Blame view
block/blk-cgroup.c
47.9 KB
3dcf60bcb block: add SPDX t... |
1 |
// SPDX-License-Identifier: GPL-2.0 |
31e4c28d9 blkio: Introduce ... |
2 3 4 5 6 7 8 9 10 11 12 |
/* * Common Block IO controller cgroup interface * * Based on ideas and code from CFQ, CFS and BFQ: * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> * * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> * Paolo Valente <paolo.valente@unimore.it> * * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com> * Nauman Rafique <nauman@google.com> |
e48453c38 block, cgroup: im... |
13 14 15 16 |
* * For policy-specific per-blkcg data: * Copyright (C) 2015 Paolo Valente <paolo.valente@unimore.it> * Arianna Avanzini <avanzini.arianna@gmail.com> |
31e4c28d9 blkio: Introduce ... |
17 18 |
*/ #include <linux/ioprio.h> |
220841906 blkio: Export dis... |
19 |
#include <linux/kdev_t.h> |
9d6a986c0 blkio: Export som... |
20 |
#include <linux/module.h> |
174cd4b1e sched/headers: Pr... |
21 |
#include <linux/sched/signal.h> |
accee7854 block: include li... |
22 |
#include <linux/err.h> |
9195291e5 blkio: Increment ... |
23 |
#include <linux/blkdev.h> |
52ebea749 writeback: make b... |
24 |
#include <linux/backing-dev.h> |
5a0e3ad6a include cleanup: ... |
25 |
#include <linux/slab.h> |
34d0f179d io-controller: Ad... |
26 |
#include <linux/genhd.h> |
72e06c255 blkcg: shoot down... |
27 |
#include <linux/delay.h> |
9a9e8a26d blkcg: add blkcg->id |
28 |
#include <linux/atomic.h> |
36aa9e5f5 blkcg: move body ... |
29 |
#include <linux/ctype.h> |
eea8f41cc blkcg: move block... |
30 |
#include <linux/blk-cgroup.h> |
d09d8df3a blkcg: add generi... |
31 |
#include <linux/tracehook.h> |
fd112c746 blk-cgroup: turn ... |
32 |
#include <linux/psi.h> |
5efd61135 blkcg: add blkcg_... |
33 |
#include "blk.h" |
3e2520668 blkio: Implement ... |
34 |
|
84c124da9 blkio: Changes to... |
35 |
#define MAX_KEY_LEN 100 |
838f13bf4 blkcg: allow blkc... |
36 37 38 39 40 41 42 43 |
/* * blkcg_pol_mutex protects blkcg_policy[] and policy [de]activation. * blkcg_pol_register_mutex nests outside of it and synchronizes entire * policy [un]register operations including cgroup file additions / * removals. Putting cgroup file registration outside blkcg_pol_mutex * allows grabbing it from cgroup callbacks. */ static DEFINE_MUTEX(blkcg_pol_register_mutex); |
bc0d6501a blkcg: kill blkio... |
44 |
static DEFINE_MUTEX(blkcg_pol_mutex); |
923adde1b blkcg: clear all ... |
45 |
|
e48453c38 block, cgroup: im... |
46 |
struct blkcg blkcg_root; |
3c798398e blkcg: mass renam... |
47 |
EXPORT_SYMBOL_GPL(blkcg_root); |
9d6a986c0 blkio: Export som... |
48 |
|
496d5e756 blkcg: add blkcg_... |
49 |
struct cgroup_subsys_state * const blkcg_root_css = &blkcg_root.css; |
9b0eb69b7 cgroup, blkcg: Pr... |
50 |
EXPORT_SYMBOL_GPL(blkcg_root_css); |
496d5e756 blkcg: add blkcg_... |
51 |
|
3c798398e blkcg: mass renam... |
52 |
static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS]; |
035d10b2f blkcg: add blkio_... |
53 |
|
7876f930d blkcg: implement ... |
54 |
static LIST_HEAD(all_blkcgs); /* protected by blkcg_pol_mutex */ |
07b0fdecb blkcg: allow blkc... |
55 |
bool blkcg_debug_stats = false; |
d3f77dfdc blkcg: implement ... |
56 |
static struct workqueue_struct *blkcg_punt_bio_wq; |
903d23f0a blk-cgroup: allow... |
57 |
|
a2b1693ba blkcg: implement ... |
58 |
static bool blkcg_policy_enabled(struct request_queue *q, |
3c798398e blkcg: mass renam... |
59 |
const struct blkcg_policy *pol) |
a2b1693ba blkcg: implement ... |
60 61 62 |
{ return pol && test_bit(pol->plid, q->blkcg_pols); } |
0381411e4 blkcg: let blkcg ... |
63 64 65 66 67 68 |
/** * blkg_free - free a blkg * @blkg: blkg to free * * Free @blkg which may be partially allocated. */ |
3c798398e blkcg: mass renam... |
69 |
static void blkg_free(struct blkcg_gq *blkg) |
0381411e4 blkcg: let blkcg ... |
70 |
{ |
e8989fae3 blkcg: unify blkg... |
71 |
int i; |
549d3aa87 blkcg: make blkg-... |
72 73 74 |
if (!blkg) return; |
db6136703 blkcg: invoke blk... |
75 |
for (i = 0; i < BLKCG_MAX_POLS; i++) |
001bea73e blkcg: replace bl... |
76 77 |
if (blkg->pd[i]) blkcg_policy[i]->pd_free_fn(blkg->pd[i]); |
e8989fae3 blkcg: unify blkg... |
78 |
|
77ea73388 blkcg: move io_se... |
79 80 |
blkg_rwstat_exit(&blkg->stat_ios); blkg_rwstat_exit(&blkg->stat_bytes); |
ef069b97f blkcg: perpcu_ref... |
81 |
percpu_ref_exit(&blkg->refcnt); |
549d3aa87 blkcg: make blkg-... |
82 |
kfree(blkg); |
0381411e4 blkcg: let blkcg ... |
83 |
} |
7fcf2b033 blkcg: change blk... |
84 85 86 |
static void __blkg_release(struct rcu_head *rcu) { struct blkcg_gq *blkg = container_of(rcu, struct blkcg_gq, rcu_head); |
d3f77dfdc blkcg: implement ... |
87 |
WARN_ON(!bio_list_empty(&blkg->async_bios)); |
7fcf2b033 blkcg: change blk... |
88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 |
/* release the blkcg and parent blkg refs this blkg has been holding */ css_put(&blkg->blkcg->css); if (blkg->parent) blkg_put(blkg->parent); wb_congested_put(blkg->wb_congested); blkg_free(blkg); } /* * A group is RCU protected, but having an rcu lock does not mean that one * can access all the fields of blkg and assume these are valid. For * example, don't try to follow throtl_data and request queue links. * * Having a reference to blkg under an rcu allows accesses to only values * local to groups like group stats and group rate limits. */ static void blkg_release(struct percpu_ref *ref) { struct blkcg_gq *blkg = container_of(ref, struct blkcg_gq, refcnt); call_rcu(&blkg->rcu_head, __blkg_release); } |
d3f77dfdc blkcg: implement ... |
112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 |
static void blkg_async_bio_workfn(struct work_struct *work) { struct blkcg_gq *blkg = container_of(work, struct blkcg_gq, async_bio_work); struct bio_list bios = BIO_EMPTY_LIST; struct bio *bio; /* as long as there are pending bios, @blkg can't go away */ spin_lock_bh(&blkg->async_bio_lock); bio_list_merge(&bios, &blkg->async_bios); bio_list_init(&blkg->async_bios); spin_unlock_bh(&blkg->async_bio_lock); while ((bio = bio_list_pop(&bios))) submit_bio(bio); } |
0381411e4 blkcg: let blkcg ... |
128 129 130 131 |
/** * blkg_alloc - allocate a blkg * @blkcg: block cgroup the new blkg is associated with * @q: request_queue the new blkg is associated with |
159749937 blkcg: make root ... |
132 |
* @gfp_mask: allocation mask to use |
0381411e4 blkcg: let blkcg ... |
133 |
* |
e8989fae3 blkcg: unify blkg... |
134 |
* Allocate a new blkg assocating @blkcg and @q. |
0381411e4 blkcg: let blkcg ... |
135 |
*/ |
159749937 blkcg: make root ... |
136 137 |
static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q, gfp_t gfp_mask) |
0381411e4 blkcg: let blkcg ... |
138 |
{ |
3c798398e blkcg: mass renam... |
139 |
struct blkcg_gq *blkg; |
e8989fae3 blkcg: unify blkg... |
140 |
int i; |
0381411e4 blkcg: let blkcg ... |
141 142 |
/* alloc and init base part */ |
159749937 blkcg: make root ... |
143 |
blkg = kzalloc_node(sizeof(*blkg), gfp_mask, q->node); |
0381411e4 blkcg: let blkcg ... |
144 145 |
if (!blkg) return NULL; |
ef069b97f blkcg: perpcu_ref... |
146 147 |
if (percpu_ref_init(&blkg->refcnt, blkg_release, 0, gfp_mask)) goto err_free; |
77ea73388 blkcg: move io_se... |
148 149 150 |
if (blkg_rwstat_init(&blkg->stat_bytes, gfp_mask) || blkg_rwstat_init(&blkg->stat_ios, gfp_mask)) goto err_free; |
c875f4d02 blkcg: drop unnec... |
151 |
blkg->q = q; |
e8989fae3 blkcg: unify blkg... |
152 |
INIT_LIST_HEAD(&blkg->q_node); |
d3f77dfdc blkcg: implement ... |
153 154 155 |
spin_lock_init(&blkg->async_bio_lock); bio_list_init(&blkg->async_bios); INIT_WORK(&blkg->async_bio_work, blkg_async_bio_workfn); |
0381411e4 blkcg: let blkcg ... |
156 |
blkg->blkcg = blkcg; |
0381411e4 blkcg: let blkcg ... |
157 |
|
8bd435b30 blkcg: remove sta... |
158 |
for (i = 0; i < BLKCG_MAX_POLS; i++) { |
3c798398e blkcg: mass renam... |
159 |
struct blkcg_policy *pol = blkcg_policy[i]; |
e8989fae3 blkcg: unify blkg... |
160 |
struct blkg_policy_data *pd; |
0381411e4 blkcg: let blkcg ... |
161 |
|
a2b1693ba blkcg: implement ... |
162 |
if (!blkcg_policy_enabled(q, pol)) |
e8989fae3 blkcg: unify blkg... |
163 164 165 |
continue; /* alloc per-policy data and attach it to blkg */ |
cf09a8ee1 blkcg: pass @q an... |
166 |
pd = pol->pd_alloc_fn(gfp_mask, q, blkcg); |
a051661ca blkcg: implement ... |
167 168 |
if (!pd) goto err_free; |
549d3aa87 blkcg: make blkg-... |
169 |
|
e8989fae3 blkcg: unify blkg... |
170 171 |
blkg->pd[i] = pd; pd->blkg = blkg; |
b276a876a blkcg: add blkg_p... |
172 |
pd->plid = i; |
e8989fae3 blkcg: unify blkg... |
173 |
} |
0381411e4 blkcg: let blkcg ... |
174 |
return blkg; |
a051661ca blkcg: implement ... |
175 176 177 178 |
err_free: blkg_free(blkg); return NULL; |
0381411e4 blkcg: let blkcg ... |
179 |
} |
24f290466 blkcg: inline [__... |
180 181 |
struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg, struct request_queue *q, bool update_hint) |
80fd99792 blkcg: make sure ... |
182 |
{ |
3c798398e blkcg: mass renam... |
183 |
struct blkcg_gq *blkg; |
80fd99792 blkcg: make sure ... |
184 |
|
a637120e4 blkcg: use radix ... |
185 |
/* |
86cde6b62 blkcg: reorganize... |
186 187 188 189 |
* Hint didn't match. Look up from the radix tree. Note that the * hint can only be updated under queue_lock as otherwise @blkg * could have already been removed from blkg_tree. The caller is * responsible for grabbing queue_lock if @update_hint. |
a637120e4 blkcg: use radix ... |
190 191 |
*/ blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id); |
86cde6b62 blkcg: reorganize... |
192 193 |
if (blkg && blkg->q == q) { if (update_hint) { |
0d945c1f9 block: remove the... |
194 |
lockdep_assert_held(&q->queue_lock); |
86cde6b62 blkcg: reorganize... |
195 196 |
rcu_assign_pointer(blkcg->blkg_hint, blkg); } |
a637120e4 blkcg: use radix ... |
197 |
return blkg; |
86cde6b62 blkcg: reorganize... |
198 |
} |
a637120e4 blkcg: use radix ... |
199 |
|
80fd99792 blkcg: make sure ... |
200 201 |
return NULL; } |
ae1188963 blkcg: consolidat... |
202 |
EXPORT_SYMBOL_GPL(blkg_lookup_slowpath); |
80fd99792 blkcg: make sure ... |
