->async_cfqq[0][i]); 3772 cfq_put_queue(cfqd->async_cfqq[0][i]);
3768 if (cfqd->async_cfqq[1][i]) 3773 if (cfqd->async_cfqq[1][i])
3769 cfq_put_queue(cfqd->async_cfqq[1][i]); 3774 cfq_put_queue(cfqd->async_cfqq[1][i]);
3770 } 3775 }
3771 3776
3772 if (cfqd->async_idle_cfqq) 3777 if (cfqd->async_idle_cfqq)
3773 cfq_put_queue(cfqd->async_idle_cfqq); 3778 cfq_put_queue(cfqd->async_idle_cfqq);
3774 } 3779 }
3775 3780
3776 static void cfq_cfqd_free(struct rcu_head *head) 3781 static void cfq_cfqd_free(struct rcu_head *head)
3777 { 3782 {
3778 kfree(container_of(head, struct cfq_data, rcu)); 3783 kfree(container_of(head, struct cfq_data, rcu));
3779 } 3784 }
3780 3785
3781 static void cfq_exit_queue(struct elevator_queue *e) 3786 static void cfq_exit_queue(struct elevator_queue *e)
3782 { 3787 {
3783 struct cfq_data *cfqd = e->elevator_data; 3788 struct cfq_data *cfqd = e->elevator_data;
3784 struct request_queue *q = cfqd->queue; 3789 struct request_queue *q = cfqd->queue;
3785 3790
3786 cfq_shutdown_timer_wq(cfqd); 3791 cfq_shutdown_timer_wq(cfqd);
3787 3792
3788 spin_lock_irq(q->queue_lock); 3793 spin_lock_irq(q->queue_lock);
3789 3794
3790 if (cfqd->active_queue) 3795 if (cfqd->active_queue)
3791 __cfq_slice_expired(cfqd, cfqd->active_queue, 0); 3796 __cfq_slice_expired(cfqd, cfqd->active_queue, 0);
3792 3797
3793 while (!list_empty(&cfqd->cic_list)) { 3798 while (!list_empty(&cfqd->cic_list)) {
3794 struct cfq_io_context *cic = list_entry(cfqd->cic_list.next, 3799 struct cfq_io_context *cic = list_entry(cfqd->cic_list.next,
3795 struct cfq_io_context, 3800 struct cfq_io_context,
3796 queue_list); 3801 queue_list);
3797 3802
3798 __cfq_exit_single_io_context(cfqd, cic); 3803 __cfq_exit_single_io_context(cfqd, cic);
3799 } 3804 }
3800 3805
3801 cfq_put_async_queues(cfqd); 3806 cfq_put_async_queues(cfqd);
3802 cfq_release_cfq_groups(cfqd); 3807 cfq_release_cfq_groups(cfqd);
3803 cfq_blkiocg_del_blkio_group(&cfqd->root_group.blkg); 3808 cfq_blkiocg_del_blkio_group(&cfqd->root_group.blkg);
3804 3809
3805 spin_unlock_irq(q->queue_lock); 3810 spin_unlock_irq(q->queue_lock);
3806 3811
3807 cfq_shutdown_timer_wq(cfqd); 3812 cfq_shutdown_timer_wq(cfqd);
3808 3813
3809 spin_lock(&cic_index_lock); 3814 spin_lock(&cic_index_lock);
3810 ida_remove(&cic_index_ida, cfqd->cic_index); 3815 ida_remove(&cic_index_ida, cfqd->cic_index);
3811 spin_unlock(&cic_index_lock); 3816 spin_unlock(&cic_index_lock);
3812 3817
3813 /* Wait for cfqg->blkg->key accessors to exit their grace periods. */ 3818 /* Wait for cfqg->blkg->key accessors to exit their grace periods. */
3814 call_rcu(&cfqd->rcu, cfq_cfqd_free); 3819 call_rcu(&cfqd->rcu, cfq_cfqd_free);
3815 } 3820 }
3816 3821
3817 static int cfq_alloc_cic_index(void) 3822 static int cfq_alloc_cic_index(void)
3818 { 3823 {
3819 int index, error; 3824 int index, error;
3820 3825
3821 do { 3826 do {
3822 if (!ida_pre_get(&cic_index_ida, GFP_KERNEL)) 3827 if (!ida_pre_get(&cic_index_ida, GFP_KERNEL))
3823 return -ENOMEM; 3828 return -ENOMEM;
3824 3829
3825 spin_lock(&cic_index_lock); 3830 spin_lock(&cic_index_lock);
3826 error = ida_get_new(&cic_index_ida, &index); 3831 error = ida_get_new(&cic_index_ida, &index);
