<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/block/zram, branch v4.17.1</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v4.17.1</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v4.17.1'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2018-04-06T21:19:26+00:00</updated>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2018-04-06T21:19:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-04-06T21:19:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=3b54765cca23152ec0cc254b75c877c10f6e2870'/>
<id>urn:sha1:3b54765cca23152ec0cc254b75c877c10f6e2870</id>
<content type='text'>
Merge updates from Andrew Morton:

 - a few misc things

 - ocfs2 updates

 - the v9fs maintainers have been missing for a long time. I've taken
   over v9fs patch slinging.

 - most of MM

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (116 commits)
  mm,oom_reaper: check for MMF_OOM_SKIP before complaining
  mm/ksm: fix interaction with THP
  mm/memblock.c: cast constant ULLONG_MAX to phys_addr_t
  headers: untangle kmemleak.h from mm.h
  include/linux/mmdebug.h: make VM_WARN* non-rvals
  mm/page_isolation.c: make start_isolate_page_range() fail if already isolated
  mm: change return type to vm_fault_t
  mm, oom: remove 3% bonus for CAP_SYS_ADMIN processes
  mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory
  kernel/fork.c: detect early free of a live mm
  mm: make counting of list_lru_one::nr_items lockless
  mm/swap_state.c: make bool enable_vma_readahead and swap_vma_readahead() static
  block_invalidatepage(): only release page if the full page was invalidated
  mm: kernel-doc: add missing parameter descriptions
  mm/swap.c: remove @cold parameter description for release_pages()
  mm/nommu: remove description of alloc_vm_area
  zram: drop max_zpage_size and use zs_huge_class_size()
  zsmalloc: introduce zs_huge_class_size()
  mm: fix races between swapoff and flush dcache
  fs/direct-io.c: minor cleanups in do_blockdev_direct_IO
  ...
</content>
</entry>
<entry>
<title>zram: drop max_zpage_size and use zs_huge_class_size()</title>
<updated>2018-04-06T04:36:26+00:00</updated>
<author>
<name>Sergey Senozhatsky</name>
<email>sergey.senozhatsky.work@gmail.com</email>
</author>
<published>2018-04-05T23:24:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=60f5921a9a4f126e081318bd6bb2bc2798b7bba8'/>
<id>urn:sha1:60f5921a9a4f126e081318bd6bb2bc2798b7bba8</id>
<content type='text'>
Remove ZRAM's enforced "huge object" value and use zsmalloc huge-class
watermark instead, which makes more sense.

TEST
- I used a 1G zram device, LZO compression back-end, original
  data set size was 444MB. Looking at zsmalloc classes stats the
  test ended up to be pretty fair.

BASE ZRAM/ZSMALLOC
=====================
zram mm_stat

498978816 191482495 199831552        0 199831552    15634        0

zsmalloc classes

 class  size almost_full almost_empty obj_allocated   obj_used pages_used pages_per_zspage freeable
...
   151  2448           0            0          1240       1240        744                3        0
   168  2720           0            0          4200       4200       2800                2        0
   190  3072           0            0         10100      10100       7575                3        0
   202  3264           0            0           380        380        304                4        0
   254  4096           0            0         10620      10620      10620                1        0

 Total                 7           46        106982     106187      48787                         0

PATCHED ZRAM/ZSMALLOC
=====================

zram mm_stat

498978816 182579184 194248704        0 194248704    15628        0

zsmalloc classes

 class  size almost_full almost_empty obj_allocated   obj_used pages_used pages_per_zspage freeable
...
   151  2448           0            0          1240       1240        744                3        0
   168  2720           0            0          4200       4200       2800                2        0
   190  3072           0            0         10100      10100       7575                3        0
   202  3264           0            0          7180       7180       5744                4        0
   254  4096           0            0          3820       3820       3820                1        0

 Total                 8           45        106959     106193      47424                         0

As we can see, we reduced the number of objects stored in class-4096,
because a huge number of objects which we previously forcibly stored in
class-4096 now stored in non-huge class-3264.  This results in lower
memory consumption:

- zsmalloc now uses 47424 physical pages, which is less than 48787 pages
  zsmalloc used before.

- objects that we store in class-3264 share zspages.  That's why overall
  the number of pages that both class-4096 and class-3264 consumed went
  down from 10924 to 9564.

