linux/block
Tejun Heo 11a3122f6c block: strip out locking optimization in put_io_context()
put_io_context() performed a complex trylock dancing to avoid
deferring ioc release to workqueue.  It was also broken on UP because
trylock was always assumed to succeed which resulted in unbalanced
preemption count.

While there are ways to fix the UP breakage, even the most
pathological microbench (forced ioc allocation and tight fork/exit
loop) fails to show any appreciable performance benefit of the
optimization.  Strip it out.  If there turns out to be workloads which
are affected by this change, simpler optimization from the discussion
thread can be applied later.

Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <1328514611.21268.66.camel@sli10-conroe>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-02-07 07:51:30 +01:00
..
partitions separate partition format handling from generic code 2012-01-03 22:54:06 -05:00
Kconfig move fs/partitions to block/ 2012-01-03 22:54:06 -05:00
Kconfig.iosched blk-cgroup: config options re-arrangement 2010-04-26 19:27:56 +02:00
Makefile separate partition format handling from generic code 2012-01-03 22:54:06 -05:00
blk-cgroup.c block: strip out locking optimization in put_io_context() 2012-02-07 07:51:30 +01:00
blk-cgroup.h block: fix a typo in the blk-cgroup.h file 2011-10-24 16:08:38 +02:00
blk-core.c block: strip out locking optimization in put_io_context() 2012-02-07 07:51:30 +01:00
blk-exec.c block: add missing blk_queue_dead() checks 2011-12-14 00:33:37 +01:00
blk-flush.c blk-flush: move the queue kick into 2011-10-24 16:24:31 +02:00
blk-integrity.c block: add export.h to files using EXPORT_SYMBOL/THIS_MODULE macros 2011-10-31 19:31:12 -04:00
blk-ioc.c block: strip out locking optimization in put_io_context() 2012-02-07 07:51:30 +01:00
blk-iopoll.c tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
blk-lib.c block: fix patch import error in max_discard_sectors check 2011-07-23 20:34:59 +02:00
blk-map.c block: re-use existing 'reading' variable instead of checking direction again 2011-12-21 15:27:24 +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: Introduce blk_set_stacking_limits function 2012-01-11 16:27:11 +01:00
blk-softirq.c block: Don't check QUEUE_FLAG_SAME_COMP in __blk_complete_request 2011-09-14 09:31:01 +02:00
blk-sysfs.c block, cfq: move io_cq exit/release to blk-ioc.c 2011-12-14 00:33:42 +01:00
blk-tag.c block: fix blk_queue_end_tag() 2011-12-29 09:16:28 +01:00
blk-throttle.c block: add blk_queue_dead() 2011-12-14 00:33:37 +01:00
blk-timeout.c fault-injection: add ability to export fault_attr in arbitrary directory 2011-08-03 14:25:20 -10:00
blk.h block, cfq: move icq creation and rq->elv.icq association to block core 2011-12-14 00:33:42 +01:00
bsg-lib.c block: Change module.h -> export.h in bsg-lib.c 2011-10-31 19:31:13 -04:00
bsg.c Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block 2012-01-15 12:24:45 -08:00
cfq-iosched.c block: strip out locking optimization in put_io_context() 2012-02-07 07:51:30 +01:00
cfq.h blk-cgroup: Add unaccounted time to timeslice_used. 2011-03-12 16:54:00 +01:00
compat_ioctl.c block: Add BLKROTATIONAL ioctl 2012-01-11 16:29:31 +01:00
deadline-iosched.c block, cfq: move icq cache management to block core 2011-12-14 00:33:42 +01:00
elevator.c Revert "block: recursive merge requests" 2012-01-15 10:29:48 +01:00
genhd.c Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block 2012-01-15 12:24:45 -08:00
ioctl.c Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block 2012-01-15 12:24:45 -08:00
noop-iosched.c block, cfq: move icq cache management to block core 2011-12-14 00:33:42 +01:00
partition-generic.c separate partition format handling from generic code 2012-01-03 22:54:06 -05:00
scsi_ioctl.c block: fail SCSI passthrough ioctls on partition devices 2012-01-14 15:07:24 -08:00