3827 spin_unlock(&cic_index_lock); 3832 spin_unlock(&cic_index_lock);
3828 if (error && error != -EAGAIN) 3833 if (error && error != -EAGAIN)
3829 return error; 3834 return error;
3830 } while (error); 3835 } while (error);
3831 3836
3832 return index; 3837 return index;
3833 } 3838 }
3834 3839
3835 static void *cfq_init_queue(struct request_queue *q) 3840 static void *cfq_init_queue(struct request_queue *q)
3836 { 3841 {
3837 struct cfq_data *cfqd; 3842 struct cfq_data *cfqd;
3838 int i, j; 3843 int i, j;
3839 struct cfq_group *cfqg; 3844 struct cfq_group *cfqg;
3840 struct cfq_rb_root *st; 3845 struct cfq_rb_root *st;
3841 3846
3842 i = cfq_alloc_cic_index(); 3847 i = cfq_alloc_cic_index();
3843 if (i < 0) 3848 if (i < 0)
3844 return NULL; 3849 return NULL;
3845 3850
3846 cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); 3851 cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node);
3847 if (!cfqd) 3852 if (!cfqd)
3848 return NULL; 3853 return NULL;
3849 3854
3850 cfqd->cic_index = i; 3855 cfqd->cic_index = i;
3851 3856
3852 /* Init root service tree */ 3857 /* Init root service tree */
3853 cfqd->grp_service_tree = CFQ_RB_ROOT; 3858 cfqd->grp_service_tree = CFQ_RB_ROOT;
3854 3859
3855 /* Init root group */ 3860 /* Init root group */
3856 cfqg = &cfqd->root_group; 3861 cfqg = &cfqd->root_group;
3857 for_each_cfqg_st(cfqg, i, j, st) 3862 for_each_cfqg_st(cfqg, i, j, st)
3858 *st = CFQ_RB_ROOT; 3863 *st = CFQ_RB_ROOT;
3859 RB_CLEAR_NODE(&cfqg->rb_node); 3864 RB_CLEAR_NODE(&cfqg->rb_node);
3860 3865
3861 /* Give preference to root group over other groups */ 3866 /* Give preference to root group over other groups */
3862 cfqg->weight = 2*BLKIO_WEIGHT_DEFAULT; 3867 cfqg->weight = 2*BLKIO_WEIGHT_DEFAULT;
3863 3868
3864 #ifdef CONFIG_CFQ_GROUP_IOSCHED 3869 #ifdef CONFIG_CFQ_GROUP_IOSCHED
3865 /* 3870 /*
3866 * Take a reference to root group which we never drop. This is just 3871 * Take a reference to root group which we never drop. This is just
3867 * to make sure that cfq_put_cfqg() does not try to kfree root group 3872 * to make sure that cfq_put_cfqg() does not try to kfree root group
3868 */ 3873 */
3869 atomic_set(&cfqg->ref, 1); 3874 atomic_set(&cfqg->ref, 1);
3870 rcu_read_lock(); 3875 rcu_read_lock();
3871 cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, 3876 cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg,
3872 (void *)cfqd, 0); 3877 (void *)cfqd, 0);
3873 rcu_read_unlock(); 3878 rcu_read_unlock();
3874 #endif 3879 #endif
3875 /* 3880 /*
3876 * Not strictly needed (since RB_ROOT just clears the node and we 3881 * Not strictly needed (since RB_ROOT just clears the node and we
3877 * zeroed cfqd on alloc), but better be safe in case someone decides 3882 * zeroed cfqd on alloc), but better be safe in case someone decides
3878 * to add magic to the rb code 3883 * to add magic to the rb code
3879 */ 3884 */
3880 for (i = 0; i < CFQ_PRIO_LISTS; i++) 3885 for (i = 0; i < CFQ_PRIO_LISTS; i++)
3881 cfqd->prio_trees[i] = RB_ROOT; 3886 cfqd->prio_trees[i] = RB_ROOT;
3882 3887
3883 /* 3888 /*
3884 * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues. 3889 * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues.
