提交 · 0bea803e9e6bf3836d5368a6426c30a8c0e5eab5 · openeuler / Kernel

16 11月, 2017 40 次提交

mm/hmm: constify hmm_devmem_page_get_drvdata() parameter · 0bea803e

由 Ralph Campbell 提交于 11月 15, 2017

Constify pointer parameter to avoid issue when use from code that only
has const struct page pointer to use in the first place.

Link: http://lkml.kernel.org/r/1506972774-10191-1-git-send-email-jglisse@redhat.comSigned-off-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NJérôme Glisse <jglisse@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

0bea803e

fs/hugetlbfs/inode.c: remove redundant -ENIVAL return from hugetlbfs_setattr() · 007ab7b4

由 Anshuman Khandual 提交于 11月 15, 2017

There is no need to have a local return code set with -EINVAL when both
the conditions following it return error codes appropriately. Just
remove the redundant one.

Link: http://lkml.kernel.org/r/20170929145444.17611-1-khandual@linux.vnet.ibm.comSigned-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com>
Reviewed-by: NMike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

007ab7b4

zram: remove zlib from the list of recommended algorithms · 0b07ff39

由 Sergey Senozhatsky 提交于 11月 15, 2017

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.comSigned-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NMinchan Kim <minchan@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

0b07ff39

zram: add zstd to the supported algorithms list · 5ef3a8b1

由 Sergey Senozhatsky 提交于 11月 15, 2017

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.comSigned-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Tested-by: NMinchan Kim <minchan@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

5ef3a8b1

mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical · 0f6d24f8

由 Yafang Shao 提交于 11月 15, 2017

The vm direct limit setting must be set greater than vm background limit
setting. Otherwise print a warning to help the operator to figure out
that the vm dirtiness settings is in illogical state.

Link: http://lkml.kernel.org/r/1506592464-30962-1-git-send-email-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

0f6d24f8

mm/memblock.c: make the index explicit argument of for_each_memblock_type · 66e8b438

由 Gioh Kim 提交于 11月 15, 2017

for_each_memblock_type macro function relies on idx variable defined in
the caller context. Silent macro arguments are almost always wrong
thing to do. They make code harder to read and easier to get wrong.
Let's use an explicit iterator parameter for for_each_memblock_type and
make the code more obious. This patch is a mere cleanup and it
shouldn't introduce any functional change.

Link: http://lkml.kernel.org/r/20170913133029.28911-1-gi-oh.kim@profitbricks.comSigned-off-by: NGioh Kim <gi-oh.kim@profitbricks.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

66e8b438

mm, memory_hotplug: remove timeout from __offline_memory · ecde0f3e

由 Michal Hocko 提交于 11月 15, 2017

We have a hardcoded 120s timeout after which the memory offline fails
basically since the hot remove has been introduced.  This is essentially
a policy implemented in the kernel.  Moreover there is no way to adjust
the timeout and so we are sometimes facing memory offline failures if
the system is under a heavy memory pressure or very intensive CPU
workload on large machines.

It is not very clear what purpose the timeout actually serves.  The
offline operation is interruptible by a signal so if userspace wants
some timeout based termination this can be done trivially by sending a
signal.

If there is a strong usecase to do this from the kernel then we should
do it properly and have a it tunable from the userspace with the timeout
disabled by default along with the explanation who uses it and for what
purporse.

Link: http://lkml.kernel.org/r/20170918070834.13083-3-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ecde0f3e

mm, memory_hotplug: do not fail offlining too early · 72b39cfc

由 Michal Hocko 提交于 11月 15, 2017

Patch series "mm, memory_hotplug: redefine memory offline retry logic", v2.

While testing memory hotplug on a large 4TB machine we have noticed that
memory offlining is just too eager to fail.  The primary reason is that
the retry logic is just too easy to give up.  We have 4 ways out of the
offline

	- we have a permanent failure (isolation or memory notifiers fail,
	  or hugetlb pages cannot be dropped)
	- userspace sends a signal
	- a hardcoded 120s timeout expires
	- page migration fails 5 times

This is way too convoluted and it doesn't scale very well.  We have seen
both temporary migration failures as well as 120s being triggered.
After removing those restrictions we were able to pass stress testing
during memory hot remove without any other negative side effects
observed.  Therefore I suggest dropping both hard coded policies.  I
couldn't have found any specific reason for them in the changelog.  I
neither didn't get any response [1] from Kamezawa.  If we need some
upper bound - e.g.  timeout based - then we should have a proper and
user defined policy for that.  In any case there should be a clear use
case when introducing it.