203 |
|
159749937 blkcg: make root ... |
204 |
/* |
d708f0d50 Revert "blkcg: al... |
205 206 |
* If @new_blkg is %NULL, this function tries to allocate a new one as * necessary using %GFP_NOWAIT. @new_blkg is always consumed on return. |
159749937 blkcg: make root ... |
207 |
*/ |
86cde6b62 blkcg: reorganize... |
208 |
static struct blkcg_gq *blkg_create(struct blkcg *blkcg, |
d708f0d50 Revert "blkcg: al... |
209 210 |
struct request_queue *q, struct blkcg_gq *new_blkg) |
5624a4e44 blk-throttle: Mak... |
211 |
{ |
d708f0d50 Revert "blkcg: al... |
212 |
struct blkcg_gq *blkg; |
ce7acfeaf writeback, blkcg:... |
213 |
struct bdi_writeback_congested *wb_congested; |
f427d9096 blkcg: implement ... |
214 |
int i, ret; |
5624a4e44 blk-throttle: Mak... |
215 |
|
cd1604fab blkcg: factor out... |
216 |
WARN_ON_ONCE(!rcu_read_lock_held()); |
0d945c1f9 block: remove the... |
217 |
lockdep_assert_held(&q->queue_lock); |
cd1604fab blkcg: factor out... |
218 |
|
0273ac349 blkcg: handle dyi... |
219 220 221 222 223 |
/* request_queue is dying, do not create/recreate a blkg */ if (blk_queue_dying(q)) { ret = -ENODEV; goto err_free_blkg; } |
7ee9c5620 blkcg: let blkio_... |
224 |
/* blkg holds a reference to blkcg */ |
ec903c0c8 cgroup: rename cs... |
225 |
if (!css_tryget_online(&blkcg->css)) { |
20386ce01 blkcg: refine err... |
226 |
ret = -ENODEV; |
93e6d5d8f blkcg: cosmetic u... |
227 |
goto err_free_blkg; |
159749937 blkcg: make root ... |
228 |
} |
cd1604fab blkcg: factor out... |
229 |
|
dc3b17cc8 block: Use pointe... |
230 |
wb_congested = wb_congested_get_create(q->backing_dev_info, |
d708f0d50 Revert "blkcg: al... |
231 232 233 |
blkcg->css.id, GFP_NOWAIT | __GFP_NOWARN); if (!wb_congested) { |
ce7acfeaf writeback, blkcg:... |
234 |
ret = -ENOMEM; |
d708f0d50 Revert "blkcg: al... |
235 |
goto err_put_css; |
ce7acfeaf writeback, blkcg:... |
236 |
} |
d708f0d50 Revert "blkcg: al... |
237 238 239 240 241 242 |
/* allocate */ if (!new_blkg) { new_blkg = blkg_alloc(blkcg, q, GFP_NOWAIT | __GFP_NOWARN); if (unlikely(!new_blkg)) { ret = -ENOMEM; goto err_put_congested; |
159749937 blkcg: make root ... |
243 244 |
} } |
d708f0d50 Revert "blkcg: al... |
245 246 |
blkg = new_blkg; blkg->wb_congested = wb_congested; |
cd1604fab blkcg: factor out... |
247 |
|
db6136703 blkcg: invoke blk... |
248 |
/* link parent */ |
3c5478659 blkcg: make blkcg... |
249 250 251 |
if (blkcg_parent(blkcg)) { blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false); if (WARN_ON_ONCE(!blkg->parent)) { |
20386ce01 blkcg: refine err... |
252 |
ret = -ENODEV; |
d708f0d50 Revert "blkcg: al... |
253 |
goto err_put_congested; |
3c5478659 blkcg: make blkcg... |
254 255 256 |
} blkg_get(blkg->parent); } |
db6136703 blkcg: invoke blk... |
257 258 259 260 261 |
/* invoke per-policy init */ for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkcg_policy *pol = blkcg_policy[i]; if (blkg->pd[i] && pol->pd_init_fn) |
a9520cd6f blkcg: make blkcg... |
262 |
pol->pd_init_fn(blkg->pd[i]); |
db6136703 blkcg: invoke blk... |
263 264 265 |
} /* insert */ |
cd1604fab blkcg: factor out... |
266 |
spin_lock(&blkcg->lock); |
a637120e4 blkcg: use radix ... |
267 268 269 270 |
ret = radix_tree_insert(&blkcg->blkg_tree, q->id, blkg); if (likely(!ret)) { hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); list_add(&blkg->q_node, &q->blkg_list); |
f427d9096 blkcg: implement ... |
271 272 273 274 275 |
for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkcg_policy *pol = blkcg_policy[i]; if (blkg->pd[i] && pol->pd_online_fn) |
a9520cd6f blkcg: make blkcg... |
276 |
pol->pd_online_fn(blkg->pd[i]); |
f427d9096 blkcg: implement ... |
277 |
} |
a637120e4 blkcg: use radix ... |
278 |
} |
f427d9096 blkcg: implement ... |
279 |
blkg->online = true; |
cd1604fab blkcg: factor out... |
280 |
spin_unlock(&blkcg->lock); |
496fb7806 blkcg: fix blkcg-... |
281 |
|
ec13b1d6f blkcg: always cre... |
282 |
if (!ret) |
a637120e4 blkcg: use radix ... |
283 |
return blkg; |
159749937 blkcg: make root ... |
284 |
|
3c5478659 blkcg: make blkcg... |
285 286 287 |
/* @blkg failed fully initialized, use the usual release path */ blkg_put(blkg); return ERR_PTR(ret); |
d708f0d50 Revert "blkcg: al... |
288 289 290 |
err_put_congested: wb_congested_put(wb_congested); err_put_css: |
496fb7806 blkcg: fix blkcg-... |
291 |
css_put(&blkcg->css); |
93e6d5d8f blkcg: cosmetic u... |
292 |
err_free_blkg: |
d708f0d50 Revert "blkcg: al... |
293 |
blkg_free(new_blkg); |
93e6d5d8f blkcg: cosmetic u... |
294 |
return ERR_PTR(ret); |
31e4c28d9 blkio: Introduce ... |
295 |
} |
3c96cb32d blkcg: drop stuff... |
296 |
|
86cde6b62 blkcg: reorganize... |
297 |
/** |
b978962ad blkcg: update blk... |
298 |
* __blkg_lookup_create - lookup blkg, try to create one if not there |
86cde6b62 blkcg: reorganize... |
299 300 301 302 |
* @blkcg: blkcg of interest * @q: request_queue of interest * * Lookup blkg for the @blkcg - @q pair. If it doesn't exist, try to |
3c5478659 blkcg: make blkcg... |
303 304 305 |
* create one. blkg creation is performed recursively from blkcg_root such * that all non-root blkg's have access to the parent blkg. This function * should be called under RCU read lock and @q->queue_lock. |
86cde6b62 blkcg: reorganize... |
306 |
* |
beea9da07 blkcg: convert bl... |
307 308 |
* Returns the blkg or the closest blkg if blkg_create() fails as it walks * down from root. |
86cde6b62 blkcg: reorganize... |
309 |
*/ |
b978962ad blkcg: update blk... |
310 311 |
struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, struct request_queue *q) |
3c96cb32d blkcg: drop stuff... |
312 |
{ |
86cde6b62 blkcg: reorganize... |
313 314 315 |
struct blkcg_gq *blkg; WARN_ON_ONCE(!rcu_read_lock_held()); |
0d945c1f9 block: remove the... |
316 |
lockdep_assert_held(&q->queue_lock); |
86cde6b62 blkcg: reorganize... |
317 |
|
86cde6b62 blkcg: reorganize... |
318 319 320 |
blkg = __blkg_lookup(blkcg, q, true); if (blkg) return blkg; |
3c5478659 blkcg: make blkcg... |
321 322 |
/* * Create blkgs walking down from blkcg_root to @blkcg, so that all |
beea9da07 blkcg: convert bl... |
323 324 |
* non-root blkgs have access to their parents. Returns the closest * blkg to the intended blkg should blkg_create() fail. |
3c5478659 blkcg: make blkcg... |
325 326 327 328 |
*/ while (true) { struct blkcg *pos = blkcg; struct blkcg *parent = blkcg_parent(blkcg); |
beea9da07 blkcg: convert bl... |
329 330 331 332 333 334 335 336 337 |
struct blkcg_gq *ret_blkg = q->root_blkg; while (parent) { blkg = __blkg_lookup(parent, q, false); if (blkg) { /* remember closest blkg */ ret_blkg = blkg; break; } |
3c5478659 blkcg: make blkcg... |
338 339 340 |
pos = parent; parent = blkcg_parent(parent); } |
d708f0d50 Revert "blkcg: al... |
341 |
blkg = blkg_create(pos, q, NULL); |
beea9da07 blkcg: convert bl... |
342 343 344 |
if (IS_ERR(blkg)) return ret_blkg; if (pos == blkcg) |
3c5478659 blkcg: make blkcg... |
345 346 |
return blkg; } |
3c96cb32d blkcg: drop stuff... |
347 |
} |
31e4c28d9 blkio: Introduce ... |
348 |
|
b978962ad blkcg: update blk... |
349 350 351 352 353 354 355 356 357 358 359 360 361 362 |
/** * blkg_lookup_create - find or create a blkg * @blkcg: target block cgroup * @q: target request_queue * * This looks up or creates the blkg representing the unique pair * of the blkcg and the request_queue. */ struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, struct request_queue *q) { struct blkcg_gq *blkg = blkg_lookup(blkcg, q); if (unlikely(!blkg)) { |
3a762de55 block: save irq s... |
363 364 365 |
unsigned long flags; spin_lock_irqsave(&q->queue_lock, flags); |
b978962ad blkcg: update blk... |
366 |
blkg = __blkg_lookup_create(blkcg, q); |
3a762de55 block: save irq s... |
367 |
spin_unlock_irqrestore(&q->queue_lock, flags); |
b978962ad blkcg: update blk... |
368 369 370 371 |
} return blkg; } |
3c798398e blkcg: mass renam... |
372 |
static void blkg_destroy(struct blkcg_gq *blkg) |
03aa264ac blkcg: let blkcg ... |
373 |
{ |
3c798398e blkcg: mass renam... |
374 |
struct blkcg *blkcg = blkg->blkcg; |
77ea73388 blkcg: move io_se... |
375 |
struct blkcg_gq *parent = blkg->parent; |
6b0654620 Revert "blk-throt... |
376 |
int i; |
03aa264ac blkcg: let blkcg ... |
377 |
|
0d945c1f9 block: remove the... |
378 |
lockdep_assert_held(&blkg->q->queue_lock); |
9f13ef678 blkcg: use double... |
379 |
lockdep_assert_held(&blkcg->lock); |
03aa264ac blkcg: let blkcg ... |
380 381 |
/* Something wrong if we are trying to remove same group twice */ |
e8989fae3 blkcg: unify blkg... |
382 |
WARN_ON_ONCE(list_empty(&blkg->q_node)); |
9f13ef678 blkcg: use double... |
383 |
WARN_ON_ONCE(hlist_unhashed(&blkg->blkcg_node)); |
a637120e4 blkcg: use radix ... |
384 |
|
6b0654620 Revert "blk-throt... |
385 386 387 388 389 390 |
for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkcg_policy *pol = blkcg_policy[i]; if (blkg->pd[i] && pol->pd_offline_fn) pol->pd_offline_fn(blkg->pd[i]); } |
77ea73388 blkcg: move io_se... |
391 392 393 394 |
if (parent) { blkg_rwstat_add_aux(&parent->stat_bytes, &blkg->stat_bytes); blkg_rwstat_add_aux(&parent->stat_ios, &blkg->stat_ios); } |
f427d9096 blkcg: implement ... |
395 |
blkg->online = false; |
a637120e4 blkcg: use radix ... |
396 |
radix_tree_delete(&blkcg->blkg_tree, blkg->q->id); |
e8989fae3 blkcg: unify blkg... |
397 |
list_del_init(&blkg->q_node); |
9f13ef678 blkcg: use double... |
398 |
hlist_del_init_rcu(&blkg->blkcg_node); |
03aa264ac blkcg: let blkcg ... |
399 |
|
03aa264ac blkcg: let blkcg ... |
400 |
/* |
a637120e4 blkcg: use radix ... |
401 402 403 404 |
* Both setting lookup hint to and clearing it from @blkg are done * under queue_lock. If it's not pointing to @blkg now, it never * will. Hint assignment itself can race safely. */ |
ec6c676a0 block: Substitute... |
405 |
if (rcu_access_pointer(blkcg->blkg_hint) == blkg) |
a637120e4 blkcg: use radix ... |
406 407 408 |
rcu_assign_pointer(blkcg->blkg_hint, NULL); /* |
03aa264ac blkcg: let blkcg ... |
409 410 411 |
* Put the reference taken at the time of creation so that when all * queues are gone, group can be destroyed. */ |
