[PATCH] deadline-iosched: migrate to using the elevator rb functions

This removes the rbtree handling from deadline. Signed-off-by: Jens Axboe <axboe@suse.de>

[PATCH] deadline-iosched: migrate to using the elevator rb functions
This removes the rbtree handling from deadline. Signed-off-by: Jens Axboe <axboe@suse.de>
Jens Axboe · Jens Axboe
1 parent 21183b07ee
Showing 1 changed file with 34 additions and 136 deletions Side-by-side Diff
block/deadline-iosched.c
@@ -57,12 +57,6 @@
  * pre-request data.
  */
 struct deadline_rq {
-	/*
-	 * rbtree index, key is the starting offset
-	 */
-	struct rb_node rb_node;
-	sector_t rb_key;
-
 	struct request *request;
  
 	/*
  
  
  
  
  
  
  
  
  
  
  
  
@@ -78,111 +72,41 @@
  
 #define RQ_DATA(rq)	((struct deadline_rq *) (rq)->elevator_private)
  
-/*
- * rb tree support functions
- */
-#define rb_entry_drq(node)	rb_entry((node), struct deadline_rq, rb_node)
-#define DRQ_RB_ROOT(dd, drq)	(&(dd)->sort_list[rq_data_dir((drq)->request)])
-#define rq_rb_key(rq)		(rq)->sector
+#define RQ_RB_ROOT(dd, rq)	(&(dd)->sort_list[rq_data_dir((rq))])
+#define DRQ_RB_ROOT(dd, drq)	RQ_RB_ROOT((drq)->request)
  
-static struct deadline_rq *
-__deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
-{
-	struct rb_node **p = &DRQ_RB_ROOT(dd, drq)->rb_node;
-	struct rb_node *parent = NULL;
-	struct deadline_rq *__drq;
-
-	while (*p) {
-		parent = *p;
-		__drq = rb_entry_drq(parent);
-
-		if (drq->rb_key < __drq->rb_key)
-			p = &(*p)->rb_left;
-		else if (drq->rb_key > __drq->rb_key)
-			p = &(*p)->rb_right;
-		else
-			return __drq;
-	}
-
-	rb_link_node(&drq->rb_node, parent, p);
-	return NULL;
-}
-
 static void
-deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
+deadline_add_drq_rb(struct deadline_data *dd, struct request *rq)
 {
-	struct deadline_rq *__alias;
+	struct rb_root *root = RQ_RB_ROOT(dd, rq);
+	struct request *__alias;
  
-	drq->rb_key = rq_rb_key(drq->request);
-
 retry:
-	__alias = __deadline_add_drq_rb(dd, drq);
-	if (!__alias) {
-		rb_insert_color(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
-		return;
+	__alias = elv_rb_add(root, rq);
+	if (unlikely(__alias)) {
+		deadline_move_request(dd, RQ_DATA(__alias));
+		goto retry;
 	}
-
-	deadline_move_request(dd, __alias);
-	goto retry;
 }
  
 static inline void
 deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
 {
-	const int data_dir = rq_data_dir(drq->request);
+	struct request *rq = drq->request;
+	const int data_dir = rq_data_dir(rq);
  
 	if (dd->next_drq[data_dir] == drq) {
-		struct rb_node *rbnext = rb_next(&drq->rb_node);
+		struct rb_node *rbnext = rb_next(&rq->rb_node);
  
 		dd->next_drq[data_dir] = NULL;
 		if (rbnext)
-			dd->next_drq[data_dir] = rb_entry_drq(rbnext);
+			dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));
 	}
  
-	BUG_ON(!RB_EMPTY_NODE(&drq->rb_node));
-	rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
-	RB_CLEAR_NODE(&drq->rb_node);
+	elv_rb_del(RQ_RB_ROOT(dd, rq), rq);
 }
  
-static struct request *
-deadline_find_drq_rb(struct deadline_data *dd, sector_t sector, int data_dir)
-{
-	struct rb_node *n = dd->sort_list[data_dir].rb_node;
-	struct deadline_rq *drq;
-
-	while (n) {
-		drq = rb_entry_drq(n);
-
-		if (sector < drq->rb_key)
-			n = n->rb_left;
-		else if (sector > drq->rb_key)
-			n = n->rb_right;
-		else
-			return drq->request;
-	}
-
-	return NULL;
-}
-
 /*
- * deadline_find_first_drq finds the first (lowest sector numbered) request
- * for the specified data_dir. Used to sweep back to the start of the disk
- * (1-way elevator) after we process the last (highest sector) request.
- */
-static struct deadline_rq *
-deadline_find_first_drq(struct deadline_data *dd, int data_dir)
-{
-	struct rb_node *n = dd->sort_list[data_dir].rb_node;
-
-	for (;;) {
-		if (n->rb_left == NULL)
-			return rb_entry_drq(n);
-		
-		n = n->rb_left;
-	}
-}
-
-/*
  * add drq to rbtree and fifo
  */
 static void
@@ -192,7 +116,7 @@
 	struct deadline_rq *drq = RQ_DATA(rq);
 	const int data_dir = rq_data_dir(drq->request);
  
