Minchan Kim deb0bdeb2f zram: use atomic operation for stat ... Some of fields in zram->stats are protected by zram->lock which is rather coarse-grained so let's use atomic operation without explict locking. This patch is ready for removing dependency of zram->lock in read path which is very coarse-grained rw_semaphore. Of course, this patch adds new atomic operation so it might make slow but my 12CPU test couldn't spot any regression. All gain/lose is marginal within stddev. iozone -t -T -l 12 -u 12 -r 16K -s 60M -I +Z -V 0 ==Initial write ==Initial write records: 50 records: 50 avg: 412875.17 avg: 415638.23 std: 38543.12 (9.34%) std: 36601.11 (8.81%) max: 521262.03 max: 502976.72 min: 343263.13 min: 351389.12 ==Rewrite ==Rewrite records: 50 records: 50 avg: 416640.34 avg: 397914.33 std: 60798.92 (14.59%) std: 46150.42 (11.60%) max: 543057.07 max: 522669.17 min: 304071.67 min: 316588.77 ==Read ==Read records: 50 records: 50 avg: 4147338.63 avg: 4070736.51 std: 179333.25 (4.32%) std: 223499.89 (5.49%) max: 4459295.28 max: 4539514.44 min: 3753057.53 min: 3444686.31 ==Re-read ==Re-read records: 50 records: 50 avg: 4096706.71 avg: 4117218.57 std: 229735.04 (5.61%) std: 171676.25 (4.17%) max: 4430012.09 max: 4459263.94 min: 2987217.80 min: 3666904.28 ==Reverse Read ==Reverse Read records: 50 records: 50 avg: 4062763.83 avg: 4078508.32 std: 186208.46 (4.58%) std: 172684.34 (4.23%) max: 4401358.78 max: 4424757.22 min: 3381625.00 min: 3679359.94 ==Stride read ==Stride read records: 50 records: 50 avg: 4094933.49 avg: 4082170.22 std: 185710.52 (4.54%) std: 196346.68 (4.81%) max: 4478241.25 max: 4460060.97 min: 3732593.23 min: 3584125.78 ==Random read ==Random read records: 50 records: 50 avg: 4031070.04 avg: 4074847.49 std: 192065.51 (4.76%) std: 206911.33 (5.08%) max: 4356931.16 max: 4399442.56 min: 3481619.62 min: 3548372.44 ==Mixed workload ==Mixed workload records: 50 records: 50 avg: 149925.73 avg: 149675.54 std: 7701.26 (5.14%) std: 6902.09 (4.61%) max: 191301.56 max: 175162.05 min: 133566.28 min: 137762.87 ==Random write ==Random write records: 50 records: 50 avg: 404050.11 avg: 393021.47 std: 58887.57 (14.57%) std: 42813.70 (10.89%) max: 601798.09 max: 524533.43 min: 325176.99 min: 313255.34 ==Pwrite ==Pwrite records: 50 records: 50 avg: 411217.70 avg: 411237.96 std: 43114.99 (10.48%) std: 33136.29 (8.06%) max: 530766.79 max: 471899.76 min: 320786.84 min: 317906.94 ==Pread ==Pread records: 50 records: 50 avg: 4154908.65 avg: 4087121.92 std: 151272.08 (3.64%) std: 219505.04 (5.37%) max: 4459478.12 max: 4435857.38 min: 3730512.41 min: 3101101.67 Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2014-01-30 16:56:55 -08:00
..