[sergey.senozhatsky.work@gmail.com: add pool param to zs_huge_class_size()]
  Link: http://lkml.kernel.org/r/20180314081833.1096-3-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20180306070639.7389-3-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Acked-by: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Mike Rapoport &lt;rppt@linux.vnet.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into &lt;linux/blkdev.h&gt;</title>
<updated>2018-03-17T20:45:23+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bart.vanassche@wdc.com</email>
</author>
<published>2018-03-14T22:48:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=233bde21aa43516baa013ef7ac33f3427056db3e'/>
<id>urn:sha1:233bde21aa43516baa013ef7ac33f3427056db3e</id>
<content type='text'>
It happens often while I'm preparing a patch for a block driver that
I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT
available for this driver? Do I have to introduce definitions of these
constants before I can use these constants? To avoid this confusion,
move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the
&lt;linux/blkdev.h&gt; header file such that these become available for all
block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h
header file conditional to avoid that including that header file after
&lt;linux/blkdev.h&gt; causes the compiler to complain about a SECTOR_SIZE
redefinition.

Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have
not been removed from uapi header files nor from NAND drivers in
which these constants are used for another purpose than converting
block layer offsets and sizes into a number of sectors.

Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Nitin Gupta &lt;ngupta@vflare.org&gt;
Reviewed-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Johannes Thumshirn &lt;jthumshirn@suse.de&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: Bart Van Assche &lt;bart.vanassche@wdc.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>block: Use blk_queue_flag_*() in drivers instead of queue_flag_*()</title>
<updated>2018-03-08T21:13:48+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bart.vanassche@wdc.com</email>
</author>
<published>2018-03-08T01:10:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8b904b5b6b58b9a29dcf3f82d936d9e7fd69fda6'/>
<id>urn:sha1:8b904b5b6b58b9a29dcf3f82d936d9e7fd69fda6</id>
<content type='text'>
This patch has been generated as follows:

for verb in set_unlocked clear_unlocked set clear; do
  replace-in-files queue_flag_${verb} blk_queue_flag_${verb%_unlocked} \
    $(git grep -lw queue_flag_${verb} drivers block/bsg*)
done

Except for protecting all queue flag changes with the queue lock
this patch does not change any functionality.

Cc: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: Shaohua Li &lt;shli@fb.com&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Hannes Reinecke &lt;hare@suse.de&gt;
Cc: Ming Lei &lt;ming.lei@redhat.com&gt;
Signed-off-by: Bart Van Assche &lt;bart.vanassche@wdc.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Reviewed-by: Johannes Thumshirn &lt;jthumshirn@suse.de&gt;
Acked-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>zram: Delete gendisk before cleaning up the request queue</title>
<updated>2018-02-28T19:23:35+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bart.vanassche@wdc.com</email>
</author>
<published>2018-02-28T18:15:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=392db38058eb47250a9d0cc737af37e78a7e443d'/>
<id>urn:sha1:392db38058eb47250a9d0cc737af37e78a7e443d</id>
<content type='text'>
Remove the disk, partition and bdi sysfs attributes before cleaning up
the request queue associated with the disk.

Signed-off-by: Bart Van Assche &lt;bart.vanassche@wdc.com&gt;
Reviewed-by: Johannes Thumshirn &lt;jthumshirn@suse.de&gt;
Reviewed-by: Joseph Qi &lt;joseph.qi@linux.alibaba.com&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Nitin Gupta &lt;ngupta@vflare.org&gt;
Cc: Sergey Senozhatsky &lt;sergey.senozhatsky.work@gmail.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>block: convert to bio_first_bvec_all &amp; bio_first_page_all</title>
<updated>2018-01-06T16:18:00+00:00</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2017-12-18T12:22:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=263663cd3c4fbfc40cb7504c4be2dadbc0992cc1'/>
<id>urn:sha1:263663cd3c4fbfc40cb7504c4be2dadbc0992cc1</id>
<content type='text'>
This patch converts to bio_first_bvec_all() &amp; bio_first_page_all() for
retrieving the 1st bvec/page, and prepares for supporting multipage bvec.

Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>drivers/block/zram/zram_drv.c: make zram_page_end_io() static</title>
<updated>2017-11-16T02:21:05+00:00</updated>
<author>
<name>Colin Ian King</name>
<email>colin.king@canonical.com</email>
</author>
<published>2017-11-16T01:37:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=384bc41fc064bd8b12b7081aa3e81d26f3407045'/>
<id>urn:sha1:384bc41fc064bd8b12b7081aa3e81d26f3407045</id>
<content type='text'>
zram_page_end_io() is local to the source and does not need to be in
global scope, so make it static.

Cleans up sparse warning:

  symbol 'zram_page_end_io' was not declared. Should it be static?

Link: http://lkml.kernel.org/r/20171016173336.20320-1-colin.king@canonical.com
Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Reviewed-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>zram: remove zlib from the list of recommended algorithms</title>
<updated>2017-11-16T02:21:03+00:00</updated>
<author>
<name>Sergey Senozhatsky</name>
<email>sergey.senozhatsky.work@gmail.com</email>
</author>
<published>2017-11-16T01:33:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=0b07ff3972061a5e06e168378dd578801ae3e88e'/>
<id>urn:sha1:0b07ff3972061a5e06e168378dd578801ae3e88e</id>
<content type='text'>
ZSTD tends to outperform deflate/inflate, thus we remove zlib from the
list of recommended algorithms and recommend zstd instead.

Link: http://lkml.kernel.org/r/20170912050005.3247-2-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Suggested-by: Minchan Kim &lt;minchan@kernel.org&gt;
Acked-by: Minchan Kim &lt;minchan@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>zram: add zstd to the supported algorithms list</title>
<updated>2017-11-16T02:21:03+00:00</updated>
<author>
<name>Sergey Senozhatsky</name>
<email>sergey.senozhatsky.work@gmail.com</email>
</author>
<published>2017-11-16T01:33:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5ef3a8b12556d7fcba81edc74e9d85b029615ae0'/>
<id>urn:sha1:5ef3a8b12556d7fcba81edc74e9d85b029615ae0</id>
<content type='text'>
Add ZSTD to the list of supported compression algorithms.

ZRAM fio perf test:

                      LZO         DEFLATE         ZSTD

#jobs1
WRITE:              (2180MB/s)   (77.2MB/s)      (1429MB/s)
WRITE:              (1617MB/s)   (77.7MB/s)      (1202MB/s)
READ:                (426MB/s)   (595MB/s)       (1181MB/s)
READ:                (422MB/s)   (572MB/s)       (1020MB/s)
READ:                (318MB/s)   (67.8MB/s)      (563MB/s)
WRITE:               (318MB/s)   (67.9MB/s)      (564MB/s)
READ:                (336MB/s)   (68.3MB/s)      (583MB/s)
WRITE:               (335MB/s)   (68.2MB/s)      (582MB/s)
#jobs2
WRITE:              (3441MB/s)   (152MB/s)       (2141MB/s)
WRITE:              (2507MB/s)   (147MB/s)       (1888MB/s)
READ:                (801MB/s)   (1146MB/s)      (1890MB/s)
READ:                (767MB/s)   (1096MB/s)      (2073MB/s)
READ:                (621MB/s)   (126MB/s)       (1009MB/s)
WRITE:               (621MB/s)   (126MB/s)       (1009MB/s)
READ:                (656MB/s)   (125MB/s)       (1075MB/s)
WRITE:               (657MB/s)   (126MB/s)       (1077MB/s)
#jobs3
WRITE:              (4772MB/s)   (225MB/s)       (3394MB/s)
WRITE:              (3905MB/s)   (211MB/s)       (2939MB/s)
READ:               (1216MB/s)   (1608MB/s)      (3218MB/s)
READ:               (1159MB/s)   (1431MB/s)      (2981MB/s)
READ:                (906MB/s)   (156MB/s)       (1457MB/s)
WRITE:               (907MB/s)   (156MB/s)       (1458MB/s)
READ:                (953MB/s)   (158MB/s)       (1595MB/s)
WRITE:               (952MB/s)   (157MB/s)       (1593MB/s)
#jobs4
WRITE:              (6036MB/s)   (265MB/s)       (4469MB/s)
WRITE:              (5059MB/s)   (263MB/s)       (3951MB/s)
READ:               (1618MB/s)   (2066MB/s)      (4276MB/s)
READ:               (1573MB/s)   (1942MB/s)      (3830MB/s)
READ:               (1202MB/s)   (227MB/s)       (1971MB/s)
WRITE:              (1200MB/s)   (227MB/s)       (1968MB/s)
READ:               (1265MB/s)   (226MB/s)       (2116MB/s)
WRITE:              (1264MB/s)   (226MB/s)       (2114MB/s)
#jobs5
WRITE:              (5339MB/s)   (233MB/s)       (3781MB/s)
WRITE:              (4298MB/s)   (234MB/s)       (3276MB/s)
READ:               (1626MB/s)   (2048MB/s)      (4081MB/s)
READ:               (1567MB/s)   (1929MB/s)      (3758MB/s)
READ:               (1174MB/s)   (205MB/s)       (1747MB/s)
WRITE:              (1173MB/s)   (204MB/s)       (1746MB/s)
READ:               (1214MB/s)   (208MB/s)       (1890MB/s)
WRITE:              (1215MB/s)   (208MB/s)       (1892MB/s)
#jobs6
WRITE:              (5666MB/s)   (270MB/s)       (4338MB/s)
WRITE:              (4828MB/s)   (267MB/s)       (3772MB/s)
READ:               (1803MB/s)   (2058MB/s)      (4946MB/s)
READ:               (1805MB/s)   (2156MB/s)      (4711MB/s)
READ:               (1334MB/s)   (235MB/s)       (2135MB/s)
WRITE:              (1335MB/s)   (235MB/s)       (2137MB/s)
READ:               (1364MB/s)   (236MB/s)       (2268MB/s)
WRITE:              (1365MB/s)   (237MB/s)       (2270MB/s)
#jobs7
WRITE:              (5474MB/s)   (270MB/s)       (4300MB/s)
WRITE:              (4666MB/s)   (266MB/s)       (3817MB/s)
READ:               (2022MB/s)   (2319MB/s)      (5472MB/s)
READ:               (1924MB/s)   (2260MB/s)      (5031MB/s)
READ:               (1369MB/s)   (242MB/s)       (2153MB/s)
WRITE:              (1370MB/s)   (242MB/s)       (2155MB/s)
READ:               (1499MB/s)   (246MB/s)       (2310MB/s)
WRITE:              (1497MB/s)   (246MB/s)       (2307MB/s)
#jobs8
WRITE:              (5558MB/s)   (273MB/s)       (4439MB/s)
WRITE:              (4763MB/s)   (271MB/s)       (3918MB/s)
READ:               (2201MB/s)   (2599MB/s)      (6062MB/s)
READ:               (2105MB/s)   (2463MB/s)      (5413MB/s)
READ:               (1490MB/s)   (252MB/s)       (2238MB/s)
WRITE:              (1488MB/s)   (252MB/s)       (2236MB/s)
READ:               (1566MB/s)   (254MB/s)       (2434MB/s)
WRITE:              (1568MB/s)   (254MB/s)       (2437MB/s)
#jobs9
WRITE:              (5120MB/s)   (264MB/s)       (4035MB/s)
WRITE:              (4531MB/s)   (267MB/s)       (3740MB/s)
READ:               (1940MB/s)   (2258MB/s)      (4986MB/s)
READ:               (2024MB/s)   (2387MB/s)      (4871MB/s)
READ:               (1343MB/s)   (246MB/s)       (2038MB/s)
WRITE:              (1342MB/s)   (246MB/s)       (2037MB/s)
READ:               (1553MB/s)   (238MB/s)       (2243MB/s)
WRITE:              (1552MB/s)   (238MB/s)       (2242MB/s)
#jobs10
WRITE:              (5345MB/s)   (271MB/s)       (3988MB/s)
WRITE:              (4750MB/s)   (254MB/s)       (3668MB/s)
READ:               (1876MB/s)   (2363MB/s)      (5150MB/s)
READ:               (1990MB/s)   (2256MB/s)      (5080MB/s)
READ:               (1355MB/s)   (250MB/s)       (2019MB/s)
WRITE:              (1356MB/s)   (251MB/s)       (2020MB/s)
READ:               (1490MB/s)   (252MB/s)       (2202MB/s)
WRITE:              (1488MB/s)   (252MB/s)       (2199MB/s)