-	deadline_add_drq_rb(dd, drq);
+	deadline_add_drq_rb(dd, rq);
  
 	/*
 	 * set expire time (only used for reads) and add to fifo list
  
  
@@ -224,11 +148,11 @@
 	 * check for front merge
 	 */
 	if (dd->front_merges) {
-		sector_t rb_key = bio->bi_sector + bio_sectors(bio);
+		sector_t sector = bio->bi_sector + bio_sectors(bio);
  
-		__rq = deadline_find_drq_rb(dd, rb_key, bio_data_dir(bio));
+		__rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
 		if (__rq) {
-			BUG_ON(rb_key != rq_rb_key(__rq));
+			BUG_ON(sector != __rq->sector);
  
 			if (elv_rq_merge_ok(__rq, bio)) {
 				ret = ELEVATOR_FRONT_MERGE;
  
  
@@ -243,17 +167,17 @@
 	return ret;
 }
  
-static void deadline_merged_request(request_queue_t *q, struct request *req)
+static void deadline_merged_request(request_queue_t *q, struct request *req,
+				    int type)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
-	struct deadline_rq *drq = RQ_DATA(req);
  
 	/*
 	 * if the merge was a front merge, we need to reposition request
 	 */
-	if (rq_rb_key(req) != drq->rb_key) {
-		deadline_del_drq_rb(dd, drq);
-		deadline_add_drq_rb(dd, drq);
+	if (type == ELEVATOR_FRONT_MERGE) {
+		elv_rb_del(RQ_RB_ROOT(dd, req), req);
+		deadline_add_drq_rb(dd, req);
 	}
 }
  
  
@@ -261,18 +185,12 @@
 deadline_merged_requests(request_queue_t *q, struct request *req,
 			 struct request *next)
 {
-	struct deadline_data *dd = q->elevator->elevator_data;
 	struct deadline_rq *drq = RQ_DATA(req);
 	struct deadline_rq *dnext = RQ_DATA(next);
  
 	BUG_ON(!drq);
 	BUG_ON(!dnext);
  
-	if (rq_rb_key(req) != drq->rb_key) {
-		deadline_del_drq_rb(dd, drq);
-		deadline_add_drq_rb(dd, drq);
-	}
-
 	/*
 	 * if dnext expires before drq, assign its expire time to drq
 	 * and move into dnext position (dnext will be deleted) in fifo
  
@@ -308,14 +226,15 @@
 static void
 deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq)
 {
-	const int data_dir = rq_data_dir(drq->request);
-	struct rb_node *rbnext = rb_next(&drq->rb_node);
+	struct request *rq = drq->request;
+	const int data_dir = rq_data_dir(rq);
+	struct rb_node *rbnext = rb_next(&rq->rb_node);
  
 	dd->next_drq[READ] = NULL;
 	dd->next_drq[WRITE] = NULL;
  
 	if (rbnext)
-		dd->next_drq[data_dir] = rb_entry_drq(rbnext);
+		dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));
  
 	dd->last_sector = drq->request->sector + drq->request->nr_sectors;
  
  
@@ -426,13 +345,17 @@
 		 */
 		drq = dd->next_drq[data_dir];
 	} else {
+		struct rb_node *n;
+
 		/*
 		 * The last req was the other direction or we have run out of
 		 * higher-sectored requests. Go back to the lowest sectored
 		 * request (1 way elevator) and start a new batch.
 		 */
 		dd->batching = 0;
-		drq = deadline_find_first_drq(dd, data_dir);
+		n = rb_first(&dd->sort_list[data_dir]);
+		if (n)
+			drq = RQ_DATA(rb_entry_rq(n));
 	}
  
 dispatch_request:
@@ -453,30 +376,6 @@
 		&& list_empty(&dd->fifo_list[READ]);
 }
  