7fcf2b033 blkcg: change blk... |
412 |
percpu_ref_kill(&blkg->refcnt); |
03aa264ac blkcg: let blkcg ... |
413 |
} |
9f13ef678 blkcg: use double... |
414 415 416 |
/** * blkg_destroy_all - destroy all blkgs associated with a request_queue * @q: request_queue of interest |
9f13ef678 blkcg: use double... |
417 |
* |
3c96cb32d blkcg: drop stuff... |
418 |
* Destroy all blkgs associated with @q. |
9f13ef678 blkcg: use double... |
419 |
*/ |
3c96cb32d blkcg: drop stuff... |
420 |
static void blkg_destroy_all(struct request_queue *q) |
72e06c255 blkcg: shoot down... |
421 |
{ |
3c798398e blkcg: mass renam... |
422 |
struct blkcg_gq *blkg, *n; |
72e06c255 blkcg: shoot down... |
423 |
|
0d945c1f9 block: remove the... |
424 |
spin_lock_irq(&q->queue_lock); |
9f13ef678 blkcg: use double... |
425 |
list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) { |
3c798398e blkcg: mass renam... |
426 |
struct blkcg *blkcg = blkg->blkcg; |
72e06c255 blkcg: shoot down... |
427 |
|
9f13ef678 blkcg: use double... |
428 429 430 |
spin_lock(&blkcg->lock); blkg_destroy(blkg); spin_unlock(&blkcg->lock); |
72e06c255 blkcg: shoot down... |
431 |
} |
6fe810bda block: blkg_destr... |
432 433 |
q->root_blkg = NULL; |
0d945c1f9 block: remove the... |
434 |
spin_unlock_irq(&q->queue_lock); |
72e06c255 blkcg: shoot down... |
435 |
} |
182446d08 cgroup: pass arou... |
436 437 |
static int blkcg_reset_stats(struct cgroup_subsys_state *css, struct cftype *cftype, u64 val) |
303a3acb2 blkio: Add io con... |
438 |
{ |
182446d08 cgroup: pass arou... |
439 |
struct blkcg *blkcg = css_to_blkcg(css); |
3c798398e blkcg: mass renam... |
440 |
struct blkcg_gq *blkg; |
bc0d6501a blkcg: kill blkio... |
441 |
int i; |
303a3acb2 blkio: Add io con... |
442 |
|
838f13bf4 blkcg: allow blkc... |
443 |
mutex_lock(&blkcg_pol_mutex); |
303a3acb2 blkio: Add io con... |
444 |
spin_lock_irq(&blkcg->lock); |
997a026c8 blkcg: simplify s... |
445 446 447 448 449 450 |
/* * Note that stat reset is racy - it doesn't synchronize against * stat updates. This is a debug feature which shouldn't exist * anyway. If you get hit by a race, retry. */ |
b67bfe0d4 hlist: drop the n... |
451 |
hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { |
77ea73388 blkcg: move io_se... |
452 453 |
blkg_rwstat_reset(&blkg->stat_bytes); blkg_rwstat_reset(&blkg->stat_ios); |
8bd435b30 blkcg: remove sta... |
454 |
for (i = 0; i < BLKCG_MAX_POLS; i++) { |
3c798398e blkcg: mass renam... |
455 |
struct blkcg_policy *pol = blkcg_policy[i]; |
549d3aa87 blkcg: make blkg-... |
456 |
|
a9520cd6f blkcg: make blkcg... |
457 458 |
if (blkg->pd[i] && pol->pd_reset_stats_fn) pol->pd_reset_stats_fn(blkg->pd[i]); |
bc0d6501a blkcg: kill blkio... |
459 |
} |
303a3acb2 blkio: Add io con... |
460 |
} |
f0bdc8cdd blk-cgroup: Make ... |
461 |
|
303a3acb2 blkio: Add io con... |
462 |
spin_unlock_irq(&blkcg->lock); |
bc0d6501a blkcg: kill blkio... |
463 |
mutex_unlock(&blkcg_pol_mutex); |
303a3acb2 blkio: Add io con... |
464 465 |
return 0; } |
dd165eb3b blkcg: misc prepa... |
466 |
const char *blkg_dev_name(struct blkcg_gq *blkg) |
303a3acb2 blkio: Add io con... |
467 |
{ |
d3d32e69f blkcg: restructur... |
468 |
/* some drivers (floppy) instantiate a queue w/o disk registered */ |
dc3b17cc8 block: Use pointe... |
469 470 |
if (blkg->q->backing_dev_info->dev) return dev_name(blkg->q->backing_dev_info->dev); |
d3d32e69f blkcg: restructur... |
471 |
return NULL; |
303a3acb2 blkio: Add io con... |
472 |
} |
d3d32e69f blkcg: restructur... |
473 474 475 476 477 478 479 480 481 482 483 |
/** * blkcg_print_blkgs - helper for printing per-blkg data * @sf: seq_file to print to * @blkcg: blkcg of interest * @prfill: fill function to print out a blkg * @pol: policy in question * @data: data to be passed to @prfill * @show_total: to print out sum of prfill return values or not * * This function invokes @prfill on each blkg of @blkcg if pd for the * policy specified by @pol exists. @prfill is invoked with @sf, the |
810ecfa76 blkcg: make blkcg... |
484 485 486 |
* policy data and @data and the matching queue lock held. If @show_total * is %true, the sum of the return values from @prfill is printed with * "Total" label at the end. |
d3d32e69f blkcg: restructur... |
487 488 489 490 |
* * This is to be used to construct print functions for * cftype->read_seq_string method. */ |
3c798398e blkcg: mass renam... |
491 |
void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, |
f95a04afa blkcg: embed stru... |
492 493 |
u64 (*prfill)(struct seq_file *, struct blkg_policy_data *, int), |
3c798398e blkcg: mass renam... |
494 |
const struct blkcg_policy *pol, int data, |
ec399347d blkcg: use @pol i... |
495 |
bool show_total) |
5624a4e44 blk-throttle: Mak... |
496 |
{ |
3c798398e blkcg: mass renam... |
497 |
struct blkcg_gq *blkg; |
d3d32e69f blkcg: restructur... |
498 |
u64 total = 0; |
5624a4e44 blk-throttle: Mak... |
499 |
|
810ecfa76 blkcg: make blkcg... |
500 |
rcu_read_lock(); |
ee89f8125 Merge branch 'for... |
501 |
hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) { |
0d945c1f9 block: remove the... |
502 |
spin_lock_irq(&blkg->q->queue_lock); |
a2b1693ba blkcg: implement ... |
503 |
if (blkcg_policy_enabled(blkg->q, pol)) |
f95a04afa blkcg: embed stru... |
504 |
total += prfill(sf, blkg->pd[pol->plid], data); |
0d945c1f9 block: remove the... |
505 |
spin_unlock_irq(&blkg->q->queue_lock); |
810ecfa76 blkcg: make blkcg... |
506 507 |
} rcu_read_unlock(); |
d3d32e69f blkcg: restructur... |
508 509 510 511 512 |
if (show_total) seq_printf(sf, "Total %llu ", (unsigned long long)total); } |
829fdb500 blkcg: export con... |
513 |
EXPORT_SYMBOL_GPL(blkcg_print_blkgs); |
d3d32e69f blkcg: restructur... |
514 515 516 517 |
/** * __blkg_prfill_u64 - prfill helper for a single u64 value * @sf: seq_file to print to |
f95a04afa blkcg: embed stru... |
518 |
* @pd: policy private data of interest |
d3d32e69f blkcg: restructur... |
519 520 |
* @v: value to print * |
f95a04afa blkcg: embed stru... |
521 |
* Print @v to @sf for the device assocaited with @pd. |
d3d32e69f blkcg: restructur... |
522 |
*/ |
f95a04afa blkcg: embed stru... |
523 |
u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v) |
d3d32e69f blkcg: restructur... |
524 |
{ |
f95a04afa blkcg: embed stru... |
525 |
const char *dname = blkg_dev_name(pd->blkg); |
d3d32e69f blkcg: restructur... |
526 527 528 529 530 531 532 533 |
if (!dname) return 0; seq_printf(sf, "%s %llu ", dname, (unsigned long long)v); return v; } |
829fdb500 blkcg: export con... |
534 |
EXPORT_SYMBOL_GPL(__blkg_prfill_u64); |
d3d32e69f blkcg: restructur... |
535 536 537 538 |
/** * __blkg_prfill_rwstat - prfill helper for a blkg_rwstat * @sf: seq_file to print to |
f95a04afa blkcg: embed stru... |
539 |
* @pd: policy private data of interest |
d3d32e69f blkcg: restructur... |
540 541 |
* @rwstat: rwstat to print * |
f95a04afa blkcg: embed stru... |
542 |
* Print @rwstat to @sf for the device assocaited with @pd. |
d3d32e69f blkcg: restructur... |
543 |
*/ |
f95a04afa blkcg: embed stru... |
544 |
u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, |
7af6fd911 blk-cgroup: intro... |
545 |
const struct blkg_rwstat_sample *rwstat) |
d3d32e69f blkcg: restructur... |
546 547 548 549 550 551 |
{ static const char *rwstr[] = { [BLKG_RWSTAT_READ] = "Read", [BLKG_RWSTAT_WRITE] = "Write", [BLKG_RWSTAT_SYNC] = "Sync", [BLKG_RWSTAT_ASYNC] = "Async", |
636620b66 blkcg: Track DISC... |
552 |
[BLKG_RWSTAT_DISCARD] = "Discard", |
d3d32e69f blkcg: restructur... |
553 |
}; |
f95a04afa blkcg: embed stru... |
554 |
const char *dname = blkg_dev_name(pd->blkg); |
d3d32e69f blkcg: restructur... |
555 556 557 558 559 560 561 562 563 |
u64 v; int i; if (!dname) return 0; for (i = 0; i < BLKG_RWSTAT_NR; i++) seq_printf(sf, "%s %s %llu ", dname, rwstr[i], |
7af6fd911 blk-cgroup: intro... |
564 |
rwstat->cnt[i]); |
d3d32e69f blkcg: restructur... |
565 |
|
7af6fd911 blk-cgroup: intro... |
566 567 568 569 570 |
v = rwstat->cnt[BLKG_RWSTAT_READ] + rwstat->cnt[BLKG_RWSTAT_WRITE] + rwstat->cnt[BLKG_RWSTAT_DISCARD]; seq_printf(sf, "%s Total %llu ", dname, v); |
d3d32e69f blkcg: restructur... |
571 572 |
return v; } |
b50da39f5 blkcg: export __b... |
573 |
EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat); |
d3d32e69f blkcg: restructur... |
574 |
|
5bc4afb1e blkcg: drop BLKCG... |
575 |
/** |
5bc4afb1e blkcg: drop BLKCG... |
576 577 |
* blkg_prfill_rwstat - prfill callback for blkg_rwstat * @sf: seq_file to print to |
f95a04afa blkcg: embed stru... |
578 579 |
* @pd: policy private data of interest * @off: offset to the blkg_rwstat in @pd |
5bc4afb1e blkcg: drop BLKCG... |
580 581 582 |
* * prfill callback for printing a blkg_rwstat. */ |
f95a04afa blkcg: embed stru... |
583 584 |
u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, int off) |
d3d32e69f blkcg: restructur... |
585 |
{ |
7af6fd911 blk-cgroup: intro... |
586 |
struct blkg_rwstat_sample rwstat = { }; |
d3d32e69f blkcg: restructur... |
587 |
|
5d0b6e48c blk-cgroup: pass ... |
588 |
blkg_rwstat_read((void *)pd + off, &rwstat); |
f95a04afa blkcg: embed stru... |
589 |
return __blkg_prfill_rwstat(sf, pd, &rwstat); |
d3d32e69f blkcg: restructur... |
590 |
} |
5bc4afb1e blkcg: drop BLKCG... |
591 |
EXPORT_SYMBOL_GPL(blkg_prfill_rwstat); |
d3d32e69f blkcg: restructur... |
592 |
|
77ea73388 blkcg: move io_se... |
593 594 595 |
static u64 blkg_prfill_rwstat_field(struct seq_file *sf, struct blkg_policy_data *pd, int off) { |
7af6fd911 blk-cgroup: intro... |
596 |
struct blkg_rwstat_sample rwstat = { }; |
77ea73388 blkcg: move io_se... |
597 |
|
5d0b6e48c blk-cgroup: pass ... |
598 |
blkg_rwstat_read((void *)pd->blkg + off, &rwstat); |
77ea73388 blkcg: move io_se... |
599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 |
