Shaohua Li 474b18ccc2 cfq-iosched: no dispatch limit for single queue ...

Since commit 2f5cb7381b737e24c8046fd4aeab571fb71315f5, each queue can send
up to 4 * 4 requests if only one queue exists. I wonder why we have such limit.
Device supports tag can send more requests. For example, AHCI can send 31
requests. Test (direct aio randread) shows the limits reduce about 4% disk
thoughput.
On the other hand, since we send one request one time, if other queue
pop when current is sending more than cfq_quantum requests, current queue will
stop send requests soon after one request, so sounds there is no big latency.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2009-12-03 12:58:05 +01:00

..

blk-barrier.c

block: allow large discard requests

2009-10-01 21:19:34 +02:00

blk-core.c

block: add helpers to run flush_dcache_page() against a bio and a request's pages

2009-11-26 09:16:19 +01:00

blk-exec.c

block: don't set REQ_NOMERGE unnecessarily

2009-04-28 07:37:33 +02:00

blk-integrity.c

block: fix improper kobject release in blk_integrity_unregister

2009-07-28 09:11:14 +02:00

blk-ioc.c

block: prevent possible io_context->refcount overflow

2009-06-10 23:07:15 +02:00

blk-iopoll.c

block: use interrupts disabled version of raise_softirq_irqoff()

2009-09-11 14:33:32 +02:00

blk-map.c

block: Use accessor functions for queue limits

2009-05-22 23:22:54 +02:00

blk-merge.c

block: Seperate read and write statistics of in_flight requests v2

2009-10-06 20:16:55 +02:00

blk-settings.c

block: Allow devices to indicate whether discarded blocks are zeroed

2009-12-03 09:24:48 +01:00

blk-softirq.c

generic-ipi: remove CSD_FLAG_WAIT

2009-02-25 14:13:44 +01:00

blk-sysfs.c

block: Allow devices to indicate whether discarded blocks are zeroed

2009-12-03 09:24:48 +01:00

blk-tag.c

block: use proper BLK_RW_ASYNC in blk_queue_start_tag()

2009-10-06 20:19:02 +02:00

blk-timeout.c

block: clean up misc stuff after block layer timeout conversion

2009-04-28 07:37:34 +02:00

blk.h

block: implement mixed merge of different failfast requests

2009-09-11 14:33:30 +02:00

bsg.c

block: jiffies fixes

2009-11-11 13:47:45 +01:00

cfq-iosched.c

cfq-iosched: no dispatch limit for single queue

2009-12-03 12:58:05 +01:00

compat_ioctl.c

block: Allow devices to indicate whether discarded blocks are zeroed

2009-12-03 09:24:48 +01:00

deadline-iosched.c

block: convert to pos and nr_sectors accessors

2009-05-11 09:50:54 +02:00

elevator.c

Merge branch 'for-linus' into for-2.6.33

2009-10-13 12:29:45 +02:00

genhd.c

block: Expose discard granularity

2009-11-10 11:50:21 +01:00

ioctl.c

block: Allow devices to indicate whether discarded blocks are zeroed

2009-12-03 09:24:48 +01:00

Kconfig

Make SCSI SG v4 driver enabled by default and remove EXPERIMENTAL dependency, since udev depends on BSG

2009-08-04 22:10:17 +02:00

Kconfig.iosched

block: CFQ is more than a desktop scheduler

2009-10-03 09:40:47 +02:00

Makefile

block: remove the anticipatory IO scheduler

2009-10-03 09:37:51 +02:00

noop-iosched.c

block: get rid of elevator_t typedef

2008-12-29 08:29:50 +01:00

scsi_ioctl.c

block/scsi_ioctl.c: quiet sparse noise

2009-11-04 09:10:33 +01:00