aoe	aoe: Convert to immutable biovecs	2013-11-23 22:33:52 -08:00
drbd	block: Immutable bio vecs	2013-11-23 22:33:49 -08:00
mtip32xx	mtip32xx: Correctly handle security locked condition	2014-01-21 20:20:44 -08:00
paride	drivers/block/paride/pg.c: underflow bug in pg_write()	2014-01-21 20:16:56 -08:00
rsxx	block: Convert bio_for_each_segment() to bvec_iter	2013-11-23 22:33:49 -08:00
xen-blkback	block: Abstract out bvec iterator	2013-11-23 22:33:47 -08:00
zram	zram: use atomic operation for stat	2014-01-30 16:56:55 -08:00
amiflop.c	tree-wide: use reinit_completion instead of INIT_COMPLETION	2013-11-15 09:32:21 +09:00
ataflop.c	block_device_operations->release() should return void	2013-05-07 02:16:21 -04:00
brd.c	block: Convert bio_for_each_segment() to bvec_iter	2013-11-23 22:33:49 -08:00
cciss_cmd.h
cciss_scsi.c	cciss: switch to ->show_info()	2013-04-09 14:13:19 -04:00
cciss_scsi.h
cciss.c	drivers/block/cciss.c:cciss_init_one(): use proper errnos	2014-01-21 20:16:56 -08:00
cciss.h
cpqarray.c	cpqarray: fix info leak in ida_locked_ioctl()	2013-09-24 17:00:26 -07:00
cpqarray.h
cryptoloop.c	move linux/loop.h to drivers/block	2013-06-29 12:46:45 +04:00
DAC960.c	procfs: new helper - PDE_DATA(inode)	2013-04-09 14:13:32 -04:00
DAC960.h
floppy.c	floppy: bail out in open() if drive is not responding to block0 read	2014-01-17 11:12:06 +01:00
hd.c
ida_cmd.h
ida_ioctl.h
Kconfig	zram: promote zram from staging	2014-01-30 16:56:55 -08:00
loop.c	drivers/block/loop.c: fix comment typo in loop_config_discard	2014-01-21 20:16:56 -08:00
loop.h	move linux/loop.h to drivers/block	2013-06-29 12:46:45 +04:00
Makefile	zram: promote zram from staging	2014-01-30 16:56:55 -08:00
mg_disk.c	mg_disk: Spelling s/finised/finished/	2014-01-21 20:34:58 -08:00
nbd.c	block: Immutable bio vecs	2013-11-23 22:33:49 -08:00
null_blk.c	Merge branch 'for-3.14/drivers' of git://git.kernel.dk/linux-block	2014-01-30 11:40:10 -08:00
nvme-core.c	block: Introduce new bio_split()	2013-11-23 22:33:57 -08:00
nvme-scsi.c	NVMe: Use kzalloc instead of kmalloc+memset	2013-06-19 13:24:27 -04:00
osdblk.c	block: replace strict_strtoul() with kstrtoul()	2013-09-11 15:56:56 -07:00
pktcdvd.c	pktcdvd: fix error return code	2014-01-03 10:05:34 +01:00
ps3disk.c	block: Kill bio_segments()/bi_vcnt usage	2013-11-23 22:33:51 -08:00
ps3vram.c	block: Convert bio_for_each_segment() to bvec_iter	2013-11-23 22:33:49 -08:00
rbd_types.h
rbd.c	Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block	2014-01-30 11:19:05 -08:00
skd_main.c	drivers: block: Mark the functions as static in skd_main.c	2013-12-19 08:06:49 -07:00
skd_s1120.h	skd: fix formatting in skd_s1120.h	2013-11-08 09:10:30 -07:00
smart1,2.h
sunvdc.c
swim3.c	block_device_operations->release() should return void	2013-05-07 02:16:21 -04:00
swim_asm.S
swim.c	drivers/block/swim.c: remove unnecessary platform_set_drvdata()	2013-09-11 15:56:59 -07:00
sx8.c	drivers/block/sx8.c: remove unnecessary pci_set_drvdata()	2014-01-21 20:16:56 -08:00
umem.c	block: Convert drivers to immutable biovecs	2013-11-23 22:33:51 -08:00
umem.h
virtio_blk.c	virtio-blk: virtqueue_kick() must be ordered with other virtqueue operations	2013-11-19 19:00:45 -07:00
xen-blkfront.c	Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block	2014-01-30 11:19:05 -08:00
xsysace.c	xilinx systemace: Fix sparse warnings	2013-07-10 07:47:12 +02:00
z2ram.c	block/z2ram: Remove duplicate external declarations	2013-11-26 11:09:10 +01:00