return __blkg_prfill_rwstat(sf, pd, &rwstat); } /** * blkg_print_stat_bytes - seq_show callback for blkg->stat_bytes * @sf: seq_file to print to * @v: unused * * To be used as cftype->seq_show to print blkg->stat_bytes. * cftype->private must be set to the blkcg_policy. */ int blkg_print_stat_bytes(struct seq_file *sf, void *v) { blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat_field, (void *)seq_cft(sf)->private, offsetof(struct blkcg_gq, stat_bytes), true); return 0; } EXPORT_SYMBOL_GPL(blkg_print_stat_bytes); /** * blkg_print_stat_bytes - seq_show callback for blkg->stat_ios * @sf: seq_file to print to * @v: unused * * To be used as cftype->seq_show to print blkg->stat_ios. cftype->private * must be set to the blkcg_policy. */ int blkg_print_stat_ios(struct seq_file *sf, void *v) { blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat_field, (void *)seq_cft(sf)->private, offsetof(struct blkcg_gq, stat_ios), true); return 0; } EXPORT_SYMBOL_GPL(blkg_print_stat_ios); static u64 blkg_prfill_rwstat_field_recursive(struct seq_file *sf, struct blkg_policy_data *pd, int off) { |
7af6fd911 blk-cgroup: intro... |
640 |
struct blkg_rwstat_sample rwstat; |
5d0b6e48c blk-cgroup: pass ... |
641 642 |
blkg_rwstat_recursive_sum(pd->blkg, NULL, off, &rwstat); |
77ea73388 blkcg: move io_se... |
643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 |
return __blkg_prfill_rwstat(sf, pd, &rwstat); } /** * blkg_print_stat_bytes_recursive - recursive version of blkg_print_stat_bytes * @sf: seq_file to print to * @v: unused */ int blkg_print_stat_bytes_recursive(struct seq_file *sf, void *v) { blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat_field_recursive, (void *)seq_cft(sf)->private, offsetof(struct blkcg_gq, stat_bytes), true); return 0; } EXPORT_SYMBOL_GPL(blkg_print_stat_bytes_recursive); /** * blkg_print_stat_ios_recursive - recursive version of blkg_print_stat_ios * @sf: seq_file to print to * @v: unused */ int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v) { blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat_field_recursive, (void *)seq_cft(sf)->private, offsetof(struct blkcg_gq, stat_ios), true); return 0; } EXPORT_SYMBOL_GPL(blkg_print_stat_ios_recursive); |
3a8b31d39 blkcg: restructur... |
675 |
/** |
16b3de665 blkcg: implement ... |
676 |
* blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat |
f12c74cab blkcg: make blkg_... |
677 678 679 |
* @blkg: blkg of interest * @pol: blkcg_policy which contains the blkg_rwstat * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg |
7af6fd911 blk-cgroup: intro... |
680 |
* @sum: blkg_rwstat_sample structure containing the results |
16b3de665 blkcg: implement ... |
681 |
* |
f12c74cab blkcg: make blkg_... |
682 683 684 685 686 687 |
* Collect the blkg_rwstat specified by @blkg, @pol and @off and all its * online descendants and their aux counts. The caller must be holding the * queue lock for online tests. * * If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it * is at @off bytes into @blkg's blkg_policy_data of the policy. |
16b3de665 blkcg: implement ... |
688 |
*/ |
5d0b6e48c blk-cgroup: pass ... |
689 |
void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, |
7af6fd911 blk-cgroup: intro... |
690 |
int off, struct blkg_rwstat_sample *sum) |
16b3de665 blkcg: implement ... |
691 |
{ |
16b3de665 blkcg: implement ... |
692 |
struct blkcg_gq *pos_blkg; |
492eb21b9 cgroup: make hier... |
693 |
struct cgroup_subsys_state *pos_css; |
239eeb085 blk-cgroup: facto... |
694 |
unsigned int i; |
16b3de665 blkcg: implement ... |
695 |
|
0d945c1f9 block: remove the... |
696 |
lockdep_assert_held(&blkg->q->queue_lock); |
16b3de665 blkcg: implement ... |
697 |
|
16b3de665 blkcg: implement ... |
698 |
rcu_read_lock(); |
f12c74cab blkcg: make blkg_... |
699 |
blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { |
3a7faeada blkcg: reduce sta... |
700 |
struct blkg_rwstat *rwstat; |
16b3de665 blkcg: implement ... |
701 702 703 |
if (!pos_blkg->online) continue; |
f12c74cab blkcg: make blkg_... |
704 705 706 707 |
if (pol) rwstat = (void *)blkg_to_pd(pos_blkg, pol) + off; else rwstat = (void *)pos_blkg + off; |
16b3de665 blkcg: implement ... |
708 |
for (i = 0; i < BLKG_RWSTAT_NR; i++) |
7af6fd911 blk-cgroup: intro... |
709 |
sum->cnt[i] = blkg_rwstat_read_counter(rwstat, i); |
16b3de665 blkcg: implement ... |
710 711 |
} rcu_read_unlock(); |
16b3de665 blkcg: implement ... |
712 713 |
} EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum); |
457e490f2 blkcg: allocate s... |
714 715 716 717 718 719 |
/* Performs queue bypass and policy enabled checks then looks up blkg. */ static struct blkcg_gq *blkg_lookup_check(struct blkcg *blkcg, const struct blkcg_policy *pol, struct request_queue *q) { WARN_ON_ONCE(!rcu_read_lock_held()); |
0d945c1f9 block: remove the... |
720 |
lockdep_assert_held(&q->queue_lock); |
457e490f2 blkcg: allocate s... |
721 722 723 |
if (!blkcg_policy_enabled(q, pol)) return ERR_PTR(-EOPNOTSUPP); |
457e490f2 blkcg: allocate s... |
724 725 |
return __blkg_lookup(blkcg, q, true /* update_hint */); } |
16b3de665 blkcg: implement ... |
726 |
/** |
3a8b31d39 blkcg: restructur... |
727 |
* blkg_conf_prep - parse and prepare for per-blkg config update |
015d254cb blkcg: separate b... |
728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 |
* @inputp: input string pointer * * Parse the device node prefix part, MAJ:MIN, of per-blkg config update * from @input and get and return the matching gendisk. *@inputp is * updated to point past the device node prefix. Returns an ERR_PTR() * value on error. * * Use this function iff blkg_conf_prep() can't be used for some reason. */ struct gendisk *blkcg_conf_get_disk(char **inputp) { char *input = *inputp; unsigned int major, minor; struct gendisk *disk; int key_len, part; if (sscanf(input, "%u:%u%n", &major, &minor, &key_len) != 2) return ERR_PTR(-EINVAL); input += key_len; if (!isspace(*input)) return ERR_PTR(-EINVAL); input = skip_spaces(input); disk = get_gendisk(MKDEV(major, minor), &part); if (!disk) return ERR_PTR(-ENODEV); if (part) { put_disk_and_module(disk); return ERR_PTR(-ENODEV); } *inputp = input; return disk; } /** * blkg_conf_prep - parse and prepare for per-blkg config update |
3a8b31d39 blkcg: restructur... |
766 |
* @blkcg: target block cgroup |
da8b06626 blkcg: make blkg_... |
767 |
* @pol: target policy |
3a8b31d39 blkcg: restructur... |
768 769 770 771 |
* @input: input string * @ctx: blkg_conf_ctx to be filled * * Parse per-blkg config update from @input and initialize @ctx with the |
36aa9e5f5 blkcg: move body ... |
772 773 774 |
* result. @ctx->blkg points to the blkg to be updated and @ctx->body the * part of @input following MAJ:MIN. This function returns with RCU read * lock and queue lock held and must be paired with blkg_conf_finish(). |
3a8b31d39 blkcg: restructur... |
775 |
*/ |
3c798398e blkcg: mass renam... |
776 |
int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, |
36aa9e5f5 blkcg: move body ... |
777 |
char *input, struct blkg_conf_ctx *ctx) |
0d945c1f9 block: remove the... |
778 |
__acquires(rcu) __acquires(&disk->queue->queue_lock) |
34d0f179d io-controller: Ad... |
779 |
{ |
3a8b31d39 blkcg: restructur... |
780 |
struct gendisk *disk; |
457e490f2 blkcg: allocate s... |
781 |
struct request_queue *q; |
3c798398e blkcg: mass renam... |
782 |
struct blkcg_gq *blkg; |
015d254cb blkcg: separate b... |
783 |
int ret; |
36aa9e5f5 blkcg: move body ... |
784 |
|
015d254cb blkcg: separate b... |
785 786 787 |
disk = blkcg_conf_get_disk(&input); if (IS_ERR(disk)) return PTR_ERR(disk); |
e56da7e28 blkcg: don't allo... |
788 |
|
457e490f2 blkcg: allocate s... |
789 |
q = disk->queue; |
da8b06626 blkcg: make blkg_... |
790 |
|
457e490f2 blkcg: allocate s... |
791 |
rcu_read_lock(); |
0d945c1f9 block: remove the... |
792 |
spin_lock_irq(&q->queue_lock); |
e56da7e28 blkcg: don't allo... |
793 |
|
457e490f2 blkcg: allocate s... |
794 |
blkg = blkg_lookup_check(blkcg, pol, q); |
4bfd482e7 blkcg: kill blkio... |
795 796 |
if (IS_ERR(blkg)) { ret = PTR_ERR(blkg); |
457e490f2 blkcg: allocate s... |
797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 |
goto fail_unlock; } if (blkg) goto success; /* * Create blkgs walking down from blkcg_root to @blkcg, so that all * non-root blkgs have access to their parents. */ while (true) { struct blkcg *pos = blkcg; struct blkcg *parent; struct blkcg_gq *new_blkg; parent = blkcg_parent(blkcg); while (parent && !__blkg_lookup(parent, q, false)) { pos = parent; parent = blkcg_parent(parent); } /* Drop locks to do new blkg allocation with GFP_KERNEL. */ |
0d945c1f9 block: remove the... |
819 |
spin_unlock_irq(&q->queue_lock); |
3a8b31d39 blkcg: restructur... |
820 |
rcu_read_unlock(); |
457e490f2 blkcg: allocate s... |
821 822 823 824 825 |
new_blkg = blkg_alloc(pos, q, GFP_KERNEL); if (unlikely(!new_blkg)) { ret = -ENOMEM; goto fail; |
7702e8f45 blk-cgroup: cgrou... |
826 |
} |
3a8b31d39 blkcg: restructur... |
827 |
|
457e490f2 blkcg: allocate s... |
828 |
rcu_read_lock(); |
0d945c1f9 block: remove the... |
829 |
spin_lock_irq(&q->queue_lock); |
457e490f2 blkcg: allocate s... |
830 831 832 833 834 835 836 837 838 839 840 |
blkg = blkg_lookup_check(pos, pol, q); if (IS_ERR(blkg)) { ret = PTR_ERR(blkg); goto fail_unlock; } if (blkg) { blkg_free(new_blkg); } else { blkg = blkg_create(pos, q, new_blkg); |
98d669b49 block: Drop unlik... |
841 |
if (IS_ERR(blkg)) { |
457e490f2 blkcg: allocate s... |
842 843 844 845 846 847 848 849 850 |
ret = PTR_ERR(blkg); goto fail_unlock; } } if (pos == blkcg) goto success; } success: |
3a8b31d39 blkcg: restructur... |
851 852 |
ctx->disk = disk; ctx->blkg = blkg; |
015d254cb blkcg: separate b... |
853 |
ctx->body = input; |
726fa6945 blkcg: simplify b... |
854 |
return 0; |
457e490f2 blkcg: allocate s... |
855 856 |
fail_unlock: |
0d945c1f9 block: remove the... |
857 |
spin_unlock_irq(&q->queue_lock); |
457e490f2 blkcg: allocate s... |
858 859 |
rcu_read_unlock(); fail: |
9df6c2991 genhd: Add helper... |
860 |
put_disk_and_module(disk); |
457e490f2 blkcg: allocate s... |
861 862 863 864 865 866 867 868 869 870 871 |
/* * If queue was bypassing, we should retry. Do so after a * short msleep(). It isn't strictly necessary but queue * can be bypassing for some time and it's always nice to * avoid busy looping. */ if (ret == -EBUSY) { msleep(10); ret = restart_syscall(); } return ret; |