3885 * Grab a permanent reference to it, so that the normal code flow 3890 * Grab a permanent reference to it, so that the normal code flow
3886 * will not attempt to free it. 3891 * will not attempt to free it.
3887 */ 3892 */
3888 cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); 3893 cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0);
3889 atomic_inc(&cfqd->oom_cfqq.ref); 3894 atomic_inc(&cfqd->oom_cfqq.ref);
3890 cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group); 3895 cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group);
3891 3896
3892 INIT_LIST_HEAD(&cfqd->cic_list); 3897 INIT_LIST_HEAD(&cfqd->cic_list);
3893 3898
3894 cfqd->queue = q; 3899 cfqd->queue = q;
3895 3900
3896 init_timer(&cfqd->idle_slice_timer); 3901 init_timer(&cfqd->idle_slice_timer);
3897 cfqd->idle_slice_timer.function = cfq_idle_slice_timer; 3902 cfqd->idle_slice_timer.function = cfq_idle_slice_timer;
3898 cfqd->idle_slice_timer.data = (unsigned long) cfqd; 3903 cfqd->idle_slice_timer.data = (unsigned long) cfqd;
3899 3904
3900 INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); 3905 INIT_WORK(&cfqd->unplug_work, cfq_kick_queue);
3901 3906
3902 cfqd->cfq_quantum = cfq_quantum; 3907 cfqd->cfq_quantum = cfq_quantum;
3903 cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; 3908 cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0];
3904 cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; 3909 cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1];
3905 cfqd->cfq_back_max = cfq_back_max; 3910 cfqd->cfq_back_max = cfq_back_max;
3906 cfqd->cfq_back_penalty = cfq_back_penalty; 3911 cfqd->cfq_back_penalty = cfq_back_penalty;
3907 cfqd->cfq_slice[0] = cfq_slice_async; 3912 cfqd->cfq_slice[0] = cfq_slice_async;
3908 cfqd->cfq_slice[1] = cfq_slice_sync; 3913 cfqd->cfq_slice[1] = cfq_slice_sync;
3909 cfqd->cfq_slice_async_rq = cfq_slice_async_rq; 3914 cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
3910 cfqd->cfq_slice_idle = cfq_slice_idle; 3915 cfqd->cfq_slice_idle = cfq_slice_idle;
3911 cfqd->cfq_group_idle = cfq_group_idle; 3916 cfqd->cfq_group_idle = cfq_group_idle;
3912 cfqd->cfq_latency = 1; 3917 cfqd->cfq_latency = 1;
3913 cfqd->cfq_group_isolation = 0; 3918 cfqd->cfq_group_isolation = 0;
3914 cfqd->hw_tag = -1; 3919 cfqd->hw_tag = -1;
3915 /* 3920 /*
3916 * we optimistically start assuming sync ops weren't delayed in last 3921 * we optimistically start assuming sync ops weren't delayed in last
3917 * second, in order to have larger depth for async operations. 3922 * second, in order to have larger depth for async operations.
