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-rw-r--r--drivers/block/cfq-iosched.c394
1 files changed, 86 insertions, 308 deletions
diff --git a/drivers/block/cfq-iosched.c b/drivers/block/cfq-iosched.c
index cd056e7e64ec..5281f8e70510 100644
--- a/drivers/block/cfq-iosched.c
+++ b/drivers/block/cfq-iosched.c
@@ -84,7 +84,6 @@ static int cfq_max_depth = 2;
84 (node)->rb_left = NULL; \ 84 (node)->rb_left = NULL; \
85} while (0) 85} while (0)
86#define RB_CLEAR_ROOT(root) ((root)->rb_node = NULL) 86#define RB_CLEAR_ROOT(root) ((root)->rb_node = NULL)
87#define ON_RB(node) ((node)->rb_color != RB_NONE)
88#define rb_entry_crq(node) rb_entry((node), struct cfq_rq, rb_node) 87#define rb_entry_crq(node) rb_entry((node), struct cfq_rq, rb_node)
89#define rq_rb_key(rq) (rq)->sector 88#define rq_rb_key(rq) (rq)->sector
90 89
@@ -271,10 +270,7 @@ CFQ_CFQQ_FNS(expired);
271#undef CFQ_CFQQ_FNS 270#undef CFQ_CFQQ_FNS
272 271
273enum cfq_rq_state_flags { 272enum cfq_rq_state_flags {
274 CFQ_CRQ_FLAG_in_flight = 0, 273 CFQ_CRQ_FLAG_is_sync = 0,
275 CFQ_CRQ_FLAG_in_driver,
276 CFQ_CRQ_FLAG_is_sync,
277 CFQ_CRQ_FLAG_requeued,
278}; 274};
279 275
280#define CFQ_CRQ_FNS(name) \ 276#define CFQ_CRQ_FNS(name) \
@@ -291,14 +287,11 @@ static inline int cfq_crq_##name(const struct cfq_rq *crq) \
291 return (crq->crq_flags & (1 << CFQ_CRQ_FLAG_##name)) != 0; \ 287 return (crq->crq_flags & (1 << CFQ_CRQ_FLAG_##name)) != 0; \
292} 288}
293 289
294CFQ_CRQ_FNS(in_flight);
295CFQ_CRQ_FNS(in_driver);
296CFQ_CRQ_FNS(is_sync); 290CFQ_CRQ_FNS(is_sync);
297CFQ_CRQ_FNS(requeued);
298#undef CFQ_CRQ_FNS 291#undef CFQ_CRQ_FNS
299 292
300static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsigned short); 293static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsigned short);
301static void cfq_dispatch_sort(request_queue_t *, struct cfq_rq *); 294static void cfq_dispatch_insert(request_queue_t *, struct cfq_rq *);
302static void cfq_put_cfqd(struct cfq_data *cfqd); 295static void cfq_put_cfqd(struct cfq_data *cfqd);
303 296
304#define process_sync(tsk) ((tsk)->flags & PF_SYNCWRITE) 297#define process_sync(tsk) ((tsk)->flags & PF_SYNCWRITE)
@@ -311,14 +304,6 @@ static inline void cfq_del_crq_hash(struct cfq_rq *crq)
311 hlist_del_init(&crq->hash); 304 hlist_del_init(&crq->hash);
312} 305}
313 306
314static void cfq_remove_merge_hints(request_queue_t *q, struct cfq_rq *crq)
315{
316 cfq_del_crq_hash(crq);
317
318 if (q->last_merge == crq->request)
319 q->last_merge = NULL;
320}
321
322static inline void cfq_add_crq_hash(struct cfq_data *cfqd, struct cfq_rq *crq) 307static inline void cfq_add_crq_hash(struct cfq_data *cfqd, struct cfq_rq *crq)
323{ 308{
324 const int hash_idx = CFQ_MHASH_FN(rq_hash_key(crq->request)); 309 const int hash_idx = CFQ_MHASH_FN(rq_hash_key(crq->request));
@@ -347,18 +332,13 @@ static struct request *cfq_find_rq_hash(struct cfq_data *cfqd, sector_t offset)
347 return NULL; 332 return NULL;
348} 333}
349 334
350static inline int cfq_pending_requests(struct cfq_data *cfqd)
351{
352 return !list_empty(&cfqd->queue->queue_head) || cfqd->busy_queues;
353}
354
355/* 335/*