jobs1                              perfstat
instructions                 52,065,555,710 (    0.79)    855,731,114,587 (    2.64)       54,280,709,944 (    1.40)
branches                     14,020,427,116 ( 725.847)    101,733,449,582 (1074.521)       11,170,591,067 ( 992.869)
branch-misses                    22,626,174 (   0.16%)        274,197,885 (   0.27%)           25,915,805 (   0.23%)
jobs2                              perfstat
instructions                103,633,110,402 (    0.75)  1,710,822,100,914 (    2.59)      107,879,874,104 (    1.28)
branches                     27,931,237,282 ( 679.203)    203,298,267,479 (1037.326)       22,185,350,842 ( 884.427)
branch-misses                    46,103,811 (   0.17%)        533,747,204 (   0.26%)           49,682,483 (   0.22%)
jobs3                              perfstat
instructions                154,857,283,657 (    0.76)  2,565,748,974,197 (    2.57)      161,515,435,813 (    1.31)
branches                     41,759,490,355 ( 670.529)    304,905,605,277 ( 978.765)       33,215,805,907 ( 888.003)
branch-misses                    74,263,293 (   0.18%)        759,746,240 (   0.25%)           76,841,196 (   0.23%)
jobs4                              perfstat
instructions                206,215,849,076 (    0.75)  3,420,169,460,897 (    2.60)      215,003,061,664 (    1.31)
branches                     55,632,141,739 ( 666.501)    406,394,977,433 ( 927.241)       44,214,322,251 ( 883.532)
branch-misses                   102,287,788 (   0.18%)      1,098,617,314 (   0.27%)          103,891,040 (   0.23%)
jobs5                              perfstat
instructions                258,711,315,588 (    0.67)  4,275,657,533,244 (    2.23)      269,332,235,685 (    1.08)
branches                     69,802,821,166 ( 588.823)    507,996,211,252 ( 797.036)       55,450,846,129 ( 735.095)
branch-misses                   129,217,214 (   0.19%)      1,243,284,991 (   0.24%)          173,512,278 (   0.31%)
jobs6                              perfstat
instructions                312,796,166,008 (    0.61)  5,133,896,344,660 (    2.02)      323,658,769,588 (    1.04)
branches                     84,372,488,583 ( 520.541)    610,310,494,402 ( 697.642)       66,683,292,992 ( 693.939)
branch-misses                   159,438,978 (   0.19%)      1,396,368,563 (   0.23%)          174,406,934 (   0.26%)
jobs7                              perfstat
instructions                363,211,372,930 (    0.56)  5,988,205,600,879 (    1.75)      377,824,674,156 (    0.93)
branches                     98,057,013,765 ( 463.117)    711,841,255,974 ( 598.762)       77,879,009,954 ( 600.443)
branch-misses                   199,513,153 (   0.20%)      1,507,651,077 (   0.21%)          248,203,369 (   0.32%)
jobs8                              perfstat
instructions                413,960,354,615 (    0.52)  6,842,918,558,378 (    1.45)      431,938,486,581 (    0.83)
branches                    111,812,574,884 ( 414.224)    813,299,084,518 ( 491.173)       89,062,699,827 ( 517.795)
branch-misses                   233,584,845 (   0.21%)      1,531,593,921 (   0.19%)          286,818,489 (   0.32%)
jobs9                              perfstat
instructions                465,976,220,300 (    0.53)  7,698,467,237,372 (    1.47)      486,352,600,321 (    0.84)
branches                    125,931,456,162 ( 424.063)    915,207,005,715 ( 498.192)      100,370,404,090 ( 517.439)
branch-misses                   256,992,445 (   0.20%)      1,782,809,816 (   0.19%)          345,239,380 (   0.34%)
jobs10                             perfstat
instructions                517,406,372,715 (    0.53)  8,553,527,312,900 (    1.48)      540,732,653,094 (    0.84)
branches                    139,839,780,676 ( 427.732)  1,016,737,699,389 ( 503.172)      111,696,557,638 ( 516.750)
branch-misses                   259,595,561 (   0.19%)      1,952,570,279 (   0.19%)          357,818,661 (   0.32%)

seconds elapsed        20.630411534     96.084546565    12.743373571
seconds elapsed        22.292627625     100.984155001   14.407413560
seconds elapsed        22.396016966     110.344880848   14.032201392
seconds elapsed        22.517330949     113.351459170   14.243074935
seconds elapsed        28.548305104     156.515193765   19.159286861
seconds elapsed        30.453538116     164.559937678   19.362492717
seconds elapsed        33.467108086     188.486827481   21.492612173
seconds elapsed        35.617727591     209.602677783   23.256422492
seconds elapsed        42.584239509     243.959902566   28.458540338
seconds elapsed        47.683632526     269.635248851   31.542404137

Over all, ZSTD has slower WRITE, but much faster READ (perhaps
a static compression buffer used during the test helped ZSTD a
lot), which results in faster test results.