-static struct request *
-deadline_former_request(request_queue_t *q, struct request *rq)
-{
-	struct deadline_rq *drq = RQ_DATA(rq);
-	struct rb_node *rbprev = rb_prev(&drq->rb_node);
-
-	if (rbprev)
-		return rb_entry_drq(rbprev)->request;
-
-	return NULL;
-}
-
-static struct request *
-deadline_latter_request(request_queue_t *q, struct request *rq)
-{
-	struct deadline_rq *drq = RQ_DATA(rq);
-	struct rb_node *rbnext = rb_next(&drq->rb_node);
-
-	if (rbnext)
-		return rb_entry_drq(rbnext)->request;
-
-	return NULL;
-}
-
 static void deadline_exit_queue(elevator_t *e)
 {
 	struct deadline_data *dd = e->elevator_data;
@@ -542,7 +441,6 @@
 	drq = mempool_alloc(dd->drq_pool, gfp_mask);
 	if (drq) {
 		memset(drq, 0, sizeof(*drq));
-		RB_CLEAR_NODE(&drq->rb_node);
 		drq->request = rq;
  
 		INIT_LIST_HEAD(&drq->fifo);
@@ -633,8 +531,8 @@
 		.elevator_dispatch_fn =		deadline_dispatch_requests,
 		.elevator_add_req_fn =		deadline_add_request,
 		.elevator_queue_empty_fn =	deadline_queue_empty,
-		.elevator_former_req_fn =	deadline_former_request,
-		.elevator_latter_req_fn =	deadline_latter_request,
+		.elevator_former_req_fn =	elv_rb_former_request,
+		.elevator_latter_req_fn =	elv_rb_latter_request,
 		.elevator_set_req_fn =		deadline_set_request,
 		.elevator_put_req_fn = 		deadline_put_request,
 		.elevator_init_fn =		deadline_init_queue,
...	...	@@ -57,12 +57,6 @@
57	57	* pre-request data.
58	58	*/
59	59	struct deadline_rq {
60		- /*
61		- * rbtree index, key is the starting offset
62		- */
63		- struct rb_node rb_node;
64		- sector_t rb_key;
65		-
66	60	struct request *request;
67	61
68	62	/*
69	63
70	64
71	65
72	66
73	67
74	68
75	69
76	70
77	71
78	72
79	73
80	74
...	...	@@ -78,111 +72,41 @@
78	72
79	73	#define RQ_DATA(rq) ((struct deadline_rq *) (rq)->elevator_private)
80	74
81		-/*
82		- * rb tree support functions
83		- */
84		-#define rb_entry_drq(node) rb_entry((node), struct deadline_rq, rb_node)
85		-#define DRQ_RB_ROOT(dd, drq) (&(dd)->sort_list[rq_data_dir((drq)->request)])
86		-#define rq_rb_key(rq) (rq)->sector
	75	+#define RQ_RB_ROOT(dd, rq) (&(dd)->sort_list[rq_data_dir((rq))])
	76	+#define DRQ_RB_ROOT(dd, drq) RQ_RB_ROOT((drq)->request)
87	77
88		-static struct deadline_rq *
89		-__deadline_add_drq_rb(struct deadline_data dd, struct deadline_rq drq)
90		-{
91		- struct rb_node **p = &DRQ_RB_ROOT(dd, drq)->rb_node;
92		- struct rb_node *parent = NULL;
93		- struct deadline_rq *__drq;
94		-
95		- while (*p) {
96		- parent = *p;
97		- __drq = rb_entry_drq(parent);
98		-
99		- if (drq->rb_key < __drq->rb_key)
100		- p = &(*p)->rb_left;
101		- else if (drq->rb_key > __drq->rb_key)
102		- p = &(*p)->rb_right;
103		- else
104		- return __drq;
105		- }
106		-
107		- rb_link_node(&drq->rb_node, parent, p);
108		- return NULL;
109		-}
110		-
111	78	static void
112		-deadline_add_drq_rb(struct deadline_data dd, struct deadline_rq drq)
	79	+deadline_add_drq_rb(struct deadline_data dd, struct request rq)
113	80	{
114		- struct deadline_rq *__alias;
	81	+ struct rb_root *root = RQ_RB_ROOT(dd, rq);
	82	+ struct request *__alias;
115	83
116		- drq->rb_key = rq_rb_key(drq->request);
117		-
118	84	retry:
119		- __alias = __deadline_add_drq_rb(dd, drq);
120		- if (!__alias) {
121		- rb_insert_color(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
122		- return;
	85	+ __alias = elv_rb_add(root, rq);
	86	+ if (unlikely(__alias)) {
	87	+ deadline_move_request(dd, RQ_DATA(__alias));
	88	+ goto retry;
123	89	}
124		-
125		- deadline_move_request(dd, __alias);
126		- goto retry;
127	90	}
128	91
129	92	static inline void