356 * scheduler run of queue, if there are requests pending and no one in the 336 * scheduler run of queue, if there are requests pending and no one in the
357 * driver that will restart queueing 337 * driver that will restart queueing
358 */ 338 */
359static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) 339static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
360{ 340{
361 if (!cfqd->rq_in_driver && cfq_pending_requests(cfqd)) 341 if (!cfqd->rq_in_driver && cfqd->busy_queues)
362 kblockd_schedule_work(&cfqd->unplug_work); 342 kblockd_schedule_work(&cfqd->unplug_work);
363} 343}
364 344
@@ -366,7 +346,7 @@ static int cfq_queue_empty(request_queue_t *q)
366{ 346{
367 struct cfq_data *cfqd = q->elevator->elevator_data; 347 struct cfq_data *cfqd = q->elevator->elevator_data;
368 348
369 return !cfq_pending_requests(cfqd); 349 return !cfqd->busy_queues;
370} 350}
371 351
372/* 352/*
@@ -386,11 +366,6 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2)
386 if (crq2 == NULL) 366 if (crq2 == NULL)
387 return crq1; 367 return crq1;
388 368
389 if (cfq_crq_requeued(crq1) && !cfq_crq_requeued(crq2))
390 return crq1;
391 else if (cfq_crq_requeued(crq2) && !cfq_crq_requeued(crq1))
392 return crq2;
393
394 if (cfq_crq_is_sync(crq1) && !cfq_crq_is_sync(crq2)) 369 if (cfq_crq_is_sync(crq1) && !cfq_crq_is_sync(crq2))
395 return crq1; 370 return crq1;
396 else if (cfq_crq_is_sync(crq2) && !cfq_crq_is_sync(crq1)) 371 else if (cfq_crq_is_sync(crq2) && !cfq_crq_is_sync(crq1))
@@ -461,10 +436,7 @@ cfq_find_next_crq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
461 struct cfq_rq *crq_next = NULL, *crq_prev = NULL; 436 struct cfq_rq *crq_next = NULL, *crq_prev = NULL;
462 struct rb_node *rbnext, *rbprev; 437 struct rb_node *rbnext, *rbprev;
463 438
464 rbnext = NULL; 439 if (!(rbnext = rb_next(&last->rb_node))) {
465 if (ON_RB(&last->rb_node))
466 rbnext = rb_next(&last->rb_node);
467 if (!rbnext) {
468 rbnext = rb_first(&cfqq->sort_list); 440 rbnext = rb_first(&cfqq->sort_list);
469 if (rbnext == &last->rb_node) 441 if (rbnext == &last->rb_node)
470 rbnext = NULL; 442 rbnext = NULL;
@@ -545,13 +517,13 @@ static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted)
545 * the pending list according to last request service 517 * the pending list according to last request service
546 */ 518 */
547static inline void 519static inline void
548cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq, int requeue) 520cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
549{ 521{
550 BUG_ON(cfq_cfqq_on_rr(cfqq)); 522 BUG_ON(cfq_cfqq_on_rr(cfqq));
551 cfq_mark_cfqq_on_rr(cfqq); 523 cfq_mark_cfqq_on_rr(cfqq);
552 cfqd->busy_queues++; 524 cfqd->busy_queues++;
553 525
554 cfq_resort_rr_list(cfqq, requeue); 526 cfq_resort_rr_list(cfqq, 0);
555} 527}
556 528
557static inline void 529static inline void
@@ -571,22 +543,19 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
571static inline void cfq_del_crq_rb(struct cfq_rq *crq) 543static inline void cfq_del_crq_rb(struct cfq_rq *crq)
572{ 544{
573 struct cfq_queue *cfqq = crq->cfq_queue; 545 struct cfq_queue *cfqq = crq->cfq_queue;
546 struct cfq_data *cfqd = cfqq->cfqd;