3918 */ 3923 */
3919 cfqd->last_delayed_sync = jiffies - HZ; 3924 cfqd->last_delayed_sync = jiffies - HZ;
3920 return cfqd; 3925 return cfqd;
3921 } 3926 }
3922 3927
3923 static void cfq_slab_kill(void) 3928 static void cfq_slab_kill(void)
3924 { 3929 {
3925 /* 3930 /*
3926 * Caller already ensured that pending RCU callbacks are completed, 3931 * Caller already ensured that pending RCU callbacks are completed,
3927 * so we should have no busy allocations at this point. 3932 * so we should have no busy allocations at this point.
3928 */ 3933 */
3929 if (cfq_pool) 3934 if (cfq_pool)
3930 kmem_cache_destroy(cfq_pool); 3935 kmem_cache_destroy(cfq_pool);
3931 if (cfq_ioc_pool) 3936 if (cfq_ioc_pool)
3932 kmem_cache_destroy(cfq_ioc_pool); 3937 kmem_cache_destroy(cfq_ioc_pool);
3933 } 3938 }
3934 3939
3935 static int __init cfq_slab_setup(void) 3940 static int __init cfq_slab_setup(void)
3936 { 3941 {
3937 cfq_pool = KMEM_CACHE(cfq_queue, 0); 3942 cfq_pool = KMEM_CACHE(cfq_queue, 0);
3938 if (!cfq_pool) 3943 if (!cfq_pool)
3939 goto fail; 3944 goto fail;
3940 3945
3941 cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0); 3946 cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0);
3942 if (!cfq_ioc_pool) 3947 if (!cfq_ioc_pool)
3943 goto fail; 3948 goto fail;
3944 3949
3945 return 0; 3950 return 0;
3946 fail: 3951 fail:
3947 cfq_slab_kill(); 3952 cfq_slab_kill();
3948 return -ENOMEM; 3953 return -ENOMEM;
3949 } 3954 }
3950 3955
3951 /* 3956 /*
3952 * sysfs parts below --> 3957 * sysfs parts below -->
3953 */ 3958 */
3954 static ssize_t 3959 static ssize_t
3955 cfq_var_show(unsigned int var, char *page) 3960 cfq_var_show(unsigned int var, char *page)
3956 { 3961 {
3957 return sprintf(page, "%d\n", var); 3962 return sprintf(page, "%d\n", var);
3958 } 3963 }
3959 3964
3960 static ssize_t 3965 static ssize_t
3961 cfq_var_store(unsigned int *var, const char *page, size_t count) 3966 cfq_var_store(unsigned int *var, const char *page, size_t count)
3962 { 3967 {
3963 char *p = (char *) page; 3968 char *p = (char *) page;
3964 3969
3965 *var = simple_strtoul(p, &p, 10); 3970 *var = simple_strtoul(p, &p, 10);
3966 return count; 3971 return count;
3967 } 3972 }
3968 3973
3969 #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ 3974 #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
3970 static ssize_t __FUNC(struct elevator_queue *e, char *page) \ 3975 static ssize_t __FUNC(struct elevator_queue *e, char *page) \
3971 { \ 3976 { \
3972 struct cfq_data *cfqd = e->elevator_data; \ 3977 struct cfq_data *cfqd = e->elevator_data; \
3973 unsigned int __data = __VAR; \ 3978 unsigned int __data = __VAR; \
3974 if (__CONV) \ 3979 if (__CONV) \
3975 __data = jiffies_to_msecs(__data); \ 3980 __data = jiffies_to_msecs(__data); \
3976 return cfq_var_show(__data, (page)); \ 3981 return cfq_var_show(__data, (page)); \
3977 } 3982 }
3978 SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); 3983 SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0);
3979 SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); 3984 SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1);
3980 SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1); 3985 SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1);
3981 SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); 3986 SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0);
