kernel-ark/block
Shaohua Li f5f2b6ceb2 CFQ: add think time check for service tree
Currently when the last queue of a service tree has no request, we don't
expire the queue to hope request from the service tree comes soon, so the
service tree doesn't miss its share. But if the think time is big, the
assumption isn't correct and we just waste bandwidth. In such case, we
don't do idle.

[global]
runtime=10
direct=1

[test1]
rw=randread
ioengine=libaio
size=500m
directory=/mnt
filename=file1
thinktime=9000

[test2]
rw=read
ioengine=libaio
size=1G
directory=/mnt
filename=file2

	patched		base
test1	41k/s		33k/s
test2	15868k/s	15789k/s
total	15902k/s	15817k/s

A slightly better

To check if the patch changes behavior of queue without think time. I also
tried to give test1 2ms think time or no think time. The test has variation
even without the patch, but the average throughput doesn't change with/without
the patch.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-07-12 14:24:55 +02:00
..
blk-cgroup.c cgroups: add per-thread subsystem callbacks 2011-05-26 17:12:34 -07:00
blk-cgroup.h cfq-iosched: Make IO merge related stats per cpu 2011-05-23 10:02:19 +02:00
blk-core.c block: avoid building too big plug list 2011-07-08 08:19:20 +02:00
blk-exec.c block: Remove 'plug/unplug' comment in blk_execute_rq_nowait 2011-05-05 15:10:05 -06:00
blk-flush.c block: hold queue if flush is running for non-queueable flush drive 2011-05-06 11:36:25 -06:00
blk-integrity.c dm: improve block integrity support 2011-04-05 23:52:43 +02:00
blk-ioc.c Merge branch 'for-linus' into for-3.1/core 2011-07-01 16:17:13 +02:00
blk-iopoll.c tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
blk-lib.c block: eliminate potential for infinite loop in blkdev_issue_discard 2011-07-06 21:32:02 +02:00
blk-map.c block: check for proper length of iov entries earlier in blk_rq_map_user_iov() 2010-11-29 10:04:50 +01:00
blk-merge.c block: attempt to merge with existing requests on plug flush 2011-03-21 10:14:27 +01:00
blk-settings.c block: Fix discard topology stacking and reporting 2011-05-18 10:37:35 +02:00
blk-softirq.c generic-ipi: remove CSD_FLAG_WAIT 2009-02-25 14:13:44 +01:00
blk-sysfs.c Merge commit 'v2.6.39' into for-2.6.40/core 2011-05-20 20:33:15 +02:00
blk-tag.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
blk-throttle.c blk-throttle: Make total_nr_queued unsigned 2011-06-13 20:19:27 +02:00
blk-timeout.c block: ensure jiffies wrap is handled correctly in blk_rq_timed_out_timer 2010-04-21 17:42:08 +02:00
blk.h Merge branch 'for-linus' into for-2.6.40/core 2011-05-20 20:36:16 +02:00
bsg.c [SCSI] bsg: correct fault if queue object removed while dev_t open 2010-12-09 09:41:14 -06:00
cfq-iosched.c CFQ: add think time check for service tree 2011-07-12 14:24:55 +02:00
cfq.h blk-cgroup: Add unaccounted time to timeslice_used. 2011-03-12 16:54:00 +01:00
compat_ioctl.c compat_ioctl: fix warning caused by qemu 2011-07-01 22:32:26 +02:00
deadline-iosched.c iosched: prevent aliased requests from starving other I/O 2011-06-02 21:19:05 +02:00
elevator.c iosched: prevent aliased requests from starving other I/O 2011-06-02 21:19:05 +02:00
genhd.c block: flush MEDIA_CHANGE from drivers on close(2) 2011-07-01 16:17:47 +02:00
ioctl.c block: fix refcounting in BLKBSZSET 2011-02-24 08:54:21 -08:00
Kconfig kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
Kconfig.iosched blk-cgroup: config options re-arrangement 2010-04-26 19:27:56 +02:00
Makefile Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block 2010-10-22 17:07:18 -07:00
noop-iosched.c block: remove per-queue plugging 2011-03-10 08:52:07 +01:00
scsi_ioctl.c block: take care not to overflow when calculating total iov length 2010-11-10 14:40:42 +01:00