547 const int sync = cfq_crq_is_sync(crq);
574 548
575 if (ON_RB(&crq->rb_node)) { 549 BUG_ON(!cfqq->queued[sync]);
576 struct cfq_data *cfqd = cfqq->cfqd; 550 cfqq->queued[sync]--;
577 const int sync = cfq_crq_is_sync(crq);
578
579 BUG_ON(!cfqq->queued[sync]);
580 cfqq->queued[sync]--;
581 551
582 cfq_update_next_crq(crq); 552 cfq_update_next_crq(crq);
583 553
584 rb_erase(&crq->rb_node, &cfqq->sort_list); 554 rb_erase(&crq->rb_node, &cfqq->sort_list);
585 RB_CLEAR_COLOR(&crq->rb_node); 555 RB_CLEAR_COLOR(&crq->rb_node);
586 556
587 if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY(&cfqq->sort_list)) 557 if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY(&cfqq->sort_list))
588 cfq_del_cfqq_rr(cfqd, cfqq); 558 cfq_del_cfqq_rr(cfqd, cfqq);
589 }
590} 559}
591 560
592static struct cfq_rq * 561static struct cfq_rq *
@@ -627,12 +596,12 @@ static void cfq_add_crq_rb(struct cfq_rq *crq)
627 * if that happens, put the alias on the dispatch list 596 * if that happens, put the alias on the dispatch list
628 */ 597 */
629 while ((__alias = __cfq_add_crq_rb(crq)) != NULL) 598 while ((__alias = __cfq_add_crq_rb(crq)) != NULL)
630 cfq_dispatch_sort(cfqd->queue, __alias); 599 cfq_dispatch_insert(cfqd->queue, __alias);
631 600
632 rb_insert_color(&crq->rb_node, &cfqq->sort_list); 601 rb_insert_color(&crq->rb_node, &cfqq->sort_list);
633 602
634 if (!cfq_cfqq_on_rr(cfqq)) 603 if (!cfq_cfqq_on_rr(cfqq))
635 cfq_add_cfqq_rr(cfqd, cfqq, cfq_crq_requeued(crq)); 604 cfq_add_cfqq_rr(cfqd, cfqq);
636 605
637 /* 606 /*
638 * check if this request is a better next-serve candidate 607 * check if this request is a better next-serve candidate
@@ -643,10 +612,8 @@ static void cfq_add_crq_rb(struct cfq_rq *crq)
643static inline void 612static inline void
644cfq_reposition_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq) 613cfq_reposition_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
645{ 614{
646 if (ON_RB(&crq->rb_node)) { 615 rb_erase(&crq->rb_node, &cfqq->sort_list);
647 rb_erase(&crq->rb_node, &cfqq->sort_list); 616 cfqq->queued[cfq_crq_is_sync(crq)]--;
648 cfqq->queued[cfq_crq_is_sync(crq)]--;
649 }
650 617
651 cfq_add_crq_rb(crq); 618 cfq_add_crq_rb(crq);
652} 619}
@@ -676,49 +643,28 @@ out:
676 return NULL; 643 return NULL;
677} 644}
678 645
679static void cfq_deactivate_request(request_queue_t *q, struct request *rq) 646static void cfq_activate_request(request_queue_t *q, struct request *rq)
680{ 647{
681 struct cfq_data *cfqd = q->elevator->elevator_data; 648 struct cfq_data *cfqd = q->elevator->elevator_data;
682 struct cfq_rq *crq = RQ_DATA(rq);
683
684 if (crq) {
685 struct cfq_queue *cfqq = crq->cfq_queue;
686 649
687 if (cfq_crq_in_driver(crq)) { 650 cfqd->rq_in_driver++;
688 cfq_clear_crq_in_driver(crq);
689 WARN_ON(!cfqd->rq_in_driver);
690 cfqd->rq_in_driver--;
691 }
692 if (cfq_crq_in_flight(crq)) {
693 const int sync = cfq_crq_is_sync(crq);
694
695 cfq_clear_crq_in_flight(crq);
696 WARN_ON(!cfqq->on_dispatch[sync]);
697 cfqq->on_dispatch[sync]--;
698 }
699 cfq_mark_crq_requeued(crq);
700 }
701} 651}
702 652
703/* 653static void cfq_deactivate_request(request_queue_t *q, struct request *rq)
