linux-stable/drivers/block
karam.lee 8c7f01025f zram: implement rw_page operation of zram
This patch implements rw_page operation for zram block device.

I implemented the feature in zram and tested it.  Test bed was the G2, LG
electronic mobile device, whtich has msm8974 processor and 2GB memory.

With a memory allocation test program consuming memory, the system
generates swap.

Operating time of swap_write_page() was measured.

--------------------------------------------------
|             |   operating time   | improvement |
|             |  (20 runs average) |             |
--------------------------------------------------
|with patch   |    1061.15 us      |    +2.4%    |
--------------------------------------------------
|without patch|    1087.35 us      |             |
--------------------------------------------------

Each test(with paged_io,with BIO) result set shows normal distribution and
has equal variance.  I mean the two values are valid result to compare.  I
can say operation with paged I/O(without BIO) is faster 2.4% with
confidence level 95%.

[minchan@kernel.org: make rw_page opeartion return 0]
[minchan@kernel.org: rely on the bi_end_io for zram_rw_page fails]
[sergey.senozhatsky@gmail.com: code cleanup]
[minchan@kernel.org: add comment]
Signed-off-by: karam.lee <karam.lee@lge.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: <seungho1.park@lge.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00
..
aoe mm: close PageTail race 2014-03-04 07:55:47 -08:00
drbd kill f_dentry uses 2014-11-19 13:01:25 -05:00
mtip32xx Merge branch 'for-3.18/drivers' of git://git.kernel.dk/linux-block 2014-10-18 12:12:45 -07:00
paride Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block 2014-10-18 11:53:51 -07:00
rsxx Merge branch 'for-3.18/drivers' of git://git.kernel.dk/linux-block 2014-10-18 12:12:45 -07:00
xen-blkback Merge branch 'for-3.18/drivers' of git://git.kernel.dk/linux-block 2014-10-18 12:12:45 -07:00
zram zram: implement rw_page operation of zram 2014-12-13 12:42:50 -08:00
amiflop.c block: remove struct request buffer member 2014-04-15 14:03:02 -06:00
ataflop.c Merge branch 'for-3.16/core' of git://git.kernel.dk/linux-block into next 2014-06-02 09:29:34 -07:00
brd.c brd: add ram disk visibility option 2014-08-21 20:42:01 -05:00
cciss.c block: use pci_zalloc_consistent 2014-08-08 15:57:28 -07:00
cciss.h
cciss_cmd.h
cciss_scsi.c
cciss_scsi.h
cpqarray.c
cpqarray.h
cryptoloop.c
DAC960.c block: use pci_zalloc_consistent 2014-08-08 15:57:28 -07:00
DAC960.h
floppy.c Merge branch 'for-jens' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/linux-block into for-linus 2014-06-18 10:30:22 -07:00
hd.c block: hd: remove deprecated IRQF_DISABLED 2014-10-01 08:16:07 -06:00
ida_cmd.h
ida_ioctl.h
Kconfig zram: promote zram from staging 2014-01-30 16:56:55 -08:00
loop.c Merge branch 'sched/urgent' into sched/core, to avoid conflicts 2014-05-07 13:15:46 +02:00
loop.h
Makefile zram: promote zram from staging 2014-01-30 16:56:55 -08:00
mg_disk.c block: remove struct request buffer member 2014-04-15 14:03:02 -06:00
nbd.c block: disable entropy contributions for nonrot devices 2014-10-04 10:55:32 -06:00
null_blk.c null_blk: Cleanup error recovery in null_add_dev() 2014-10-22 07:59:25 -06:00
nvme-core.c block: disable entropy contributions for nonrot devices 2014-10-04 10:55:32 -06:00
nvme-scsi.c scsi: rename SERVICE_ACTION_IN to SERVICE_ACTION_IN_16 2014-11-24 20:01:40 +01:00
osdblk.c
pktcdvd.c block,scsi: fixup blk_get_request dead queue scenarios 2014-08-28 10:03:46 -06:00
ps3disk.c
ps3vram.c
rbd.c rbd: Fix error recovery in rbd_obj_read_sync() 2014-10-30 13:11:51 +03:00
rbd_types.h
skd_main.c block: disable entropy contributions for nonrot devices 2014-10-04 10:55:32 -06:00
skd_s1120.h
smart1,2.h
sunvdc.c sunvdc: don't call VD_OP_GET_VTOC 2014-10-31 15:49:45 -04:00
swim.c block: remove struct request buffer member 2014-04-15 14:03:02 -06:00
swim3.c block: remove struct request buffer member 2014-04-15 14:03:02 -06:00
swim_asm.S
sx8.c block,scsi: fixup blk_get_request dead queue scenarios 2014-08-28 10:03:46 -06:00
umem.c
umem.h
virtio_blk.c virtio: drop VIRTIO_F_VERSION_1 from drivers 2014-12-09 12:06:32 +02:00
xen-blkfront.c Merge branch 'for-3.18/drivers' of git://git.kernel.dk/linux-block 2014-10-18 12:12:45 -07:00
xsysace.c block: systemace: Remove .owner field for driver 2014-08-21 20:37:54 -05:00
z2ram.c block: remove struct request buffer member 2014-04-15 14:03:02 -06:00