34d0f179d io-controller: Ad... |
872 |
} |
89f3b6d62 bfq: Fix bfq link... |
873 |
EXPORT_SYMBOL_GPL(blkg_conf_prep); |
34d0f179d io-controller: Ad... |
874 |
|
3a8b31d39 blkcg: restructur... |
875 876 877 878 879 880 881 |
/** * blkg_conf_finish - finish up per-blkg config update * @ctx: blkg_conf_ctx intiailized by blkg_conf_prep() * * Finish up after per-blkg config update. This function must be paired * with blkg_conf_prep(). */ |
829fdb500 blkcg: export con... |
882 |
void blkg_conf_finish(struct blkg_conf_ctx *ctx) |
0d945c1f9 block: remove the... |
883 |
__releases(&ctx->disk->queue->queue_lock) __releases(rcu) |
34d0f179d io-controller: Ad... |
884 |
{ |
0d945c1f9 block: remove the... |
885 |
spin_unlock_irq(&ctx->disk->queue->queue_lock); |
3a8b31d39 blkcg: restructur... |
886 |
rcu_read_unlock(); |
9df6c2991 genhd: Add helper... |
887 |
put_disk_and_module(ctx->disk); |
34d0f179d io-controller: Ad... |
888 |
} |
89f3b6d62 bfq: Fix bfq link... |
889 |
EXPORT_SYMBOL_GPL(blkg_conf_finish); |
34d0f179d io-controller: Ad... |
890 |
|
2ee867dcf blkcg: implement ... |
891 892 893 894 895 896 897 898 899 |
static int blkcg_print_stat(struct seq_file *sf, void *v) { struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); struct blkcg_gq *blkg; rcu_read_lock(); hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) { const char *dname; |
903d23f0a blk-cgroup: allow... |
900 |
char *buf; |
7af6fd911 blk-cgroup: intro... |
901 |
struct blkg_rwstat_sample rwstat; |
636620b66 blkcg: Track DISC... |
902 |
u64 rbytes, wbytes, rios, wios, dbytes, dios; |
903d23f0a blk-cgroup: allow... |
903 904 905 |
size_t size = seq_get_buf(sf, &buf), off = 0; int i; bool has_stats = false; |
2ee867dcf blkcg: implement ... |
906 |
|
b0814361a blkcg: make blkcg... |
907 908 909 910 |
spin_lock_irq(&blkg->q->queue_lock); if (!blkg->online) goto skip; |
2ee867dcf blkcg: implement ... |
911 912 |
dname = blkg_dev_name(blkg); if (!dname) |
b0814361a blkcg: make blkcg... |
913 |
goto skip; |
2ee867dcf blkcg: implement ... |
914 |
|
903d23f0a blk-cgroup: allow... |
915 916 917 918 919 920 921 |
/* * Hooray string manipulation, count is the size written NOT * INCLUDING THE \0, so size is now count+1 less than what we * had before, but we want to start writing the next bit from * the \0 so we only add count to buf. */ off += scnprintf(buf+off, size-off, "%s ", dname); |
5d0b6e48c blk-cgroup: pass ... |
922 923 |
blkg_rwstat_recursive_sum(blkg, NULL, offsetof(struct blkcg_gq, stat_bytes), &rwstat); |
7af6fd911 blk-cgroup: intro... |
924 925 926 |
rbytes = rwstat.cnt[BLKG_RWSTAT_READ]; wbytes = rwstat.cnt[BLKG_RWSTAT_WRITE]; dbytes = rwstat.cnt[BLKG_RWSTAT_DISCARD]; |
2ee867dcf blkcg: implement ... |
927 |
|
5d0b6e48c blk-cgroup: pass ... |
928 929 |
blkg_rwstat_recursive_sum(blkg, NULL, offsetof(struct blkcg_gq, stat_ios), &rwstat); |
7af6fd911 blk-cgroup: intro... |
930 931 932 |
rios = rwstat.cnt[BLKG_RWSTAT_READ]; wios = rwstat.cnt[BLKG_RWSTAT_WRITE]; dios = rwstat.cnt[BLKG_RWSTAT_DISCARD]; |
2ee867dcf blkcg: implement ... |
933 |
|
903d23f0a blk-cgroup: allow... |
934 935 936 |
if (rbytes || wbytes || rios || wios) { has_stats = true; off += scnprintf(buf+off, size-off, |
636620b66 blkcg: Track DISC... |
937 938 939 |
"rbytes=%llu wbytes=%llu rios=%llu wios=%llu dbytes=%llu dios=%llu", rbytes, wbytes, rios, wios, dbytes, dios); |
903d23f0a blk-cgroup: allow... |
940 |
} |
07b0fdecb blkcg: allow blkc... |
941 |
if (blkcg_debug_stats && atomic_read(&blkg->use_delay)) { |
d09d8df3a blkcg: add generi... |
942 943 944 945 946 947 |
has_stats = true; off += scnprintf(buf+off, size-off, " use_delay=%d delay_nsec=%llu", atomic_read(&blkg->use_delay), (unsigned long long)atomic64_read(&blkg->delay_nsec)); } |
903d23f0a blk-cgroup: allow... |
948 949 950 951 952 953 954 955 956 957 958 959 |
for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkcg_policy *pol = blkcg_policy[i]; size_t written; if (!blkg->pd[i] || !pol->pd_stat_fn) continue; written = pol->pd_stat_fn(blkg->pd[i], buf+off, size-off); if (written) has_stats = true; off += written; } |
07b0fdecb blkcg: allow blkc... |
960 |
|
903d23f0a blk-cgroup: allow... |
961 |
if (has_stats) { |
f539da82f blkcg: update blk... |
962 963 964 965 966 967 968 |
if (off < size - 1) { off += scnprintf(buf+off, size-off, " "); seq_commit(sf, off); } else { seq_commit(sf, -1); } |
903d23f0a blk-cgroup: allow... |
969 |
} |
b0814361a blkcg: make blkcg... |
970 971 |
skip: spin_unlock_irq(&blkg->q->queue_lock); |
2ee867dcf blkcg: implement ... |
972 973 974 975 976 |
} rcu_read_unlock(); return 0; } |
e1f3b9412 block/blk-cgroup.... |
977 |
static struct cftype blkcg_files[] = { |
2ee867dcf blkcg: implement ... |
978 979 |
{ .name = "stat", |
ca0752c5e blkcg: don't crea... |
980 |
.flags = CFTYPE_NOT_ON_ROOT, |
2ee867dcf blkcg: implement ... |
981 982 983 984 |
.seq_show = blkcg_print_stat, }, { } /* terminate */ }; |
e1f3b9412 block/blk-cgroup.... |
985 |
static struct cftype blkcg_legacy_files[] = { |
31e4c28d9 blkio: Introduce ... |
986 |
{ |
84c124da9 blkio: Changes to... |
987 |
.name = "reset_stats", |
3c798398e blkcg: mass renam... |
988 |
.write_u64 = blkcg_reset_stats, |
220841906 blkio: Export dis... |
989 |
}, |
4baf6e332 cgroup: convert a... |
990 |
{ } /* terminate */ |
31e4c28d9 blkio: Introduce ... |
991 |
}; |
59b57717f blkcg: delay blkg... |
992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 |
/* * blkcg destruction is a three-stage process. * * 1. Destruction starts. The blkcg_css_offline() callback is invoked * which offlines writeback. Here we tie the next stage of blkg destruction * to the completion of writeback associated with the blkcg. This lets us * avoid punting potentially large amounts of outstanding writeback to root * while maintaining any ongoing policies. The next stage is triggered when * the nr_cgwbs count goes to zero. * * 2. When the nr_cgwbs count goes to zero, blkcg_destroy_blkgs() is called * and handles the destruction of blkgs. Here the css reference held by * the blkg is put back eventually allowing blkcg_css_free() to be called. * This work may occur in cgwb_release_workfn() on the cgwb_release * workqueue. Any submitted ios that fail to get the blkg ref will be * punted to the root_blkg. * * 3. Once the blkcg ref count goes to zero, blkcg_css_free() is called. * This finally frees the blkcg. */ |
9f13ef678 blkcg: use double... |
1012 |
/** |
92fb97487 cgroup: rename ->... |
1013 |
* blkcg_css_offline - cgroup css_offline callback |
eb95419b0 cgroup: pass arou... |
1014 |
* @css: css of interest |
9f13ef678 blkcg: use double... |
1015 |
* |
59b57717f blkcg: delay blkg... |
1016 1017 1018 |
* This function is called when @css is about to go away. Here the cgwbs are * offlined first and only once writeback associated with the blkcg has * finished do we start step 2 (see above). |
9f13ef678 blkcg: use double... |
1019 |
*/ |
eb95419b0 cgroup: pass arou... |
1020 |
static void blkcg_css_offline(struct cgroup_subsys_state *css) |
31e4c28d9 blkio: Introduce ... |
1021 |
{ |
eb95419b0 cgroup: pass arou... |
1022 |
struct blkcg *blkcg = css_to_blkcg(css); |
b1c357696 blkio: Take care ... |
1023 |
|
59b57717f blkcg: delay blkg... |
1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 |
/* this prevents anyone from attaching or migrating to this blkcg */ wb_blkcg_offline(blkcg); /* put the base cgwb reference allowing step 2 to be triggered */ blkcg_cgwb_put(blkcg); } /** * blkcg_destroy_blkgs - responsible for shooting down blkgs * @blkcg: blkcg of interest * * blkgs should be removed while holding both q and blkcg locks. As blkcg lock * is nested inside q lock, this function performs reverse double lock dancing. * Destroying the blkgs releases the reference held on the blkcg's css allowing * blkcg_css_free to eventually be called. * * This is the blkcg counterpart of ioc_release_fn(). */ void blkcg_destroy_blkgs(struct blkcg *blkcg) { |
9f13ef678 blkcg: use double... |
1044 |
spin_lock_irq(&blkcg->lock); |
7ee9c5620 blkcg: let blkio_... |
1045 |
|
4c6994806 blk-throttle: fix... |
1046 1047 |
while (!hlist_empty(&blkcg->blkg_list)) { struct blkcg_gq *blkg = hlist_entry(blkcg->blkg_list.first, |
6b0654620 Revert "blk-throt... |
1048 |
struct blkcg_gq, blkcg_node); |
4c6994806 blk-throttle: fix... |
1049 |
struct request_queue *q = blkg->q; |
0d945c1f9 block: remove the... |
1050 |
if (spin_trylock(&q->queue_lock)) { |
4c6994806 blk-throttle: fix... |
1051 |
blkg_destroy(blkg); |
0d945c1f9 block: remove the... |
1052 |
spin_unlock(&q->queue_lock); |
4c6994806 blk-throttle: fix... |
1053 1054 1055 1056 1057 1058 |
} else { spin_unlock_irq(&blkcg->lock); cpu_relax(); spin_lock_irq(&blkcg->lock); } } |
6b0654620 Revert "blk-throt... |
1059 |
|
4c6994806 blk-throttle: fix... |
1060 1061 |
spin_unlock_irq(&blkcg->lock); } |
eb95419b0 cgroup: pass arou... |
1062 |
static void blkcg_css_free(struct cgroup_subsys_state *css) |
7ee9c5620 blkcg: let blkio_... |
1063 |
{ |
eb95419b0 cgroup: pass arou... |
1064 |
struct blkcg *blkcg = css_to_blkcg(css); |
bc915e61c blkcg: remove unn... |
1065 |
int i; |
7ee9c5620 blkcg: let blkio_... |
1066 |
|
7876f930d blkcg: implement ... |
1067 |
mutex_lock(&blkcg_pol_mutex); |
e4a9bde95 blkcg: replace bl... |
1068 |
|
7876f930d blkcg: implement ... |
1069 |
list_del(&blkcg->all_blkcgs_node); |
7876f930d blkcg: implement ... |
1070 |
|
bc915e61c blkcg: remove unn... |
1071 |
for (i = 0; i < BLKCG_MAX_POLS; i++) |
e4a9bde95 blkcg: replace bl... |
1072 1073 1074 1075 |
if (blkcg->cpd[i]) blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]); mutex_unlock(&blkcg_pol_mutex); |
bc915e61c blkcg: remove unn... |
1076 |
kfree(blkcg); |
31e4c28d9 blkio: Introduce ... |
1077 |
} |
eb95419b0 cgroup: pass arou... |
1078 1079 |
static struct cgroup_subsys_state * blkcg_css_alloc(struct cgroup_subsys_state *parent_css) |
31e4c28d9 blkio: Introduce ... |
1080 |
{ |
3c798398e blkcg: mass renam... |
1081 |
struct blkcg *blkcg; |
e48453c38 block, cgroup: im... |
1082 1083 |
struct cgroup_subsys_state *ret; int i; |