704 * make sure the service time gets corrected on reissue of this request
705 */
706static void cfq_requeue_request(request_queue_t *q, struct request *rq)
707{ 654{
708 cfq_deactivate_request(q, rq); 655 struct cfq_data *cfqd = q->elevator->elevator_data;
709 list_add(&rq->queuelist, &q->queue_head); 656
657 WARN_ON(!cfqd->rq_in_driver);
658 cfqd->rq_in_driver--;
710} 659}
711 660
712static void cfq_remove_request(request_queue_t *q, struct request *rq) 661static void cfq_remove_request(struct request *rq)
713{ 662{
714 struct cfq_rq *crq = RQ_DATA(rq); 663 struct cfq_rq *crq = RQ_DATA(rq);
715 664
716 if (crq) { 665 list_del_init(&rq->queuelist);
717 list_del_init(&rq->queuelist); 666 cfq_del_crq_rb(crq);
718 cfq_del_crq_rb(crq); 667 cfq_del_crq_hash(crq);
719 cfq_remove_merge_hints(q, crq);
720
721 }
722} 668}
723 669
724static int 670static int
@@ -728,12 +674,6 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio)
728 struct request *__rq; 674 struct request *__rq;
729 int ret; 675 int ret;
730 676
731 ret = elv_try_last_merge(q, bio);
732 if (ret != ELEVATOR_NO_MERGE) {
733 __rq = q->last_merge;
734 goto out_insert;
735 }
736
737 __rq = cfq_find_rq_hash(cfqd, bio->bi_sector); 677 __rq = cfq_find_rq_hash(cfqd, bio->bi_sector);
738 if (__rq && elv_rq_merge_ok(__rq, bio)) { 678 if (__rq && elv_rq_merge_ok(__rq, bio)) {
739 ret = ELEVATOR_BACK_MERGE; 679 ret = ELEVATOR_BACK_MERGE;
@@ -748,8 +688,6 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio)
748 688
749 return ELEVATOR_NO_MERGE; 689 return ELEVATOR_NO_MERGE;
750out: 690out:
751 q->last_merge = __rq;
752out_insert:
753 *req = __rq; 691 *req = __rq;
754 return ret; 692 return ret;
755} 693}
@@ -762,14 +700,12 @@ static void cfq_merged_request(request_queue_t *q, struct request *req)
762 cfq_del_crq_hash(crq); 700 cfq_del_crq_hash(crq);
763 cfq_add_crq_hash(cfqd, crq); 701 cfq_add_crq_hash(cfqd, crq);
764 702
765 if (ON_RB(&crq->rb_node) && (rq_rb_key(req) != crq->rb_key)) { 703 if (rq_rb_key(req) != crq->rb_key) {
766 struct cfq_queue *cfqq = crq->cfq_queue; 704 struct cfq_queue *cfqq = crq->cfq_queue;
767 705
768 cfq_update_next_crq(crq); 706 cfq_update_next_crq(crq);
769 cfq_reposition_crq_rb(cfqq, crq); 707 cfq_reposition_crq_rb(cfqq, crq);
770 } 708 }
771
772 q->last_merge = req;
773} 709}
774 710
775static void 711static void
@@ -785,7 +721,7 @@ cfq_merged_requests(request_queue_t *q, struct request *rq,
785 time_before(next->start_time, rq->start_time)) 721 time_before(next->start_time, rq->start_time))
786 list_move(&rq->queuelist, &next->queuelist); 722 list_move(&rq->queuelist, &next->queuelist);
787 723
788 cfq_remove_request(q, next); 724 cfq_remove_request(next);
789} 725}
790 726
791static inline void 727static inline void
@@ -992,53 +928,15 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
992 return 1; 928 return 1;
993} 929}
994 930
995/* 931static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq)
996 * we dispatch cfqd->cfq_quantum requests in total from the rr_list queues,
997 * this function sector sorts the selected request to minimize seeks. we start
998 * at cfqd->last_sector, not 0.