130	93	deadline_del_drq_rb(struct deadline_data dd, struct deadline_rq drq)
131	94	{
132		- const int data_dir = rq_data_dir(drq->request);
	95	+ struct request *rq = drq->request;
	96	+ const int data_dir = rq_data_dir(rq);
133	97
134	98	if (dd->next_drq[data_dir] == drq) {
135		- struct rb_node *rbnext = rb_next(&drq->rb_node);
	99	+ struct rb_node *rbnext = rb_next(&rq->rb_node);
136	100
137	101	dd->next_drq[data_dir] = NULL;
138	102	if (rbnext)
139		- dd->next_drq[data_dir] = rb_entry_drq(rbnext);
	103	+ dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));
140	104	}
141	105
142		- BUG_ON(!RB_EMPTY_NODE(&drq->rb_node));
143		- rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
144		- RB_CLEAR_NODE(&drq->rb_node);
	106	+ elv_rb_del(RQ_RB_ROOT(dd, rq), rq);
145	107	}
146	108
147		-static struct request *
148		-deadline_find_drq_rb(struct deadline_data *dd, sector_t sector, int data_dir)
149		-{
150		- struct rb_node *n = dd->sort_list[data_dir].rb_node;
151		- struct deadline_rq *drq;
152		-
153		- while (n) {
154		- drq = rb_entry_drq(n);
155		-
156		- if (sector < drq->rb_key)
157		- n = n->rb_left;
158		- else if (sector > drq->rb_key)
159		- n = n->rb_right;
160		- else
161		- return drq->request;
162		- }
163		-
164		- return NULL;
165		-}
166		-
167	109	/*
168		- * deadline_find_first_drq finds the first (lowest sector numbered) request
169		- * for the specified data_dir. Used to sweep back to the start of the disk
170		- * (1-way elevator) after we process the last (highest sector) request.
171		- */
172		-static struct deadline_rq *
173		-deadline_find_first_drq(struct deadline_data *dd, int data_dir)
174		-{
175		- struct rb_node *n = dd->sort_list[data_dir].rb_node;
176		-
177		- for (;;) {
178		- if (n->rb_left == NULL)
179		- return rb_entry_drq(n);
180		-
181		- n = n->rb_left;
182		- }
183		-}
184		-
185		-/*
186	110	* add drq to rbtree and fifo
187	111	*/
188	112	static void
...	...	@@ -192,7 +116,7 @@
192	116	struct deadline_rq *drq = RQ_DATA(rq);
193	117	const int data_dir = rq_data_dir(drq->request);
194	118
195		- deadline_add_drq_rb(dd, drq);
	119	+ deadline_add_drq_rb(dd, rq);
196	120
197	121	/*
198	122	* set expire time (only used for reads) and add to fifo list
199	123
200	124
...	...	@@ -224,11 +148,11 @@
224	148	* check for front merge
225	149	*/
226	150	if (dd->front_merges) {
227		- sector_t rb_key = bio->bi_sector + bio_sectors(bio);
	151	+ sector_t sector = bio->bi_sector + bio_sectors(bio);
228	152
229		- __rq = deadline_find_drq_rb(dd, rb_key, bio_data_dir(bio));
	153	+ __rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
230	154	if (__rq) {
231		- BUG_ON(rb_key != rq_rb_key(__rq));
	155	+ BUG_ON(sector != __rq->sector);
232	156
233	157	if (elv_rq_merge_ok(__rq, bio)) {
234	158	ret = ELEVATOR_FRONT_MERGE;
235	159
236	160
...	...	@@ -243,17 +167,17 @@
243	167	return ret;
244	168	}
245	169
246		-static void deadline_merged_request(request_queue_t q, struct request req)
	170	+static void deadline_merged_request(request_queue_t q, struct request req,
	171	+ int type)
247	172	{
248	173	struct deadline_data *dd = q->elevator->elevator_data;
249		- struct deadline_rq *drq = RQ_DATA(req);
250	174
251	175	/*
252	176	* if the merge was a front merge, we need to reposition request
253	177	*/
254		- if (rq_rb_key(req) != drq->rb_key) {
255		- deadline_del_drq_rb(dd, drq);
256		- deadline_add_drq_rb(dd, drq);
	178	+ if (type == ELEVATOR_FRONT_MERGE) {
	179	+ elv_rb_del(RQ_RB_ROOT(dd, req), req);
	180	+ deadline_add_drq_rb(dd, req);
257	181	}
258	182	}
259	183
260	184
...	...	@@ -261,18 +185,12 @@
