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authorLinus Torvalds <torvalds@linux-foundation.org>2008-10-10 13:52:45 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-10 13:52:45 -0400
commite26feff647ef34423b048b940540a0059001ddb0 (patch)
treeacafe68602ee2f6f1a438c113073ffcc0040e949 /block/cfq-iosched.c
parentd403a6484f0341bf0624d17ece46f24f741b6a92 (diff)
parentb911e473d24633c19414b54b82b9ff0b1a2419d7 (diff)
Merge branch 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block: (132 commits) doc/cdrom: Trvial documentation error, file not present block_dev: fix kernel-doc in new functions block: add some comments around the bio read-write flags block: mark bio_split_pool static block: Find bio sector offset given idx and offset block: gendisk integrity wrapper block: Switch blk_integrity_compare from bdev to gendisk block: Fix double put in blk_integrity_unregister block: Introduce integrity data ownership flag block: revert part of d7533ad0e132f92e75c1b2eb7c26387b25a583c1 bio.h: Remove unused conditional code block: remove end_{queued|dequeued}_request() block: change elevator to use __blk_end_request() gdrom: change to use __blk_end_request() memstick: change to use __blk_end_request() virtio_blk: change to use __blk_end_request() blktrace: use BLKTRACE_BDEV_SIZE as the name size for setup structure block: add lld busy state exporting interface block: Fix blk_start_queueing() to not kick a stopped queue include blktrace_api.h in headers_install ...
Diffstat (limited to 'block/cfq-iosched.c')
-rw-r--r--block/cfq-iosched.c57
1 files changed, 47 insertions, 10 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 1e2aff812ee2..6a062eebbd15 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -39,6 +39,7 @@ static int cfq_slice_idle = HZ / 125;
39#define CFQ_MIN_TT (2) 39#define CFQ_MIN_TT (2)
40 40
41#define CFQ_SLICE_SCALE (5) 41#define CFQ_SLICE_SCALE (5)
42#define CFQ_HW_QUEUE_MIN (5)
42 43
43#define RQ_CIC(rq) \ 44#define RQ_CIC(rq) \
44 ((struct cfq_io_context *) (rq)->elevator_private) 45 ((struct cfq_io_context *) (rq)->elevator_private)
@@ -86,7 +87,14 @@ struct cfq_data {
86 87
87 int rq_in_driver; 88 int rq_in_driver;
88 int sync_flight; 89 int sync_flight;
90
91 /*
92 * queue-depth detection
93 */
94 int rq_queued;
89 int hw_tag; 95 int hw_tag;
96 int hw_tag_samples;
97 int rq_in_driver_peak;
90 98
91 /* 99 /*
92 * idle window management 100 * idle window management
@@ -244,7 +252,7 @@ static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
244{ 252{
245 if (cfqd->busy_queues) { 253 if (cfqd->busy_queues) {
246 cfq_log(cfqd, "schedule dispatch"); 254 cfq_log(cfqd, "schedule dispatch");
247 kblockd_schedule_work(&cfqd->unplug_work); 255 kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work);
248 } 256 }
249} 257}
250 258
@@ -654,15 +662,6 @@ static void cfq_activate_request(struct request_queue *q, struct request *rq)
654 cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", 662 cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d",
655 cfqd->rq_in_driver); 663 cfqd->rq_in_driver);
656 664
657 /*
658 * If the depth is larger 1, it really could be queueing. But lets
659 * make the mark a little higher - idling could still be good for
660 * low queueing, and a low queueing number could also just indicate
661 * a SCSI mid layer like behaviour where limit+1 is often seen.