999 */
1000static void cfq_dispatch_sort(request_queue_t *q, struct cfq_rq *crq)
1001{ 932{
1002 struct cfq_data *cfqd = q->elevator->elevator_data; 933 struct cfq_data *cfqd = q->elevator->elevator_data;
1003 struct cfq_queue *cfqq = crq->cfq_queue; 934 struct cfq_queue *cfqq = crq->cfq_queue;
1004 struct list_head *head = &q->queue_head, *entry = head;
1005 struct request *__rq;
1006 sector_t last;
1007
1008 list_del(&crq->request->queuelist);
1009
1010 last = cfqd->last_sector;
1011 list_for_each_entry_reverse(__rq, head, queuelist) {
1012 struct cfq_rq *__crq = RQ_DATA(__rq);
1013
1014 if (blk_barrier_rq(__rq))
1015 break;
1016 if (!blk_fs_request(__rq))
1017 break;
1018 if (cfq_crq_requeued(__crq))
1019 break;
1020
1021 if (__rq->sector <= crq->request->sector)
1022 break;
1023 if (__rq->sector > last && crq->request->sector < last) {
1024 last = crq->request->sector + crq->request->nr_sectors;
1025 break;
1026 }
1027 entry = &__rq->queuelist;
1028 }
1029
1030 cfqd->last_sector = last;
1031 935
1032 cfqq->next_crq = cfq_find_next_crq(cfqd, cfqq, crq); 936 cfqq->next_crq = cfq_find_next_crq(cfqd, cfqq, crq);
1033 937 cfq_remove_request(crq->request);
1034 cfq_del_crq_rb(crq);
1035 cfq_remove_merge_hints(q, crq);
1036
1037 cfq_mark_crq_in_flight(crq);
1038 cfq_clear_crq_requeued(crq);
1039
1040 cfqq->on_dispatch[cfq_crq_is_sync(crq)]++; 938 cfqq->on_dispatch[cfq_crq_is_sync(crq)]++;
1041 list_add_tail(&crq->request->queuelist, entry); 939 elv_dispatch_sort(q, crq->request);
1042} 940}
1043 941
1044/* 942/*
@@ -1159,7 +1057,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
1159 /* 1057 /*
1160 * finally, insert request into driver dispatch list 1058 * finally, insert request into driver dispatch list
1161 */ 1059 */
1162 cfq_dispatch_sort(cfqd->queue, crq); 1060 cfq_dispatch_insert(cfqd->queue, crq);
1163 1061
1164 cfqd->dispatch_slice++; 1062 cfqd->dispatch_slice++;
1165 dispatched++; 1063 dispatched++;
@@ -1194,7 +1092,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
1194} 1092}
1195 1093
1196static int 1094static int
1197cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force) 1095cfq_dispatch_requests(request_queue_t *q, int force)
1198{ 1096{
1199 struct cfq_data *cfqd = q->elevator->elevator_data; 1097 struct cfq_data *cfqd = q->elevator->elevator_data;
1200 struct cfq_queue *cfqq; 1098 struct cfq_queue *cfqq;
@@ -1204,12 +1102,25 @@ cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force)
1204 1102
1205 cfqq = cfq_select_queue(cfqd, force); 1103 cfqq = cfq_select_queue(cfqd, force);
1206 if (cfqq) { 1104 if (cfqq) {
1105 int max_dispatch;
1106
1107 /*
1108 * if idle window is disabled, allow queue buildup
1109 */
1110 if (!cfq_cfqq_idle_window(cfqq) &&
1111 cfqd->rq_in_driver >= cfqd->cfq_max_depth)
1112 return 0;
1113
1207 cfq_clear_cfqq_must_dispatch(cfqq); 1114 cfq_clear_cfqq_must_dispatch(cfqq);
1208 cfq_clear_cfqq_wait_request(cfqq); 1115 cfq_clear_cfqq_wait_request(cfqq);
1209 del_timer(&cfqd->idle_slice_timer); 1116 del_timer(&cfqd->idle_slice_timer);
1210 1117
1211 if (cfq_class_idle(cfqq)) 1118 if (!force) {
1212 max_dispatch = 1; 1119 max_dispatch = cfqd->cfq_quantum;
1120 if (cfq_class_idle(cfqq))
1121 max_dispatch = 1;
1122 } else
1123 max_dispatch = INT_MAX;
1213 1124
1214 return __cfq_dispatch_requests(cfqd, cfqq, max_dispatch); 1125 return __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
1215 } 1126 }
@@ -1217,93 +1128,6 @@ cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force)
1217 return 0; 1128 return 0;
1218} 1129}
1219 1130
1220static inline void cfq_account_dispatch(struct cfq_rq *crq)