261	185	deadline_merged_requests(request_queue_t q, struct request req,
262	186	struct request *next)
263	187	{
264		- struct deadline_data *dd = q->elevator->elevator_data;
265	188	struct deadline_rq *drq = RQ_DATA(req);
266	189	struct deadline_rq *dnext = RQ_DATA(next);
267	190
268	191	BUG_ON(!drq);
269	192	BUG_ON(!dnext);
270	193
271		- if (rq_rb_key(req) != drq->rb_key) {
272		- deadline_del_drq_rb(dd, drq);
273		- deadline_add_drq_rb(dd, drq);
274		- }
275		-
276	194	/*
277	195	* if dnext expires before drq, assign its expire time to drq
278	196	* and move into dnext position (dnext will be deleted) in fifo
279	197
...	...	@@ -308,14 +226,15 @@
308	226	static void
309	227	deadline_move_request(struct deadline_data dd, struct deadline_rq drq)
310	228	{
311		- const int data_dir = rq_data_dir(drq->request);
312		- struct rb_node *rbnext = rb_next(&drq->rb_node);
	229	+ struct request *rq = drq->request;
	230	+ const int data_dir = rq_data_dir(rq);
	231	+ struct rb_node *rbnext = rb_next(&rq->rb_node);
313	232
314	233	dd->next_drq[READ] = NULL;
315	234	dd->next_drq[WRITE] = NULL;
316	235
317	236	if (rbnext)
318		- dd->next_drq[data_dir] = rb_entry_drq(rbnext);
	237	+ dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));
319	238
320	239	dd->last_sector = drq->request->sector + drq->request->nr_sectors;
321	240
322	241
...	...	@@ -426,13 +345,17 @@
426	345	*/
427	346	drq = dd->next_drq[data_dir];
428	347	} else {
	348	+ struct rb_node *n;
	349	+
429	350	/*
430	351	* The last req was the other direction or we have run out of
431	352	* higher-sectored requests. Go back to the lowest sectored
432	353	* request (1 way elevator) and start a new batch.
433	354	*/
434	355	dd->batching = 0;
435		- drq = deadline_find_first_drq(dd, data_dir);
	356	+ n = rb_first(&dd->sort_list[data_dir]);
	357	+ if (n)
	358	+ drq = RQ_DATA(rb_entry_rq(n));
436	359	}
437	360
438	361	dispatch_request:
...	...	@@ -453,30 +376,6 @@
453	376	&& list_empty(&dd->fifo_list[READ]);
454	377	}
455	378
456		-static struct request *
457		-deadline_former_request(request_queue_t q, struct request rq)
458		-{
459		- struct deadline_rq *drq = RQ_DATA(rq);
460		- struct rb_node *rbprev = rb_prev(&drq->rb_node);
461		-
462		- if (rbprev)
463		- return rb_entry_drq(rbprev)->request;
464		-
465		- return NULL;
466		-}
467		-
468		-static struct request *
469		-deadline_latter_request(request_queue_t q, struct request rq)
470		-{
471		- struct deadline_rq *drq = RQ_DATA(rq);
472		- struct rb_node *rbnext = rb_next(&drq->rb_node);
473		-
474		- if (rbnext)
475		- return rb_entry_drq(rbnext)->request;
476		-
477		- return NULL;
478		-}
479		-
480	379	static void deadline_exit_queue(elevator_t *e)
481	380	{
482	381	struct deadline_data *dd = e->elevator_data;
...	...	@@ -542,7 +441,6 @@
542	441	drq = mempool_alloc(dd->drq_pool, gfp_mask);
543	442	if (drq) {
544	443	memset(drq, 0, sizeof(*drq));
545		- RB_CLEAR_NODE(&drq->rb_node);
546	444	drq->request = rq;
547	445
548	446	INIT_LIST_HEAD(&drq->fifo);
...	...	@@ -633,8 +531,8 @@
633	531	.elevator_dispatch_fn = deadline_dispatch_requests,
634	532	.elevator_add_req_fn = deadline_add_request,
635	533	.elevator_queue_empty_fn = deadline_queue_empty,
636		- .elevator_former_req_fn = deadline_former_request,
637		- .elevator_latter_req_fn = deadline_latter_request,
	534	+ .elevator_former_req_fn = elv_rb_former_request,
	535	+ .elevator_latter_req_fn = elv_rb_latter_request,
638	536	.elevator_set_req_fn = deadline_set_request,
639	537	.elevator_put_req_fn = deadline_put_request,
640	538	.elevator_init_fn = deadline_init_queue,