3982 SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); 3987 SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0);
3983 SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); 3988 SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1);
3984 SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1); 3989 SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1);
3985 SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); 3990 SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1);
3986 SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); 3991 SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1);
3987 SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); 3992 SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
3988 SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); 3993 SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0);
3989 SHOW_FUNCTION(cfq_group_isolation_show, cfqd->cfq_group_isolation, 0); 3994 SHOW_FUNCTION(cfq_group_isolation_show, cfqd->cfq_group_isolation, 0);
3990 #undef SHOW_FUNCTION 3995 #undef SHOW_FUNCTION
3991 3996
3992 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ 3997 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
3993 static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ 3998 static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
3994 { \ 3999 { \
3995 struct cfq_data *cfqd = e->elevator_data; \ 4000 struct cfq_data *cfqd = e->elevator_data; \
3996 unsigned int __data; \ 4001 unsigned int __data; \
3997 int ret = cfq_var_store(&__data, (page), count); \ 4002 int ret = cfq_var_store(&__data, (page), count); \
3998 if (__data < (MIN)) \ 4003 if (__data < (MIN)) \
3999 __data = (MIN); \ 4004 __data = (MIN); \
4000 else if (__data > (MAX)) \ 4005 else if (__data > (MAX)) \
4001 __data = (MAX); \ 4006 __data = (MAX); \
4002 if (__CONV) \ 4007 if (__CONV) \
4003 *(__PTR) = msecs_to_jiffies(__data); \ 4008 *(__PTR) = msecs_to_jiffies(__data); \
4004 else \ 4009 else \
4005 *(__PTR) = __data; \ 4010 *(__PTR) = __data; \
4006 return ret; \ 4011 return ret; \
4007 } 4012 }
4008 STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); 4013 STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0);
4009 STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, 4014 STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1,
4010 UINT_MAX, 1); 4015 UINT_MAX, 1);
4011 STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, 4016 STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1,
4012 UINT_MAX, 1); 4017 UINT_MAX, 1);
4013 STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0); 4018 STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0);
4014 STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, 4019 STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1,
4015 UINT_MAX, 0); 4020 UINT_MAX, 0);
4016 STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); 4021 STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1);
4017 STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1); 4022 STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1);
4018 STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); 4023 STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1);
4019 STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1); 4024 STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1);
4020 STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, 4025 STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1,