1221{
1222 struct cfq_queue *cfqq = crq->cfq_queue;
1223 struct cfq_data *cfqd = cfqq->cfqd;
1224
1225 if (unlikely(!blk_fs_request(crq->request)))
1226 return;
1227
1228 /*
1229 * accounted bit is necessary since some drivers will call
1230 * elv_next_request() many times for the same request (eg ide)
1231 */
1232 if (cfq_crq_in_driver(crq))
1233 return;
1234
1235 cfq_mark_crq_in_driver(crq);
1236 cfqd->rq_in_driver++;
1237}
1238
1239static inline void
1240cfq_account_completion(struct cfq_queue *cfqq, struct cfq_rq *crq)
1241{
1242 struct cfq_data *cfqd = cfqq->cfqd;
1243 unsigned long now;
1244
1245 if (!cfq_crq_in_driver(crq))
1246 return;
1247
1248 now = jiffies;
1249
1250 WARN_ON(!cfqd->rq_in_driver);
1251 cfqd->rq_in_driver--;
1252
1253 if (!cfq_class_idle(cfqq))
1254 cfqd->last_end_request = now;
1255
1256 if (!cfq_cfqq_dispatched(cfqq)) {
1257 if (cfq_cfqq_on_rr(cfqq)) {
1258 cfqq->service_last = now;
1259 cfq_resort_rr_list(cfqq, 0);
1260 }
1261 if (cfq_cfqq_expired(cfqq)) {
1262 __cfq_slice_expired(cfqd, cfqq, 0);
1263 cfq_schedule_dispatch(cfqd);
1264 }
1265 }
1266
1267 if (cfq_crq_is_sync(crq))
1268 crq->io_context->last_end_request = now;
1269}
1270
1271static struct request *cfq_next_request(request_queue_t *q)
1272{
1273 struct cfq_data *cfqd = q->elevator->elevator_data;
1274 struct request *rq;
1275
1276 if (!list_empty(&q->queue_head)) {
1277 struct cfq_rq *crq;
1278dispatch:
1279 rq = list_entry_rq(q->queue_head.next);
1280
1281 crq = RQ_DATA(rq);
1282 if (crq) {
1283 struct cfq_queue *cfqq = crq->cfq_queue;
1284
1285 /*
1286 * if idle window is disabled, allow queue buildup
1287 */
1288 if (!cfq_crq_in_driver(crq) &&
1289 !cfq_cfqq_idle_window(cfqq) &&
1290 !blk_barrier_rq(rq) &&
1291 cfqd->rq_in_driver >= cfqd->cfq_max_depth)
1292 return NULL;
1293
1294 cfq_remove_merge_hints(q, crq);
1295 cfq_account_dispatch(crq);
1296 }
1297
1298 return rq;
1299 }
1300
1301 if (cfq_dispatch_requests(q, cfqd->cfq_quantum, 0))
1302 goto dispatch;
1303
1304 return NULL;
1305}
1306
1307/* 1131/*
1308 * task holds one reference to the queue, dropped when task exits. each crq 1132 * task holds one reference to the queue, dropped when task exits. each crq
1309 * in-flight on this queue also holds a reference, dropped when crq is freed. 1133 * in-flight on this queue also holds a reference, dropped when crq is freed.
@@ -1422,7 +1246,7 @@ static void cfq_exit_io_context(struct cfq_io_context *cic)
1422} 1246}
1423 1247
1424static struct cfq_io_context * 1248static struct cfq_io_context *
1425cfq_alloc_io_context(struct cfq_data *cfqd, int gfp_mask) 1249cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
1426{ 1250{
1427 struct cfq_io_context *cic = kmem_cache_alloc(cfq_ioc_pool, gfp_mask); 1251 struct cfq_io_context *cic = kmem_cache_alloc(cfq_ioc_pool, gfp_mask);
1428 1252
@@ -1517,7 +1341,7 @@ static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio)
1517 1341
1518static struct cfq_queue * 1342static struct cfq_queue *
1519cfq_get_queue(struct cfq_data *cfqd, unsigned int key, unsigned short ioprio, 1343cfq_get_queue(struct cfq_data *cfqd, unsigned int key, unsigned short ioprio,
1520 int gfp_mask) 1344 gfp_t gfp_mask)
1521{ 1345{
1522 const int hashval = hash_long(key, CFQ_QHASH_SHIFT); 1346 const int hashval = hash_long(key, CFQ_QHASH_SHIFT);
1523 struct cfq_queue *cfqq, *new_cfqq = NULL; 1347 struct cfq_queue *cfqq, *new_cfqq = NULL;
@@ -1578,7 +1402,7 @@ out:
1578 * cfqq, so we don't need to worry about it disappearing 1402 * cfqq, so we don't need to worry about it disappearing
1579 */ 1403 */