Memory consumption (zram mm_stat file):

zram LZO mm_stat
mm_stat (jobs1): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs2): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs3): 2147483648 23068672 33558528        0 33562624        0        0
mm_stat (jobs4): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs5): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs6): 2147483648 23068672 33558528        0 33562624        0        0
mm_stat (jobs7): 2147483648 23068672 33558528        0 33566720        0        0
mm_stat (jobs8): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs9): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs10): 2147483648 23068672 33558528        0 33562624        0        0

zram DEFLATE mm_stat
mm_stat (jobs1): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs2): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs3): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs4): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs5): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs6): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs7): 2147483648 16252928 25178112        0 25190400        0        0
mm_stat (jobs8): 2147483648 16252928 25178112        0 25190400        0        0
mm_stat (jobs9): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs10): 2147483648 16252928 25178112        0 25178112        0        0

zram ZSTD mm_stat
mm_stat (jobs1): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs2): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs3): 2147483648 11010048 16781312        0 16785408        0        0
mm_stat (jobs4): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs5): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs6): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs7): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs8): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs9): 2147483648 11010048 16781312        0 16785408        0        0
mm_stat (jobs10): 2147483648 11010048 16781312        0 16781312        0        0

==================================================================================

Official benchmarks [1]:

Compressor name         Ratio   Compression     Decompress.
zstd 1.1.3 -1           2.877   430 MB/s        1110 MB/s
zlib 1.2.8 -1           2.743   110 MB/s        400 MB/s
brotli 0.5.2 -0         2.708   400 MB/s        430 MB/s
quicklz 1.5.0 -1        2.238   550 MB/s        710 MB/s
lzo1x 2.09 -1           2.108   650 MB/s        830 MB/s
lz4 1.7.5               2.101   720 MB/s        3600 MB/s
snappy 1.1.3            2.091   500 MB/s        1650 MB/s
lzf 3.6 -1              2.077   400 MB/s        860 MB/s

Minchan said:

: I did test with my sample data and compared zstd with deflate.  zstd's
: compress ratio is lower a little bit but compression speed is much faster
: 3 times more and decompress speed is too 2 times more.  With different
: data, it is different but overall, zstd would be better for speed at the
: cost of a little lower compress ratio(about 5%) so I believe it's worth to
: replace deflate.

[1] https://github.com/facebook/zstd

Link: http://lkml.kernel.org/r/20170912050005.3247-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Acked-by: Minchan Kim &lt;minchan@kernel.org&gt;
Tested-by: Minchan Kim &lt;minchan@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>bdi: introduce BDI_CAP_SYNCHRONOUS_IO</title>
<updated>2017-11-16T02:21:02+00:00</updated>
<author>
<name>Minchan Kim</name>
<email>minchan@kernel.org</email>
</author>
<published>2017-11-16T01:33:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=23c47d2ada9f96731492a67b28c0072715075baa'/>
<id>urn:sha1:23c47d2ada9f96731492a67b28c0072715075baa</id>
<content type='text'>
As discussed at

  https://lkml.kernel.org/r/&lt;20170728165604.10455-1-ross.zwisler@linux.intel.com&gt;

someday we will remove rw_page().  If so, we need something to detect
such super-fast storage on which synchronous IO operations like the
current rw_page are always a win.

Introduces BDI_CAP_SYNCHRONOUS_IO to indicate such devices.  With it, we
could use various optimization techniques.

Link: http://lkml.kernel.org/r/1505886205-9671-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: Hugh Dickins &lt;hughd@google.com&gt;
Cc: Ilya Dryomov &lt;idryomov@gmail.com&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Cc: Huang Ying &lt;ying.huang@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
</feed>