4021 UINT_MAX, 0); 4026 UINT_MAX, 0);
4022 STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); 4027 STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0);
4023 STORE_FUNCTION(cfq_group_isolation_store, &cfqd->cfq_group_isolation, 0, 1, 0); 4028 STORE_FUNCTION(cfq_group_isolation_store, &cfqd->cfq_group_isolation, 0, 1, 0);
4024 #undef STORE_FUNCTION 4029 #undef STORE_FUNCTION
4025 4030
4026 #define CFQ_ATTR(name) \ 4031 #define CFQ_ATTR(name) \
4027 __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) 4032 __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store)
4028 4033
4029 static struct elv_fs_entry cfq_attrs[] = { 4034 static struct elv_fs_entry cfq_attrs[] = {
4030 CFQ_ATTR(quantum), 4035 CFQ_ATTR(quantum),
4031 CFQ_ATTR(fifo_expire_sync), 4036 CFQ_ATTR(fifo_expire_sync),
4032 CFQ_ATTR(fifo_expire_async), 4037 CFQ_ATTR(fifo_expire_async),
4033 CFQ_ATTR(back_seek_max), 4038 CFQ_ATTR(back_seek_max),
4034 CFQ_ATTR(back_seek_penalty), 4039 CFQ_ATTR(back_seek_penalty),
4035 CFQ_ATTR(slice_sync), 4040 CFQ_ATTR(slice_sync),
4036 CFQ_ATTR(slice_async), 4041 CFQ_ATTR(slice_async),
4037 CFQ_ATTR(slice_async_rq), 4042 CFQ_ATTR(slice_async_rq),
4038 CFQ_ATTR(slice_idle), 4043 CFQ_ATTR(slice_idle),
4039 CFQ_ATTR(group_idle), 4044 CFQ_ATTR(group_idle),
4040 CFQ_ATTR(low_latency), 4045 CFQ_ATTR(low_latency),
4041 CFQ_ATTR(group_isolation), 4046 CFQ_ATTR(group_isolation),
4042 __ATTR_NULL 4047 __ATTR_NULL
4043 }; 4048 };
4044 4049
4045 static struct elevator_type iosched_cfq = { 4050 static struct elevator_type iosched_cfq = {
4046 .ops = { 4051 .ops = {
4047 .elevator_merge_fn = cfq_merge, 4052 .elevator_merge_fn = cfq_merge,
4048 .elevator_merged_fn = cfq_merged_request, 4053 .elevator_merged_fn = cfq_merged_request,
4049 .elevator_merge_req_fn = cfq_merged_requests, 4054 .elevator_merge_req_fn = cfq_merged_requests,
4050 .elevator_allow_merge_fn = cfq_allow_merge, 4055 .elevator_allow_merge_fn = cfq_allow_merge,
4051 .elevator_bio_merged_fn = cfq_bio_merged, 4056 .elevator_bio_merged_fn = cfq_bio_merged,
4052 .elevator_dispatch_fn = cfq_dispatch_requests, 4057 .elevator_dispatch_fn = cfq_dispatch_requests,
4053 .elevator_add_req_fn = cfq_insert_request, 4058 .elevator_add_req_fn = cfq_insert_request,
4054 .elevator_activate_req_fn = cfq_activate_request, 4059 .elevator_activate_req_fn = cfq_activate_request,
4055 .elevator_deactivate_req_fn = cfq_deactivate_request, 4060 .elevator_deactivate_req_fn = cfq_deactivate_request,
4056 .elevator_queue_empty_fn = cfq_queue_empty, 4061 .elevator_queue_empty_fn = cfq_queue_empty,
4057 .elevator_completed_req_fn = cfq_completed_request, 4062 .elevator_completed_req_fn = cfq_completed_request,
4058 .elevator_former_req_fn = elv_rb_former_request, 4063 .elevator_former_req_fn = elv_rb_former_request,
4059 .elevator_latter_req_fn = elv_rb_latter_request, 4064 .elevator_latter_req_fn = elv_rb_latter_request,
4060 .elevator_set_req_fn = cfq_set_request, 4065 .elevator_set_req_fn = cfq_set_request,
4061 .elevator_put_req_fn = cfq_put_request, 4066 .elevator_put_req_fn = cfq_put_request,
4062 .elevator_may_queue_fn = cfq_may_queue, 4067 .elevator_may_queue_fn = cfq_may_queue,
4063 .elevator_init_fn = cfq_init_queue, 4068 .elevator_init_fn = cfq_init_queue,
4064 .elevator_exit_fn = cfq_exit_queue, 4069 .elevator_exit_fn = cfq_exit_queue,
4065 .trim = cfq_free_io_context, 4070 .trim = cfq_free_io_context,