1580static struct cfq_io_context * 1404static struct cfq_io_context *
1581cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, int gfp_mask) 1405cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask)
1582{ 1406{
1583 struct io_context *ioc = NULL; 1407 struct io_context *ioc = NULL;
1584 struct cfq_io_context *cic; 1408 struct cfq_io_context *cic;
@@ -1816,8 +1640,9 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
1816 } 1640 }
1817} 1641}
1818 1642
1819static void cfq_enqueue(struct cfq_data *cfqd, struct request *rq) 1643static void cfq_insert_request(request_queue_t *q, struct request *rq)
1820{ 1644{
1645 struct cfq_data *cfqd = q->elevator->elevator_data;
1821 struct cfq_rq *crq = RQ_DATA(rq); 1646 struct cfq_rq *crq = RQ_DATA(rq);
1822 struct cfq_queue *cfqq = crq->cfq_queue; 1647 struct cfq_queue *cfqq = crq->cfq_queue;
1823 1648
@@ -1827,66 +1652,43 @@ static void cfq_enqueue(struct cfq_data *cfqd, struct request *rq)
1827 1652
1828 list_add_tail(&rq->queuelist, &cfqq->fifo); 1653 list_add_tail(&rq->queuelist, &cfqq->fifo);
1829 1654
1830 if (rq_mergeable(rq)) { 1655 if (rq_mergeable(rq))
1831 cfq_add_crq_hash(cfqd, crq); 1656 cfq_add_crq_hash(cfqd, crq);
1832 1657
1833 if (!cfqd->queue->last_merge)
1834 cfqd->queue->last_merge = rq;
1835 }
1836
1837 cfq_crq_enqueued(cfqd, cfqq, crq); 1658 cfq_crq_enqueued(cfqd, cfqq, crq);
1838} 1659}
1839 1660
1840static void
1841cfq_insert_request(request_queue_t *q, struct request *rq, int where)
1842{
1843 struct cfq_data *cfqd = q->elevator->elevator_data;
1844
1845 switch (where) {
1846 case ELEVATOR_INSERT_BACK:
1847 while (cfq_dispatch_requests(q, INT_MAX, 1))
1848 ;
1849 list_add_tail(&rq->queuelist, &q->queue_head);
1850 /*
1851 * If we were idling with pending requests on
1852 * inactive cfqqs, force dispatching will
1853 * remove the idle timer and the queue won't
1854 * be kicked by __make_request() afterward.
1855 * Kick it here.
1856 */
1857 cfq_schedule_dispatch(cfqd);
1858 break;
1859 case ELEVATOR_INSERT_FRONT:
1860 list_add(&rq->queuelist, &q->queue_head);
1861 break;
1862 case ELEVATOR_INSERT_SORT:
1863 BUG_ON(!blk_fs_request(rq));
1864 cfq_enqueue(cfqd, rq);
1865 break;
1866 default:
1867 printk("%s: bad insert point %d\n", __FUNCTION__,where);
1868 return;
1869 }
1870}
1871
1872static void cfq_completed_request(request_queue_t *q, struct request *rq) 1661static void cfq_completed_request(request_queue_t *q, struct request *rq)
1873{ 1662{
1874 struct cfq_rq *crq = RQ_DATA(rq); 1663 struct cfq_rq *crq = RQ_DATA(rq);
1875 struct cfq_queue *cfqq; 1664 struct cfq_queue *cfqq = crq->cfq_queue;
1665 struct cfq_data *cfqd = cfqq->cfqd;
1666 const int sync = cfq_crq_is_sync(crq);
1667 unsigned long now;
1876 1668
1877 if (unlikely(!blk_fs_request(rq))) 1669 now = jiffies;
1878 return;
1879 1670
1880 cfqq = crq->cfq_queue; 1671 WARN_ON(!cfqd->rq_in_driver);
1672 WARN_ON(!cfqq->on_dispatch[sync]);
1673 cfqd->rq_in_driver--;
1674 cfqq->on_dispatch[sync]--;
1881 1675
1882 if (cfq_crq_in_flight(crq)) { 1676 if (!cfq_class_idle(cfqq))
1883 const int sync = cfq_crq_is_sync(crq); 1677 cfqd->last_end_request = now;
1884 1678
1885 WARN_ON(!cfqq->on_dispatch[sync]); 1679 if (!cfq_cfqq_dispatched(cfqq)) {
1886 cfqq->on_dispatch[sync]--; 1680 if (cfq_cfqq_on_rr(cfqq)) {
1681 cfqq->service_last = now;
1682 cfq_resort_rr_list(cfqq, 0);
1683 }
1684 if (cfq_cfqq_expired(cfqq)) {
1685 __cfq_slice_expired(cfqd, cfqq, 0);
1686 cfq_schedule_dispatch(cfqd);
1687 }
1887 } 1688 }
1888 1689
1889 cfq_account_completion(cfqq, crq); 1690 if (cfq_crq_is_sync(crq))
1691 crq->io_context->last_end_request = now;
1890} 1692}
