Alan D. Brunelle ac9fafa124 block: Skip I/O merges when disabled ...

The block I/O + elevator + I/O scheduler code spend a lot of time trying
to merge I/Os -- rightfully so under "normal" circumstances. However,
if one were to know that the incoming I/O stream was /very/ random in
nature, the cycles are wasted.

This patch adds a per-request_queue tunable that (when set) disables
merge attempts (beyond the simple one-hit cache check), thus freeing up
a non-trivial amount of CPU cycles.

Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2008-04-29 14:48:55 +02:00

..

as-iosched.c

block: kill swap_io_context()

2008-02-01 11:34:49 +01:00

blk-barrier.c

block: rename and export rq_init()

2008-04-29 14:48:55 +02:00

blk-core.c

block: add large command support

2008-04-29 14:48:55 +02:00

blk-exec.c

block: make core bits checkpatch compliant

2008-02-01 09:26:33 +01:00

blk-ioc.c

cfq-iosched: add hlist for browsing parallel to the radix tree

2008-02-19 10:04:00 +01:00

blk-map.c

block: add dma alignment and padding support to blk_rq_map_kern

2008-04-29 09:50:34 +02:00

blk-merge.c

block: make queue flags non-atomic

2008-04-29 14:48:33 +02:00

blk-settings.c

block: make queue flags non-atomic

2008-04-29 14:48:33 +02:00

blk-sysfs.c

block: Skip I/O merges when disabled

2008-04-29 14:48:55 +02:00

blk-tag.c

block: make queue flags non-atomic

2008-04-29 14:48:33 +02:00

blk.h

block: rename and export rq_init()

2008-04-29 14:48:55 +02:00

blktrace.c

blktrace: Add blktrace ioctls to SCSI generic devices

2008-01-28 10:04:46 +01:00

bsg.c

[SCSI] bsg: add release callback support

2008-04-22 15:16:32 -05:00

cfq-iosched.c

cfq-iosched: do not leak ioc_data across iosched switches

2008-04-10 08:28:01 +02:00

compat_ioctl.c

ide: remove broken/dangerous HDIO_[UNREGISTER,SCAN]_HWIF ioctls (take 3)

2008-04-18 00:46:24 +02:00

deadline-iosched.c

block: let elv_register() return void

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

elevator.c

block: Skip I/O merges when disabled

2008-04-29 14:48:55 +02:00

genhd.c

genhd must_check warning fix

2008-03-12 12:34:37 -07:00

ioctl.c

compat_ioctl: move common block ioctls to compat_blkdev_ioctl

2007-10-10 09:26:00 +02:00

Kconfig

Kconfig: clean up block/Kconfig help descriptions

2008-04-21 09:51:04 +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: ll_rw_blk.c split, add blk-merge.c

2008-01-29 21:55:12 +01:00

noop-iosched.c

block: let elv_register() return void

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

scsi_ioctl.c

block: no need to initialize rq->cmd with blk_get_request

2008-04-29 14:48:55 +02:00