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authorJens Axboe <axboe@suse.de>2006-07-13 06:34:24 -0400
committerJens Axboe <axboe@nelson.home.kernel.dk>2006-09-30 14:26:58 -0400
commitb8aca35af5e9fbc2e41a3ba1b2e66f24e80ca9b6 (patch)
treecb25861431d320eade140875bdd326faa0de19e2 /block
parent21183b07ee4be405362af8454f3647781c77df1b (diff)
[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>
Diffstat (limited to 'block')
-rw-r--r--block/deadline-iosched.c170
1 files changed, 34 insertions, 136 deletions
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index b66e820f544d..8300ba1f15a0 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -57,12 +57,6 @@ struct deadline_data {
57 * pre-request data. 57 * pre-request data.
58 */ 58 */
59struct deadline_rq { 59struct 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 struct request *request; 60 struct request *request;
67 61
68 /* 62 /*
@@ -78,108 +72,38 @@ static kmem_cache_t *drq_pool;
78 72
79#define RQ_DATA(rq) ((struct deadline_rq *) (rq)->elevator_private) 73#define RQ_DATA(rq) ((struct deadline_rq *) (rq)->elevator_private)
80 74
81/* 75#define RQ_RB_ROOT(dd, rq) (&(dd)->sort_list[rq_data_dir((rq))])
82 * rb tree support functions 76#define DRQ_RB_ROOT(dd, drq) RQ_RB_ROOT((drq)->request)
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
87
88static 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 77
111static void 78static void
112deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq) 79deadline_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);
115 82 struct request *__alias;
116 drq->rb_key = rq_rb_key(drq->request);
117 83
118retry: 84retry:
119 __alias = __deadline_add_drq_rb(dd, drq); 85 __alias = elv_rb_add(root, rq);
120 if (!__alias) { 86 if (unlikely(__alias)) {
121 rb_insert_color(&drq->rb_node, DRQ_RB_ROOT(dd, drq)); 87 deadline_move_request(dd, RQ_DATA(__alias));
122 return; 88 goto retry;
123 } 89 }
124
125 deadline_move_request(dd, __alias);
126 goto retry;
127} 90}
128 91
129static inline void 92static inline void
130deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq) 93deadline_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 if (dd->next_drq[data_dir] == drq) { 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 dd->next_drq[data_dir] = NULL; 101 dd->next_drq[data_dir] = NULL;
138 if (rbnext) 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 }
141
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);
145}
146
147static struct request *
148deadline_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 } 104 }
163 105
164 return NULL; 106 elv_rb_del(RQ_RB_ROOT(dd, rq), rq);
165}
166
167/*
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 */
172static struct deadline_rq *
173deadline_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} 107}
184 108
185/* 109/*
@@ -192,7 +116,7 @@ deadline_add_request(struct request_queue *q, struct request *rq)
192 struct deadline_rq *drq = RQ_DATA(rq); 116 struct deadline_rq *drq = RQ_DATA(rq);
193 const int data_dir = rq_data_dir(drq->request); 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 * set expire time (only used for reads) and add to fifo list 122 * set expire time (only used for reads) and add to fifo list
@@ -224,11 +148,11 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
224 * check for front merge 148 * check for front merge
225 */ 149 */
226 if (dd->front_merges) { 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 if (__rq) { 154 if (__rq) {
231 BUG_ON(rb_key != rq_rb_key(__rq)); 155 BUG_ON(sector != __rq->sector);
232 156
233 if (elv_rq_merge_ok(__rq, bio)) { 157 if (elv_rq_merge_ok(__rq, bio)) {
234 ret = ELEVATOR_FRONT_MERGE; 158 ret = ELEVATOR_FRONT_MERGE;
@@ -243,17 +167,17 @@ out:
243 return ret; 167 return ret;
244} 168}
245 169
246static void deadline_merged_request(request_queue_t *q, struct request *req) 170static void deadline_merged_request(request_queue_t *q, struct request *req,
171 int type)
247{ 172{
248 struct deadline_data *dd = q->elevator->elevator_data; 173 struct deadline_data *dd = q->elevator->elevator_data;
249 struct deadline_rq *drq = RQ_DATA(req);
250 174
251 /* 175 /*
252 * if the merge was a front merge, we need to reposition request 176 * if the merge was a front merge, we need to reposition request
253 */ 177 */
254 if (rq_rb_key(req) != drq->rb_key) { 178 if (type == ELEVATOR_FRONT_MERGE) {