1891 1693
1892static struct request * 1694static struct request *
@@ -2075,7 +1877,7 @@ static void cfq_put_request(request_queue_t *q, struct request *rq)
2075 */ 1877 */
2076static int 1878static int
2077cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio, 1879cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
2078 int gfp_mask) 1880 gfp_t gfp_mask)
2079{ 1881{
2080 struct cfq_data *cfqd = q->elevator->elevator_data; 1882 struct cfq_data *cfqd = q->elevator->elevator_data;
2081 struct task_struct *tsk = current; 1883 struct task_struct *tsk = current;
@@ -2118,9 +1920,6 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
2118 INIT_HLIST_NODE(&crq->hash); 1920 INIT_HLIST_NODE(&crq->hash);
2119 crq->cfq_queue = cfqq; 1921 crq->cfq_queue = cfqq;
2120 crq->io_context = cic; 1922 crq->io_context = cic;
2121 cfq_clear_crq_in_flight(crq);
2122 cfq_clear_crq_in_driver(crq);
2123 cfq_clear_crq_requeued(crq);
2124 1923
2125 if (rw == READ || process_sync(tsk)) 1924 if (rw == READ || process_sync(tsk))
2126 cfq_mark_crq_is_sync(crq); 1925 cfq_mark_crq_is_sync(crq);
@@ -2201,7 +2000,7 @@ static void cfq_idle_slice_timer(unsigned long data)
2201 * only expire and reinvoke request handler, if there are 2000 * only expire and reinvoke request handler, if there are
2202 * other queues with pending requests 2001 * other queues with pending requests
2203 */ 2002 */
2204 if (!cfq_pending_requests(cfqd)) { 2003 if (!cfqd->busy_queues) {
2205 cfqd->idle_slice_timer.expires = min(now + cfqd->cfq_slice_idle, cfqq->slice_end); 2004 cfqd->idle_slice_timer.expires = min(now + cfqd->cfq_slice_idle, cfqq->slice_end);
2206 add_timer(&cfqd->idle_slice_timer); 2005 add_timer(&cfqd->idle_slice_timer);
2207 goto out_cont; 2006 goto out_cont;
@@ -2576,10 +2375,9 @@ static struct elevator_type iosched_cfq = {
2576 .elevator_merge_fn = cfq_merge, 2375 .elevator_merge_fn = cfq_merge,
2577 .elevator_merged_fn = cfq_merged_request, 2376 .elevator_merged_fn = cfq_merged_request,
2578 .elevator_merge_req_fn = cfq_merged_requests, 2377 .elevator_merge_req_fn = cfq_merged_requests,
2579 .elevator_next_req_fn = cfq_next_request, 2378 .elevator_dispatch_fn = cfq_dispatch_requests,
2580 .elevator_add_req_fn = cfq_insert_request, 2379 .elevator_add_req_fn = cfq_insert_request,
2581 .elevator_remove_req_fn = cfq_remove_request, 2380 .elevator_activate_req_fn = cfq_activate_request,
2582 .elevator_requeue_req_fn = cfq_requeue_request,
2583 .elevator_deactivate_req_fn = cfq_deactivate_request, 2381 .elevator_deactivate_req_fn = cfq_deactivate_request,
2584 .elevator_queue_empty_fn = cfq_queue_empty, 2382 .elevator_queue_empty_fn = cfq_queue_empty,
2585 .elevator_completed_req_fn = cfq_completed_request, 2383 .elevator_completed_req_fn = cfq_completed_request,
@@ -2620,28 +2418,8 @@ static int __init cfq_init(void)
2620 2418
2621static void __exit cfq_exit(void) 2419static void __exit cfq_exit(void)
2622{ 2420{
2623 struct task_struct *g, *p;
2624 unsigned long flags;
2625
2626 read_lock_irqsave(&tasklist_lock, flags);
2627
2628 /*
2629 * iterate each process in the system, removing our io_context
2630 */
2631 do_each_thread(g, p) {
2632 struct io_context *ioc = p->io_context;
2633
2634 if (ioc && ioc->cic) {
2635 ioc->cic->exit(ioc->cic);
2636 cfq_free_io_context(ioc->cic);
2637 ioc->cic = NULL;
2638 }
2639 } while_each_thread(g, p);
2640
2641 read_unlock_irqrestore(&tasklist_lock, flags);
2642
2643 cfq_slab_kill();
2644 elv_unregister(&iosched_cfq); 2421 elv_unregister(&iosched_cfq);
2422 cfq_slab_kill();
2645} 2423}
2646 2424
2647module_init(cfq_init); 2425module_init(cfq_init);