31e4c28d9 blkio: Introduce ... |
1084 |
|
7876f930d blkcg: implement ... |
1085 |
mutex_lock(&blkcg_pol_mutex); |
eb95419b0 cgroup: pass arou... |
1086 |
if (!parent_css) { |
3c798398e blkcg: mass renam... |
1087 |
blkcg = &blkcg_root; |
bc915e61c blkcg: remove unn... |
1088 1089 1090 1091 |
} else { blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); if (!blkcg) { ret = ERR_PTR(-ENOMEM); |
4c18c9e96 blkcg: avoid free... |
1092 |
goto unlock; |
bc915e61c blkcg: remove unn... |
1093 |
} |
e48453c38 block, cgroup: im... |
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 |
} for (i = 0; i < BLKCG_MAX_POLS ; i++) { struct blkcg_policy *pol = blkcg_policy[i]; struct blkcg_policy_data *cpd; /* * If the policy hasn't been attached yet, wait for it * to be attached before doing anything else. Otherwise, * check if the policy requires any specific per-cgroup * data: if it does, allocate and initialize it. */ |
e4a9bde95 blkcg: replace bl... |
1106 |
if (!pol || !pol->cpd_alloc_fn) |
e48453c38 block, cgroup: im... |
1107 |
continue; |
e4a9bde95 blkcg: replace bl... |
1108 |
cpd = pol->cpd_alloc_fn(GFP_KERNEL); |
e48453c38 block, cgroup: im... |
1109 1110 1111 1112 |
if (!cpd) { ret = ERR_PTR(-ENOMEM); goto free_pd_blkcg; } |
814376483 blkcg: minor upda... |
1113 1114 |
blkcg->cpd[i] = cpd; cpd->blkcg = blkcg; |
e48453c38 block, cgroup: im... |
1115 |
cpd->plid = i; |
e4a9bde95 blkcg: replace bl... |
1116 1117 |
if (pol->cpd_init_fn) pol->cpd_init_fn(cpd); |
e48453c38 block, cgroup: im... |
1118 |
} |
31e4c28d9 blkio: Introduce ... |
1119 |
|
31e4c28d9 blkio: Introduce ... |
1120 |
spin_lock_init(&blkcg->lock); |
e00f4f4d0 block,blkcg: use ... |
1121 |
INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT | __GFP_NOWARN); |
31e4c28d9 blkio: Introduce ... |
1122 |
INIT_HLIST_HEAD(&blkcg->blkg_list); |
52ebea749 writeback: make b... |
1123 1124 |
#ifdef CONFIG_CGROUP_WRITEBACK INIT_LIST_HEAD(&blkcg->cgwb_list); |
59b57717f blkcg: delay blkg... |
1125 |
refcount_set(&blkcg->cgwb_refcnt, 1); |
52ebea749 writeback: make b... |
1126 |
#endif |
7876f930d blkcg: implement ... |
1127 1128 1129 |
list_add_tail(&blkcg->all_blkcgs_node, &all_blkcgs); mutex_unlock(&blkcg_pol_mutex); |
31e4c28d9 blkio: Introduce ... |
1130 |
return &blkcg->css; |
e48453c38 block, cgroup: im... |
1131 1132 1133 |
free_pd_blkcg: for (i--; i >= 0; i--) |
e4a9bde95 blkcg: replace bl... |
1134 1135 |
if (blkcg->cpd[i]) blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]); |
4c18c9e96 blkcg: avoid free... |
1136 1137 1138 1139 |
if (blkcg != &blkcg_root) kfree(blkcg); unlock: |
7876f930d blkcg: implement ... |
1140 |
mutex_unlock(&blkcg_pol_mutex); |
e48453c38 block, cgroup: im... |
1141 |
return ret; |
31e4c28d9 blkio: Introduce ... |
1142 |
} |
5efd61135 blkcg: add blkcg_... |
1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 |
/** * blkcg_init_queue - initialize blkcg part of request queue * @q: request_queue to initialize * * Called from blk_alloc_queue_node(). Responsible for initializing blkcg * part of new request_queue @q. * * RETURNS: * 0 on success, -errno on failure. */ int blkcg_init_queue(struct request_queue *q) { |
d708f0d50 Revert "blkcg: al... |
1155 1156 |
struct blkcg_gq *new_blkg, *blkg; bool preloaded; |
ec13b1d6f blkcg: always cre... |
1157 |
int ret; |
d708f0d50 Revert "blkcg: al... |
1158 1159 1160 1161 1162 |
new_blkg = blkg_alloc(&blkcg_root, q, GFP_KERNEL); if (!new_blkg) return -ENOMEM; preloaded = !radix_tree_preload(GFP_KERNEL); |
bea548831 blkcg: small fix ... |
1163 |
/* Make sure the root blkg exists. */ |
ec13b1d6f blkcg: always cre... |
1164 |
rcu_read_lock(); |
0d945c1f9 block: remove the... |
1165 |
spin_lock_irq(&q->queue_lock); |
d708f0d50 Revert "blkcg: al... |
1166 |
blkg = blkg_create(&blkcg_root, q, new_blkg); |
901932a3f blkcg: init root ... |
1167 1168 1169 |
if (IS_ERR(blkg)) goto err_unlock; q->root_blkg = blkg; |
0d945c1f9 block: remove the... |
1170 |
spin_unlock_irq(&q->queue_lock); |
ec13b1d6f blkcg: always cre... |
1171 |
rcu_read_unlock(); |
d708f0d50 Revert "blkcg: al... |
1172 1173 |
if (preloaded) radix_tree_preload_end(); |
05c608f63 blkcg: fix memlea... |
1174 |
ret = blk_throtl_init(q); |
04be60b5e blk-cgroup: conso... |
1175 1176 |
if (ret) goto err_destroy_all; |
d70675121 block: introduce ... |
1177 |
|
05c608f63 blkcg: fix memlea... |
1178 1179 1180 |
ret = blk_iolatency_init(q); if (ret) { blk_throtl_exit(q); |
04be60b5e blk-cgroup: conso... |
1181 |
goto err_destroy_all; |
05c608f63 blkcg: fix memlea... |
1182 |
} |
04be60b5e blk-cgroup: conso... |
1183 |
return 0; |
901932a3f blkcg: init root ... |
1184 |
|
04be60b5e blk-cgroup: conso... |
1185 |
err_destroy_all: |
04be60b5e blk-cgroup: conso... |
1186 |
blkg_destroy_all(q); |
04be60b5e blk-cgroup: conso... |
1187 |
return ret; |
901932a3f blkcg: init root ... |
1188 |
err_unlock: |
0d945c1f9 block: remove the... |
1189 |
spin_unlock_irq(&q->queue_lock); |
901932a3f blkcg: init root ... |
1190 1191 1192 1193 |
rcu_read_unlock(); if (preloaded) radix_tree_preload_end(); return PTR_ERR(blkg); |
5efd61135 blkcg: add blkcg_... |
1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 |
} /** * blkcg_drain_queue - drain blkcg part of request_queue * @q: request_queue to drain * * Called from blk_drain_queue(). Responsible for draining blkcg part. */ void blkcg_drain_queue(struct request_queue *q) { |
0d945c1f9 block: remove the... |
1204 |
lockdep_assert_held(&q->queue_lock); |
5efd61135 blkcg: add blkcg_... |
1205 |
|
0b462c89e blkcg: don't call... |
1206 1207 1208 1209 1210 1211 |
/* * @q could be exiting and already have destroyed all blkgs as * indicated by NULL root_blkg. If so, don't confuse policies. */ if (!q->root_blkg) return; |
5efd61135 blkcg: add blkcg_... |
1212 1213 1214 1215 1216 1217 1218 |
blk_throtl_drain(q); } /** * blkcg_exit_queue - exit and release blkcg part of request_queue * @q: request_queue being released * |
7585d5082 blk-cgroup: Fix d... |
1219 |
* Called from blk_exit_queue(). Responsible for exiting blkcg part. |
5efd61135 blkcg: add blkcg_... |
1220 1221 1222 |
*/ void blkcg_exit_queue(struct request_queue *q) { |
3c96cb32d blkcg: drop stuff... |
1223 |
blkg_destroy_all(q); |
5efd61135 blkcg: add blkcg_... |
1224 1225 |
blk_throtl_exit(q); } |
31e4c28d9 blkio: Introduce ... |
1226 1227 1228 1229 1230 1231 |
/* * We cannot support shared io contexts, as we have no mean to support * two tasks with the same ioc in two different groups without major rework * of the main cic data structures. For now we allow a task to change * its cgroup only if it's the only owner of its ioc. */ |
1f7dd3e5a cgroup: fix handl... |
1232 |
static int blkcg_can_attach(struct cgroup_taskset *tset) |
31e4c28d9 blkio: Introduce ... |
1233 |
{ |
bb9d97b6d cgroup: don't use... |
1234 |
struct task_struct *task; |
1f7dd3e5a cgroup: fix handl... |
1235 |
struct cgroup_subsys_state *dst_css; |
31e4c28d9 blkio: Introduce ... |
1236 1237 1238 1239 |
struct io_context *ioc; int ret = 0; /* task_lock() is needed to avoid races with exit_io_context() */ |
1f7dd3e5a cgroup: fix handl... |
1240 |
cgroup_taskset_for_each(task, dst_css, tset) { |
bb9d97b6d cgroup: don't use... |
1241 1242 1243 1244 1245 1246 1247 1248 |
task_lock(task); ioc = task->io_context; if (ioc && atomic_read(&ioc->nr_tasks) > 1) ret = -EINVAL; task_unlock(task); if (ret) break; } |
31e4c28d9 blkio: Introduce ... |
1249 1250 |
return ret; } |
69d7fde59 blkcg: use CGROUP... |
1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 |
static void blkcg_bind(struct cgroup_subsys_state *root_css) { int i; mutex_lock(&blkcg_pol_mutex); for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkcg_policy *pol = blkcg_policy[i]; struct blkcg *blkcg; if (!pol || !pol->cpd_bind_fn) continue; list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) if (blkcg->cpd[pol->plid]) pol->cpd_bind_fn(blkcg->cpd[pol->plid]); } mutex_unlock(&blkcg_pol_mutex); } |
d09d8df3a blkcg: add generi... |
1270 1271 1272 1273 1274 1275 |
static void blkcg_exit(struct task_struct *tsk) { if (tsk->throttle_queue) blk_put_queue(tsk->throttle_queue); tsk->throttle_queue = NULL; } |
c165b3e3c blkcg: rename sub... |
1276 |
struct cgroup_subsys io_cgrp_subsys = { |
92fb97487 cgroup: rename ->... |
1277 1278 1279 |
.css_alloc = blkcg_css_alloc, .css_offline = blkcg_css_offline, .css_free = blkcg_css_free, |
3c798398e blkcg: mass renam... |
1280 |
.can_attach = blkcg_can_attach, |
69d7fde59 blkcg: use CGROUP... |
1281 |
.bind = blkcg_bind, |
2ee867dcf blkcg: implement ... |
1282 |
.dfl_cftypes = blkcg_files, |
880f50e22 blkcg: mark exist... |
1283 |
.legacy_cftypes = blkcg_legacy_files, |
c165b3e3c blkcg: rename sub... |
1284 |
.legacy_name = "blkio", |
d09d8df3a blkcg: add generi... |
1285 |
.exit = blkcg_exit, |
1ced953b1 blkcg, memcg: mak... |
1286 1287 1288 1289 1290 1291 1292 1293 |
#ifdef CONFIG_MEMCG /* * This ensures that, if available, memcg is automatically enabled * together on the default hierarchy so that the owner cgroup can * be retrieved from writeback pages. */ .depends_on = 1 << memory_cgrp_id, #endif |
676f7c8f8 cgroup: relocate ... |
1294 |
}; |
c165b3e3c blkcg: rename sub... |
1295 |
EXPORT_SYMBOL_GPL(io_cgrp_subsys); |
676f7c8f8 cgroup: relocate ... |
1296 |
|
8bd435b30 blkcg: remove sta... |
1297 |
/** |
a2b1693ba blkcg: implement ... |
1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 |
* blkcg_activate_policy - activate a blkcg policy on a request_queue * @q: request_queue of interest * @pol: blkcg policy to activate * * Activate @pol on @q. Requires %GFP_KERNEL context. @q goes through * bypass mode to populate its blkgs with policy_data for @pol. * * Activation happens with @q bypassed, so nobody would be accessing blkgs * from IO path. Update of each blkg is protected by both queue and blkcg * locks so that holding either lock and testing blkcg_policy_enabled() is * always enough for dereferencing policy data. * * The caller is responsible for synchronizing [de]activations and policy * [un]registerations. Returns 0 on success, -errno on failure. */ int blkcg_activate_policy(struct request_queue *q, |