255 deadline_del_drq_rb(dd, drq); 179 elv_rb_del(RQ_RB_ROOT(dd, req), req);
256 deadline_add_drq_rb(dd, drq); 180 deadline_add_drq_rb(dd, req);
257 } 181 }
258} 182}
259 183
@@ -261,18 +185,12 @@ static void
261deadline_merged_requests(request_queue_t *q, struct request *req, 185deadline_merged_requests(request_queue_t *q, struct request *req,
262 struct request *next) 186 struct request *next)
263{ 187{
264 struct deadline_data *dd = q->elevator->elevator_data;
265 struct deadline_rq *drq = RQ_DATA(req); 188 struct deadline_rq *drq = RQ_DATA(req);
266 struct deadline_rq *dnext = RQ_DATA(next); 189 struct deadline_rq *dnext = RQ_DATA(next);
267 190
268 BUG_ON(!drq); 191 BUG_ON(!drq);
269 BUG_ON(!dnext); 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 * if dnext expires before drq, assign its expire time to drq 195 * if dnext expires before drq, assign its expire time to drq
278 * and move into dnext position (dnext will be deleted) in fifo 196 * and move into dnext position (dnext will be deleted) in fifo
@@ -308,14 +226,15 @@ deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq)
308static void 226static void
309deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq) 227deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq)
310{ 228{
311 const int data_dir = rq_data_dir(drq->request); 229 struct request *rq = drq->request;
312 struct rb_node *rbnext = rb_next(&drq->rb_node); 230 const int data_dir = rq_data_dir(rq);
231 struct rb_node *rbnext = rb_next(&rq->rb_node);
313 232
314 dd->next_drq[READ] = NULL; 233 dd->next_drq[READ] = NULL;
315 dd->next_drq[WRITE] = NULL; 234 dd->next_drq[WRITE] = NULL;
316 235
317 if (rbnext) 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 dd->last_sector = drq->request->sector + drq->request->nr_sectors; 239 dd->last_sector = drq->request->sector + drq->request->nr_sectors;
321 240
@@ -426,13 +345,17 @@ dispatch_find_request:
426 */ 345 */
427 drq = dd->next_drq[data_dir]; 346 drq = dd->next_drq[data_dir];
428 } else { 347 } else {
348 struct rb_node *n;
349
429 /* 350 /*
430 * The last req was the other direction or we have run out of 351 * The last req was the other direction or we have run out of
431 * higher-sectored requests. Go back to the lowest sectored 352 * higher-sectored requests. Go back to the lowest sectored
432 * request (1 way elevator) and start a new batch. 353 * request (1 way elevator) and start a new batch.
433 */ 354 */
434 dd->batching = 0; 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
438dispatch_request: 361dispatch_request:
@@ -453,30 +376,6 @@ static int deadline_queue_empty(request_queue_t *q)
453 && list_empty(&dd->fifo_list[READ]); 376 && list_empty(&dd->fifo_list[READ]);
454} 377}
455 378
456static struct request *
457deadline_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
468static struct request *
469deadline_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
480static void deadline_exit_queue(elevator_t *e) 379static void deadline_exit_queue(elevator_t *e)
481{ 380{
482 struct deadline_data *dd = e->elevator_data; 381 struct deadline_data *dd = e->elevator_data;
@@ -542,7 +441,6 @@ deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
542 drq = mempool_alloc(dd->drq_pool, gfp_mask); 441 drq = mempool_alloc(dd->drq_pool, gfp_mask);
543 if (drq) { 442 if (drq) {
544 memset(drq, 0, sizeof(*drq)); 443 memset(drq, 0, sizeof(*drq));
545 RB_CLEAR_NODE(&drq->rb_node);
546 drq->request = rq; 444 drq->request = rq;
547 445
548 INIT_LIST_HEAD(&drq->fifo); 446 INIT_LIST_HEAD(&drq->fifo);
@@ -633,8 +531,8 @@ static struct elevator_type iosched_deadline = {
633 .elevator_dispatch_fn = deadline_dispatch_requests, 531 .elevator_dispatch_fn = deadline_dispatch_requests,
634 .elevator_add_req_fn = deadline_add_request, 532 .elevator_add_req_fn = deadline_add_request,
635 .elevator_queue_empty_fn = deadline_queue_empty, 533 .elevator_queue_empty_fn = deadline_queue_empty,
636 .elevator_former_req_fn = deadline_former_request, 534 .elevator_former_req_fn = elv_rb_former_request,
637 .elevator_latter_req_fn = deadline_latter_request, 535 .elevator_latter_req_fn = elv_rb_latter_request,
638 .elevator_set_req_fn = deadline_set_request, 536 .elevator_set_req_fn = deadline_set_request,
639 .elevator_put_req_fn = deadline_put_request, 537 .elevator_put_req_fn = deadline_put_request,
640 .elevator_init_fn = deadline_init_queue, 538 .elevator_init_fn = deadline_init_queue,