4066 }, 4071 },
4067 .elevator_attrs = cfq_attrs, 4072 .elevator_attrs = cfq_attrs,
4068 .elevator_name = "cfq", 4073 .elevator_name = "cfq",
4069 .elevator_owner = THIS_MODULE, 4074 .elevator_owner = THIS_MODULE,
4070 }; 4075 };
4071 4076
4072 #ifdef CONFIG_CFQ_GROUP_IOSCHED 4077 #ifdef CONFIG_CFQ_GROUP_IOSCHED
4073 static struct blkio_policy_type blkio_policy_cfq = { 4078 static struct blkio_policy_type blkio_policy_cfq = {
4074 .ops = { 4079 .ops = {
4075 .blkio_unlink_group_fn = cfq_unlink_blkio_group, 4080 .blkio_unlink_group_fn = cfq_unlink_blkio_group,
4076 .blkio_update_group_weight_fn = cfq_update_blkio_group_weight, 4081 .blkio_update_group_weight_fn = cfq_update_blkio_group_weight,
4077 }, 4082 },
4078 }; 4083 };
4079 #else 4084 #else
4080 static struct blkio_policy_type blkio_policy_cfq; 4085 static struct blkio_policy_type blkio_policy_cfq;
4081 #endif 4086 #endif
4082 4087
4083 static int __init cfq_init(void) 4088 static int __init cfq_init(void)
4084 { 4089 {
4085 /* 4090 /*
4086 * could be 0 on HZ < 1000 setups 4091 * could be 0 on HZ < 1000 setups
4087 */ 4092 */
4088 if (!cfq_slice_async) 4093 if (!cfq_slice_async)
4089 cfq_slice_async = 1; 4094 cfq_slice_async = 1;
4090 if (!cfq_slice_idle) 4095 if (!cfq_slice_idle)
4091 cfq_slice_idle = 1; 4096 cfq_slice_idle = 1;
4092 4097
4093 #ifdef CONFIG_CFQ_GROUP_IOSCHED 4098 #ifdef CONFIG_CFQ_GROUP_IOSCHED
4094 if (!cfq_group_idle) 4099 if (!cfq_group_idle)
4095 cfq_group_idle = 1; 4100 cfq_group_idle = 1;
4096 #else 4101 #else
4097 cfq_group_idle = 0; 4102 cfq_group_idle = 0;
4098 #endif 4103 #endif
4099 if (cfq_slab_setup()) 4104 if (cfq_slab_setup())
4100 return -ENOMEM; 4105 return -ENOMEM;
4101 4106
4102 elv_register(&iosched_cfq); 4107 elv_register(&iosched_cfq);
4103 blkio_policy_register(&blkio_policy_cfq); 4108 blkio_policy_register(&blkio_policy_cfq);
4104 4109
4105 return 0; 4110 return 0;
4106 } 4111 }
4107 4112
4108 static void __exit cfq_exit(void) 4113 static void __exit cfq_exit(void)
4109 { 4114 {
4110 DECLARE_COMPLETION_ONSTACK(all_gone); 4115 DECLARE_COMPLETION_ONSTACK(all_gone);
4111 blkio_policy_unregister(&blkio_policy_cfq); 4116 blkio_policy_unregister(&blkio_policy_cfq);
4112 elv_unregister(&iosched_cfq); 4117 elv_unregister(&iosched_cfq);
4113 ioc_gone = &all_gone; 4118 ioc_gone = &all_gone;
4114 /* ioc_gone's update must be visible before reading ioc_count */ 4119 /* ioc_gone's update must be visible before reading ioc_count */
4115 smp_wmb(); 4120 smp_wmb();
4116 4121
4117 /* 4122 /*
4118 * this also protects us from entering cfq_slab_kill() with 4123 * this also protects us from entering cfq_slab_kill() with
4119 * pending RCU callbacks 4124 * pending RCU callbacks
4120 */ 4125 */
4121 if (elv_ioc_count_read(cfq_ioc_count)) 4126 if (elv_ioc_count_read(cfq_ioc_count))
4122 wait_for_completion(&all_gone); 4127 wait_for_completion(&all_gone);
4123 ida_destroy(&cic_index_ida); 4128 ida_destroy(&cic_index_ida);
4124 cfq_slab_kill(); 4129 cfq_slab_kill();
4125 } 4130 }
4126 4131
4127 module_init(cfq_init); 4132 module_init(cfq_init);
4128 module_exit(cfq_exit); 4133 module_exit(cfq_exit);
4129 4134
4130 MODULE_AUTHOR("Jens Axboe"); 4135 MODULE_AUTHOR("Jens Axboe");
4131 MODULE_LICENSE("GPL"); 4136 MODULE_LICENSE("GPL");
4132 MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); 4137 MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler");
4133 4138