3c798398e blkcg: mass renam... |
1314 |
const struct blkcg_policy *pol) |
a2b1693ba blkcg: implement ... |
1315 |
{ |
4c55f4f9a blkcg: restructur... |
1316 |
struct blkg_policy_data *pd_prealloc = NULL; |
9d179b865 blkcg: Fix multip... |
1317 |
struct blkcg_gq *blkg, *pinned_blkg = NULL; |
4c55f4f9a blkcg: restructur... |
1318 |
int ret; |
a2b1693ba blkcg: implement ... |
1319 1320 1321 |
if (blkcg_policy_enabled(q, pol)) return 0; |
344e9ffcb block: add queue_... |
1322 |
if (queue_is_mq(q)) |
bd166ef18 blk-mq-sched: add... |
1323 |
blk_mq_freeze_queue(q); |
9d179b865 blkcg: Fix multip... |
1324 |
retry: |
0d945c1f9 block: remove the... |
1325 |
spin_lock_irq(&q->queue_lock); |
a2b1693ba blkcg: implement ... |
1326 |
|
9d179b865 blkcg: Fix multip... |
1327 |
/* blkg_list is pushed at the head, reverse walk to allocate parents first */ |
71c814077 blkcg: blkcg_acti... |
1328 |
list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) { |
4c55f4f9a blkcg: restructur... |
1329 1330 1331 1332 |
struct blkg_policy_data *pd; if (blkg->pd[pol->plid]) continue; |
a2b1693ba blkcg: implement ... |
1333 |
|
9d179b865 blkcg: Fix multip... |
1334 1335 1336 1337 1338 1339 1340 1341 |
/* If prealloc matches, use it; otherwise try GFP_NOWAIT */ if (blkg == pinned_blkg) { pd = pd_prealloc; pd_prealloc = NULL; } else { pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q, blkg->blkcg); } |
4c55f4f9a blkcg: restructur... |
1342 |
if (!pd) { |
9d179b865 blkcg: Fix multip... |
1343 1344 1345 1346 1347 1348 1349 1350 |
/* * GFP_NOWAIT failed. Free the existing one and * prealloc for @blkg w/ GFP_KERNEL. */ if (pinned_blkg) blkg_put(pinned_blkg); blkg_get(blkg); pinned_blkg = blkg; |
0d945c1f9 block: remove the... |
1351 |
spin_unlock_irq(&q->queue_lock); |
9d179b865 blkcg: Fix multip... |
1352 1353 1354 1355 1356 1357 1358 1359 1360 |
if (pd_prealloc) pol->pd_free_fn(pd_prealloc); pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q, blkg->blkcg); if (pd_prealloc) goto retry; else goto enomem; |
4c55f4f9a blkcg: restructur... |
1361 |
} |
a2b1693ba blkcg: implement ... |
1362 1363 1364 |
blkg->pd[pol->plid] = pd; pd->blkg = blkg; |
b276a876a blkcg: add blkg_p... |
1365 |
pd->plid = pol->plid; |
a2b1693ba blkcg: implement ... |
1366 |
} |
9d179b865 blkcg: Fix multip... |
1367 1368 1369 1370 |
/* all allocated, init in the same order */ if (pol->pd_init_fn) list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) pol->pd_init_fn(blkg->pd[pol->plid]); |
a2b1693ba blkcg: implement ... |
1371 1372 |
__set_bit(pol->plid, q->blkcg_pols); ret = 0; |
4c55f4f9a blkcg: restructur... |
1373 |
|
0d945c1f9 block: remove the... |
1374 |
spin_unlock_irq(&q->queue_lock); |
9d179b865 blkcg: Fix multip... |
1375 |
out: |
344e9ffcb block: add queue_... |
1376 |
if (queue_is_mq(q)) |
bd166ef18 blk-mq-sched: add... |
1377 |
blk_mq_unfreeze_queue(q); |
9d179b865 blkcg: Fix multip... |
1378 1379 |
if (pinned_blkg) blkg_put(pinned_blkg); |
001bea73e blkcg: replace bl... |
1380 1381 |
if (pd_prealloc) pol->pd_free_fn(pd_prealloc); |
a2b1693ba blkcg: implement ... |
1382 |
return ret; |
9d179b865 blkcg: Fix multip... |
1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 |
enomem: /* alloc failed, nothing's initialized yet, free everything */ spin_lock_irq(&q->queue_lock); list_for_each_entry(blkg, &q->blkg_list, q_node) { if (blkg->pd[pol->plid]) { pol->pd_free_fn(blkg->pd[pol->plid]); blkg->pd[pol->plid] = NULL; } } spin_unlock_irq(&q->queue_lock); ret = -ENOMEM; goto out; |
a2b1693ba blkcg: implement ... |
1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 |
} EXPORT_SYMBOL_GPL(blkcg_activate_policy); /** * blkcg_deactivate_policy - deactivate a blkcg policy on a request_queue * @q: request_queue of interest * @pol: blkcg policy to deactivate * * Deactivate @pol on @q. Follows the same synchronization rules as * blkcg_activate_policy(). */ void blkcg_deactivate_policy(struct request_queue *q, |
3c798398e blkcg: mass renam... |
1408 |
const struct blkcg_policy *pol) |
a2b1693ba blkcg: implement ... |
1409 |
{ |
3c798398e blkcg: mass renam... |
1410 |
struct blkcg_gq *blkg; |
a2b1693ba blkcg: implement ... |
1411 1412 1413 |
if (!blkcg_policy_enabled(q, pol)) return; |
344e9ffcb block: add queue_... |
1414 |
if (queue_is_mq(q)) |
bd166ef18 blk-mq-sched: add... |
1415 |
blk_mq_freeze_queue(q); |
bd166ef18 blk-mq-sched: add... |
1416 |
|
0d945c1f9 block: remove the... |
1417 |
spin_lock_irq(&q->queue_lock); |
a2b1693ba blkcg: implement ... |
1418 1419 1420 1421 |
__clear_bit(pol->plid, q->blkcg_pols); list_for_each_entry(blkg, &q->blkg_list, q_node) { |
001bea73e blkcg: replace bl... |
1422 |
if (blkg->pd[pol->plid]) { |
6b0654620 Revert "blk-throt... |
1423 |
if (pol->pd_offline_fn) |
a9520cd6f blkcg: make blkcg... |
1424 |
pol->pd_offline_fn(blkg->pd[pol->plid]); |
001bea73e blkcg: replace bl... |
1425 1426 1427 |
pol->pd_free_fn(blkg->pd[pol->plid]); blkg->pd[pol->plid] = NULL; } |
a2b1693ba blkcg: implement ... |
1428 |
} |
0d945c1f9 block: remove the... |
1429 |
spin_unlock_irq(&q->queue_lock); |
bd166ef18 blk-mq-sched: add... |
1430 |
|
344e9ffcb block: add queue_... |
1431 |
if (queue_is_mq(q)) |
bd166ef18 blk-mq-sched: add... |
1432 |
blk_mq_unfreeze_queue(q); |
a2b1693ba blkcg: implement ... |
1433 1434 1435 1436 |
} EXPORT_SYMBOL_GPL(blkcg_deactivate_policy); /** |
3c798398e blkcg: mass renam... |
1437 1438 |
* blkcg_policy_register - register a blkcg policy * @pol: blkcg policy to register |
8bd435b30 blkcg: remove sta... |
1439 |
* |
3c798398e blkcg: mass renam... |
1440 1441 |
* Register @pol with blkcg core. Might sleep and @pol may be modified on * successful registration. Returns 0 on success and -errno on failure. |
8bd435b30 blkcg: remove sta... |
1442 |
*/ |
d5bf02914 Revert "block: ad... |
1443 |
int blkcg_policy_register(struct blkcg_policy *pol) |
3e2520668 blkio: Implement ... |
1444 |
{ |
06b285bd1 blkcg: fix blkcg_... |
1445 |
struct blkcg *blkcg; |
8bd435b30 blkcg: remove sta... |
1446 |
int i, ret; |
e8989fae3 blkcg: unify blkg... |
1447 |
|
838f13bf4 blkcg: allow blkc... |
1448 |
mutex_lock(&blkcg_pol_register_mutex); |
bc0d6501a blkcg: kill blkio... |
1449 |
mutex_lock(&blkcg_pol_mutex); |
8bd435b30 blkcg: remove sta... |
1450 1451 1452 |
/* find an empty slot */ ret = -ENOSPC; for (i = 0; i < BLKCG_MAX_POLS; i++) |
3c798398e blkcg: mass renam... |
1453 |
if (!blkcg_policy[i]) |
8bd435b30 blkcg: remove sta... |
1454 |
break; |
01c5f85ae blk-cgroup: incre... |
1455 1456 1457 |
if (i >= BLKCG_MAX_POLS) { pr_warn("blkcg_policy_register: BLKCG_MAX_POLS too small "); |
838f13bf4 blkcg: allow blkc... |
1458 |
goto err_unlock; |
01c5f85ae blk-cgroup: incre... |
1459 |
} |
035d10b2f blkcg: add blkio_... |
1460 |
|
e84010732 blkcg: add sanity... |
1461 1462 1463 1464 |
/* Make sure cpd/pd_alloc_fn and cpd/pd_free_fn in pairs */ if ((!pol->cpd_alloc_fn ^ !pol->cpd_free_fn) || (!pol->pd_alloc_fn ^ !pol->pd_free_fn)) goto err_unlock; |
06b285bd1 blkcg: fix blkcg_... |
1465 |
/* register @pol */ |
3c798398e blkcg: mass renam... |
1466 |
pol->plid = i; |
06b285bd1 blkcg: fix blkcg_... |
1467 1468 1469 |
blkcg_policy[pol->plid] = pol; /* allocate and install cpd's */ |
e4a9bde95 blkcg: replace bl... |
1470 |
if (pol->cpd_alloc_fn) { |
06b285bd1 blkcg: fix blkcg_... |
1471 1472 |
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) { struct blkcg_policy_data *cpd; |
e4a9bde95 blkcg: replace bl... |
1473 |
cpd = pol->cpd_alloc_fn(GFP_KERNEL); |
bbb427e34 blkcg: Unlock blk... |
1474 |
if (!cpd) |
06b285bd1 blkcg: fix blkcg_... |
1475 |
goto err_free_cpds; |
06b285bd1 blkcg: fix blkcg_... |
1476 |
|
814376483 blkcg: minor upda... |
1477 1478 |
blkcg->cpd[pol->plid] = cpd; cpd->blkcg = blkcg; |
06b285bd1 blkcg: fix blkcg_... |
1479 |
cpd->plid = pol->plid; |
86a5bba5c blkcg: make ->cpd... |
1480 1481 |
if (pol->cpd_init_fn) pol->cpd_init_fn(cpd); |
06b285bd1 blkcg: fix blkcg_... |
1482 1483 |
} } |
838f13bf4 blkcg: allow blkc... |
1484 |
mutex_unlock(&blkcg_pol_mutex); |
8bd435b30 blkcg: remove sta... |
1485 |
|
8bd435b30 blkcg: remove sta... |
1486 |
/* everything is in place, add intf files for the new policy */ |
2ee867dcf blkcg: implement ... |
1487 1488 1489 |
if (pol->dfl_cftypes) WARN_ON(cgroup_add_dfl_cftypes(&io_cgrp_subsys, pol->dfl_cftypes)); |
880f50e22 blkcg: mark exist... |
1490 |
if (pol->legacy_cftypes) |
c165b3e3c blkcg: rename sub... |
1491 |
WARN_ON(cgroup_add_legacy_cftypes(&io_cgrp_subsys, |
880f50e22 blkcg: mark exist... |
1492 |
pol->legacy_cftypes)); |
838f13bf4 blkcg: allow blkc... |
1493 1494 |
mutex_unlock(&blkcg_pol_register_mutex); return 0; |
06b285bd1 blkcg: fix blkcg_... |
1495 |
err_free_cpds: |
58a9edce0 blkcg: check pol-... |
1496 |
if (pol->cpd_free_fn) { |
06b285bd1 blkcg: fix blkcg_... |
1497 |
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) { |
e4a9bde95 blkcg: replace bl... |
1498 1499 1500 1501 |
if (blkcg->cpd[pol->plid]) { pol->cpd_free_fn(blkcg->cpd[pol->plid]); blkcg->cpd[pol->plid] = NULL; } |
06b285bd1 blkcg: fix blkcg_... |
1502 1503 1504 |
} } blkcg_policy[pol->plid] = NULL; |
838f13bf4 blkcg: allow blkc... |
1505 |
err_unlock: |
bc0d6501a blkcg: kill blkio... |
1506 |
mutex_unlock(&blkcg_pol_mutex); |
838f13bf4 blkcg: allow blkc... |
1507 |
mutex_unlock(&blkcg_pol_register_mutex); |
8bd435b30 blkcg: remove sta... |
1508 |
return ret; |
3e2520668 blkio: Implement ... |
1509 |
} |
3c798398e blkcg: mass renam... |
1510 |
EXPORT_SYMBOL_GPL(blkcg_policy_register); |
3e2520668 blkio: Implement ... |
1511 |
|
8bd435b30 blkcg: remove sta... |
1512 |
/** |
3c798398e blkcg: mass renam... |
1513 1514 |
* blkcg_policy_unregister - unregister a blkcg policy * @pol: blkcg policy to unregister |
8bd435b30 blkcg: remove sta... |
1515 |
* |
3c798398e blkcg: mass renam... |
1516 |
* Undo blkcg_policy_register(@pol). Might sleep. |
8bd435b30 blkcg: remove sta... |
1517 |
*/ |
3c798398e blkcg: mass renam... |
1518 |
void blkcg_policy_unregister(struct blkcg_policy *pol) |
3e2520668 blkio: Implement ... |
