Aaron Carroll 45333d5a31 cfq-iosched: fix queue depth detection ...

CFQ's detection of queueing devices assumes a non-queuing device and detects
if the queue depth reaches a certain threshold.  Under some workloads (e.g.
synchronous reads), CFQ effectively forces a unit queue depth, thus defeating
the detection logic.  This leads to poor performance on queuing hardware,
since the idle window remains enabled.

This patch inverts the sense of the logic: assume a queuing-capable device,
and detect if the depth does not exceed the threshold.

Signed-off-by: Aaron Carroll <aaronc@gelato.unsw.edu.au>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2008-10-09 08:56:09 +02:00

..

as-iosched.c

block: make kblockd_schedule_work() take the queue as parameter

2008-10-09 08:56:09 +02:00

blk-barrier.c

Allow elevators to sort/merge discard requests

2008-10-09 08:56:02 +02:00

blk-core.c

block: don't use bio_has_data() in the completion path

2008-10-09 08:56:09 +02:00

blk-exec.c

Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC.

2008-10-09 08:56:03 +02:00

blk-integrity.c

block: implement and use {disk|part}_to_dev()

2008-10-09 08:56:07 +02:00

blk-ioc.c

cfq-iosched: fix RCU race in the cfq io_context destructor handling

2008-05-07 09:28:57 +02:00

blk-map.c

Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC.

2008-10-09 08:56:03 +02:00

blk-merge.c

block: inherit CPU completion on bio->rq and rq->rq merges

2008-10-09 08:56:09 +02:00

blk-settings.c

block: add support for IO CPU affinity

2008-10-09 08:56:09 +02:00

blk-softirq.c

block: add support for IO CPU affinity

2008-10-09 08:56:09 +02:00

blk-sysfs.c

block: add support for IO CPU affinity

2008-10-09 08:56:09 +02:00

blk-tag.c

Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC.

2008-10-09 08:56:03 +02:00

blk.h

block: add support for IO CPU affinity

2008-10-09 08:56:09 +02:00

blktrace.c

blktrace: simplify flags handling in __blk_add_trace

2008-10-09 08:56:01 +02:00

bsg.c

block: move cmdfilter from gendisk to request_queue

2008-08-27 09:50:19 +02:00

cfq-iosched.c

cfq-iosched: fix queue depth detection

2008-10-09 08:56:09 +02:00

cmd-filter.c

block: move holder_dir from disk to part0

2008-10-09 08:56:08 +02:00

compat_ioctl.c

Add BLKDISCARD ioctl to allow userspace to discard sectors

2008-10-09 08:56:02 +02:00

deadline-iosched.c

deadline-iosched: non-functional fixes

2008-10-09 08:56:03 +02:00

elevator.c

block: use linux/uaccess.h in elevator.c instead of asm variant

2008-10-09 08:56:09 +02:00

genhd.c

block: allow disk to have extended device number

2008-10-09 08:56:08 +02:00

ioctl.c

block: make partition array dynamic

2008-10-09 08:56:08 +02:00

Kconfig

block: Block layer data integrity support

2008-07-03 13:21:13 +02:00

Kconfig.iosched

update I/O sched Kconfig help texts - CFQ is now default, not AS.

2007-02-17 20:08:22 +01:00

Makefile

block: split softirq handling into blk-softirq.c

2008-10-09 08:56:09 +02:00

noop-iosched.c

block: let elv_register() return void

2007-12-18 08:29:28 +01:00

scsi_ioctl.c

SG_IO block filter whitelist missing MMC SET READ AHEAD command

2008-10-09 08:56:00 +02:00