662 */
663 if (!cfqd->hw_tag && cfqd->rq_in_driver > 4)
664 cfqd->hw_tag = 1;
665
666 cfqd->last_position = rq->hard_sector + rq->hard_nr_sectors; 665 cfqd->last_position = rq->hard_sector + rq->hard_nr_sectors;
667} 666}
668 667
@@ -686,6 +685,7 @@ static void cfq_remove_request(struct request *rq)
686 list_del_init(&rq->queuelist); 685 list_del_init(&rq->queuelist);
687 cfq_del_rq_rb(rq); 686 cfq_del_rq_rb(rq);
688 687
688 cfqq->cfqd->rq_queued--;
689 if (rq_is_meta(rq)) { 689 if (rq_is_meta(rq)) {
690 WARN_ON(!cfqq->meta_pending); 690 WARN_ON(!cfqq->meta_pending);
691 cfqq->meta_pending--; 691 cfqq->meta_pending--;
@@ -878,6 +878,14 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
878 struct cfq_io_context *cic; 878 struct cfq_io_context *cic;
879 unsigned long sl; 879 unsigned long sl;
880 880
881 /*
882 * SSD device without seek penalty, disable idling. But only do so
883 * for devices that support queuing, otherwise we still have a problem
884 * with sync vs async workloads.
885 */
886 if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)
887 return;
888
881 WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); 889 WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list));
882 WARN_ON(cfq_cfqq_slice_new(cfqq)); 890 WARN_ON(cfq_cfqq_slice_new(cfqq));
883 891
@@ -1833,6 +1841,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
1833{ 1841{
1834 struct cfq_io_context *cic = RQ_CIC(rq); 1842 struct cfq_io_context *cic = RQ_CIC(rq);
1835 1843
1844 cfqd->rq_queued++;
1836 if (rq_is_meta(rq)) 1845 if (rq_is_meta(rq))
1837 cfqq->meta_pending++; 1846 cfqq->meta_pending++;
1838 1847
@@ -1880,6 +1889,31 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq)
1880 cfq_rq_enqueued(cfqd, cfqq, rq); 1889 cfq_rq_enqueued(cfqd, cfqq, rq);
1881} 1890}
1882 1891
1892/*
1893 * Update hw_tag based on peak queue depth over 50 samples under
1894 * sufficient load.
1895 */
1896static void cfq_update_hw_tag(struct cfq_data *cfqd)
1897{
1898 if (cfqd->rq_in_driver > cfqd->rq_in_driver_peak)
1899 cfqd->rq_in_driver_peak = cfqd->rq_in_driver;
1900
1901 if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN &&
1902 cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN)
1903 return;
1904
1905 if (cfqd->hw_tag_samples++ < 50)
1906 return;
1907
1908 if (cfqd->rq_in_driver_peak >= CFQ_HW_QUEUE_MIN)
1909 cfqd->hw_tag = 1;
1910 else
1911 cfqd->hw_tag = 0;
1912
1913 cfqd->hw_tag_samples = 0;
1914 cfqd->rq_in_driver_peak = 0;
1915}
1916
1883static void cfq_completed_request(struct request_queue *q, struct request *rq) 1917static void cfq_completed_request(struct request_queue *q, struct request *rq)
1884{ 1918{
1885 struct cfq_queue *cfqq = RQ_CFQQ(rq); 1919 struct cfq_queue *cfqq = RQ_CFQQ(rq);
@@ -1890,6 +1924,8 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
1890 now = jiffies; 1924 now = jiffies;
1891 cfq_log_cfqq(cfqd, cfqq, "complete"); 1925 cfq_log_cfqq(cfqd, cfqq, "complete");
1892 1926
1927 cfq_update_hw_tag(cfqd);
1928
1893 WARN_ON(!cfqd->rq_in_driver); 1929 WARN_ON(!cfqd->rq_in_driver);
1894 WARN_ON(!cfqq->dispatched); 1930 WARN_ON(!cfqq->dispatched);
1895 cfqd->rq_in_driver--; 1931 cfqd->rq_in_driver--;
@@ -2200,6 +2236,7 @@ static void *cfq_init_queue(struct request_queue *q)
2200 cfqd->cfq_slice[1] = cfq_slice_sync; 2236 cfqd->cfq_slice[1] = cfq_slice_sync;
2201 cfqd->cfq_slice_async_rq = cfq_slice_async_rq; 2237 cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
2202 cfqd->cfq_slice_idle = cfq_slice_idle; 2238 cfqd->cfq_slice_idle = cfq_slice_idle;
2239 cfqd->hw_tag = 1;
2203 2240
2204 return cfqd; 2241 return cfqd;
2205} 2242}
generated by cgit v1.2.2 (git 2.25.0) at 2025-06-03 04:04:54 -0400