1519 |
{ |
06b285bd1 blkcg: fix blkcg_... |
1520 |
struct blkcg *blkcg; |
838f13bf4 blkcg: allow blkc... |
1521 |
mutex_lock(&blkcg_pol_register_mutex); |
bc0d6501a blkcg: kill blkio... |
1522 |
|
3c798398e blkcg: mass renam... |
1523 |
if (WARN_ON(blkcg_policy[pol->plid] != pol)) |
8bd435b30 blkcg: remove sta... |
1524 1525 1526 |
goto out_unlock; /* kill the intf files first */ |
2ee867dcf blkcg: implement ... |
1527 1528 |
if (pol->dfl_cftypes) cgroup_rm_cftypes(pol->dfl_cftypes); |
880f50e22 blkcg: mark exist... |
1529 1530 |
if (pol->legacy_cftypes) cgroup_rm_cftypes(pol->legacy_cftypes); |
44ea53de4 blkcg: implement ... |
1531 |
|
06b285bd1 blkcg: fix blkcg_... |
1532 |
/* remove cpds and unregister */ |
838f13bf4 blkcg: allow blkc... |
1533 |
mutex_lock(&blkcg_pol_mutex); |
06b285bd1 blkcg: fix blkcg_... |
1534 |
|
58a9edce0 blkcg: check pol-... |
1535 |
if (pol->cpd_free_fn) { |
06b285bd1 blkcg: fix blkcg_... |
1536 |
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) { |
e4a9bde95 blkcg: replace bl... |
1537 1538 1539 1540 |
if (blkcg->cpd[pol->plid]) { pol->cpd_free_fn(blkcg->cpd[pol->plid]); blkcg->cpd[pol->plid] = NULL; } |
06b285bd1 blkcg: fix blkcg_... |
1541 1542 |
} } |
3c798398e blkcg: mass renam... |
1543 |
blkcg_policy[pol->plid] = NULL; |
06b285bd1 blkcg: fix blkcg_... |
1544 |
|
bc0d6501a blkcg: kill blkio... |
1545 |
mutex_unlock(&blkcg_pol_mutex); |
838f13bf4 blkcg: allow blkc... |
1546 1547 |
out_unlock: mutex_unlock(&blkcg_pol_register_mutex); |
3e2520668 blkio: Implement ... |
1548 |
} |
3c798398e blkcg: mass renam... |
1549 |
EXPORT_SYMBOL_GPL(blkcg_policy_unregister); |
903d23f0a blk-cgroup: allow... |
1550 |
|
d3f77dfdc blkcg: implement ... |
1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 |
bool __blkcg_punt_bio_submit(struct bio *bio) { struct blkcg_gq *blkg = bio->bi_blkg; /* consume the flag first */ bio->bi_opf &= ~REQ_CGROUP_PUNT; /* never bounce for the root cgroup */ if (!blkg->parent) return false; spin_lock_bh(&blkg->async_bio_lock); bio_list_add(&blkg->async_bios, bio); spin_unlock_bh(&blkg->async_bio_lock); queue_work(blkcg_punt_bio_wq, &blkg->async_bio_work); return true; } |
d09d8df3a blkcg: add generi... |
1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 |
/* * Scale the accumulated delay based on how long it has been since we updated * the delay. We only call this when we are adding delay, in case it's been a * while since we added delay, and when we are checking to see if we need to * delay a task, to account for any delays that may have occurred. */ static void blkcg_scale_delay(struct blkcg_gq *blkg, u64 now) { u64 old = atomic64_read(&blkg->delay_start); /* * We only want to scale down every second. The idea here is that we * want to delay people for min(delay_nsec, NSEC_PER_SEC) in a certain * time window. We only want to throttle tasks for recent delay that * has occurred, in 1 second time windows since that's the maximum * things can be throttled. We save the current delay window in * blkg->last_delay so we know what amount is still left to be charged * to the blkg from this point onward. blkg->last_use keeps track of * the use_delay counter. The idea is if we're unthrottling the blkg we * are ok with whatever is happening now, and we can take away more of * the accumulated delay as we've already throttled enough that * everybody is happy with their IO latencies. */ if (time_before64(old + NSEC_PER_SEC, now) && atomic64_cmpxchg(&blkg->delay_start, old, now) == old) { u64 cur = atomic64_read(&blkg->delay_nsec); u64 sub = min_t(u64, blkg->last_delay, now - old); int cur_use = atomic_read(&blkg->use_delay); /* * We've been unthrottled, subtract a larger chunk of our * accumulated delay. */ if (cur_use < blkg->last_use) sub = max_t(u64, sub, blkg->last_delay >> 1); /* * This shouldn't happen, but handle it anyway. Our delay_nsec * should only ever be growing except here where we subtract out * min(last_delay, 1 second), but lord knows bugs happen and I'd * rather not end up with negative numbers. */ if (unlikely(cur < sub)) { atomic64_set(&blkg->delay_nsec, 0); blkg->last_delay = 0; } else { atomic64_sub(sub, &blkg->delay_nsec); blkg->last_delay = cur - sub; } blkg->last_use = cur_use; } } /* * This is called when we want to actually walk up the hierarchy and check to * see if we need to throttle, and then actually throttle if there is some * accumulated delay. This should only be called upon return to user space so * we're not holding some lock that would induce a priority inversion. */ static void blkcg_maybe_throttle_blkg(struct blkcg_gq *blkg, bool use_memdelay) { |
fd112c746 blk-cgroup: turn ... |
1630 |
unsigned long pflags; |
d09d8df3a blkcg: add generi... |
1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 |
u64 now = ktime_to_ns(ktime_get()); u64 exp; u64 delay_nsec = 0; int tok; while (blkg->parent) { if (atomic_read(&blkg->use_delay)) { blkcg_scale_delay(blkg, now); delay_nsec = max_t(u64, delay_nsec, atomic64_read(&blkg->delay_nsec)); } blkg = blkg->parent; } if (!delay_nsec) return; /* * Let's not sleep for all eternity if we've amassed a huge delay. * Swapping or metadata IO can accumulate 10's of seconds worth of * delay, and we want userspace to be able to do _something_ so cap the * delays at 1 second. If there's 10's of seconds worth of delay then * the tasks will be delayed for 1 second for every syscall. */ delay_nsec = min_t(u64, delay_nsec, 250 * NSEC_PER_MSEC); |
fd112c746 blk-cgroup: turn ... |
1656 1657 |
if (use_memdelay) psi_memstall_enter(&pflags); |
d09d8df3a blkcg: add generi... |
1658 1659 1660 1661 1662 1663 1664 1665 1666 |
exp = ktime_add_ns(now, delay_nsec); tok = io_schedule_prepare(); do { __set_current_state(TASK_KILLABLE); if (!schedule_hrtimeout(&exp, HRTIMER_MODE_ABS)) break; } while (!fatal_signal_pending(current)); io_schedule_finish(tok); |
fd112c746 blk-cgroup: turn ... |
1667 1668 1669 |
if (use_memdelay) psi_memstall_leave(&pflags); |
d09d8df3a blkcg: add generi... |
1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 |
} /** * blkcg_maybe_throttle_current - throttle the current task if it has been marked * * This is only called if we've been marked with set_notify_resume(). Obviously * we can be set_notify_resume() for reasons other than blkcg throttling, so we * check to see if current->throttle_queue is set and if not this doesn't do * anything. This should only ever be called by the resume code, it's not meant * to be called by people willy-nilly as it will actually do the work to * throttle the task if it is setup for throttling. */ void blkcg_maybe_throttle_current(void) { struct request_queue *q = current->throttle_queue; struct cgroup_subsys_state *css; struct blkcg *blkcg; struct blkcg_gq *blkg; bool use_memdelay = current->use_memdelay; if (!q) return; current->throttle_queue = NULL; current->use_memdelay = false; rcu_read_lock(); css = kthread_blkcg(); if (css) blkcg = css_to_blkcg(css); else blkcg = css_to_blkcg(task_css(current, io_cgrp_id)); if (!blkcg) goto out; blkg = blkg_lookup(blkcg, q); if (!blkg) goto out; |
7754f669f blkcg: rename blk... |
1708 |
if (!blkg_tryget(blkg)) |
d09d8df3a blkcg: add generi... |
1709 1710 |
goto out; rcu_read_unlock(); |
d09d8df3a blkcg: add generi... |
1711 1712 1713 |
blkcg_maybe_throttle_blkg(blkg, use_memdelay); blkg_put(blkg); |
cc7ecc258 blk-cgroup: hold ... |
1714 |
blk_put_queue(q); |
d09d8df3a blkcg: add generi... |
1715 1716 1717 1718 1719 |
return; out: rcu_read_unlock(); blk_put_queue(q); } |
d09d8df3a blkcg: add generi... |
1720 1721 1722 |
/** * blkcg_schedule_throttle - this task needs to check for throttling |
537d71b3f blkcg: Fix kernel... |
1723 1724 |
* @q: the request queue IO was submitted on * @use_memdelay: do we charge this to memory delay for PSI |
d09d8df3a blkcg: add generi... |
1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 |
* * This is called by the IO controller when we know there's delay accumulated * for the blkg for this task. We do not pass the blkg because there are places * we call this that may not have that information, the swapping code for * instance will only have a request_queue at that point. This set's the * notify_resume for the task to check and see if it requires throttling before * returning to user space. * * We will only schedule once per syscall. You can call this over and over * again and it will only do the check once upon return to user space, and only * throttle once. If the task needs to be throttled again it'll need to be * re-set at the next time we see the task. */ void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay) { if (unlikely(current->flags & PF_KTHREAD)) return; if (!blk_get_queue(q)) return; if (current->throttle_queue) blk_put_queue(current->throttle_queue); current->throttle_queue = q; if (use_memdelay) current->use_memdelay = use_memdelay; set_notify_resume(current); } |
d09d8df3a blkcg: add generi... |
1753 1754 1755 |
/** * blkcg_add_delay - add delay to this blkg |
537d71b3f blkcg: Fix kernel... |
1756 1757 1758 |
* @blkg: blkg of interest * @now: the current time in nanoseconds * @delta: how many nanoseconds of delay to add |
d09d8df3a blkcg: add generi... |
1759 1760 1761 1762 1763 1764 1765 1766 1767 |
* * Charge @delta to the blkg's current delay accumulation. This is used to * throttle tasks if an IO controller thinks we need more throttling. */ void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta) { blkcg_scale_delay(blkg, now); atomic64_add(delta, &blkg->delay_nsec); } |
d09d8df3a blkcg: add generi... |
1768 |
|
d3f77dfdc blkcg: implement ... |
1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 |
static int __init blkcg_init(void) { blkcg_punt_bio_wq = alloc_workqueue("blkcg_punt_bio", WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND | WQ_SYSFS, 0); if (!blkcg_punt_bio_wq) return -ENOMEM; return 0; } subsys_initcall(blkcg_init); |
903d23f0a blk-cgroup: allow... |
1779 1780 |
module_param(blkcg_debug_stats, bool, 0644); MODULE_PARM_DESC(blkcg_debug_stats, "True if you want debug stats, false if not"); |