This patch (of 2):

Memory offlining can fail too eagerly under heavy memory pressure.

  page:ffffea22a646bd00 count:255 mapcount:252 mapping:ffff88ff926c9f38 index:0x3
  flags: 0x9855fe40010048(uptodate|active|mappedtodisk)
  page dumped because: isolation failed
  page->mem_cgroup:ffff8801cd662000
  memory offlining [mem 0x18b580000000-0x18b5ffffffff] failed

Isolation has failed here because the page is not on LRU.  Most probably
because it was on the pcp LRU cache or it has been removed from the LRU
already but it hasn't been freed yet.  In both cases the page doesn't
look non-migrable so retrying more makes sense.

__offline_pages seems rather cluttered when it comes to the retry logic.
We have 5 retries at maximum and a timeout.  We could argue whether the
timeout makes sense but failing just because of a race when somebody
isoltes a page from LRU or puts it on a pcp LRU lists is just wrong.  It
only takes it to race with a process which unmaps some pages and remove
them from the LRU list and we can fail the whole offline because of
something that is a temporary condition and actually not harmful for the
offline.

Please note that unmovable pages should be already excluded during
start_isolate_page_range.  We could argue that has_unmovable_pages is
racy and MIGRATE_MOVABLE check doesn't provide any hard guarantee either
but kernel zones (aka < ZONE_MOVABLE) will very likely detect unmovable
pages in most cases and movable zone shouldn't contain unmovable pages
at all.  Some of those pages might be pinned but not for ever because
that would be a bug on its own.  In any case the context is still
interruptible and so the userspace can easily bail out when the
operation takes too long.  This is certainly better behavior than a
hardcoded retry loop which is racy.

Fix this by removing the max retry count and only rely on the timeout
resp. interruption by a signal from the userspace.  Also retry rather
than fail when check_pages_isolated sees some !free pages because those
could be a result of the race as well.

Link: http://lkml.kernel.org/r/20170918070834.13083-2-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

72b39cfc

mm, page_alloc: fail has_unmovable_pages when seeing reserved pages · d7ab3672

由 Michal Hocko 提交于 11月 15, 2017

Reserved pages should be completely ignored by the core mm because they
have a special meaning for their owners.  has_unmovable_pages doesn't
check those so we rely on other tests (reference count, or PageLRU) to
fail on such pages.  Althought this happens to work it is safer to
simply check for those explicitly and do not rely on the owner of the
page to abuse those fields for special purposes.

Please note that this is more of a further fortification of the code
rahter than a fix of an existing issue.

Link: http://lkml.kernel.org/r/20171013120756.jeopthigbmm3c7bl@dhcp22.suse.czSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

d7ab3672

mm: distinguish CMA and MOVABLE isolation in has_unmovable_pages() · 4da2ce25

由 Michal Hocko 提交于 11月 15, 2017

Joonsoo has noticed that "mm: drop migrate type checks from
has_unmovable_pages" would break CMA allocator because it relies on
has_unmovable_pages returning false even for CMA pageblocks which in
fact don't have to be movable:

 alloc_contig_range
   start_isolate_page_range
     set_migratetype_isolate
       has_unmovable_pages

This is a result of the code sharing between CMA and memory hotplug
while each one has a different idea of what has_unmovable_pages should
return.  This is unfortunate but fixing it properly would require a lot
of code duplication.

Fix the issue by introducing the requested migrate type argument and
special case MIGRATE_CMA case where CMA page blocks are handled
properly.  This will work for memory hotplug because it requires
MIGRATE_MOVABLE.

Link: http://lkml.kernel.org/r/20171019122118.y6cndierwl2vnguj@dhcp22.suse.czSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reported-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: NStefan Wahren <stefan.wahren@i2se.com>
Tested-by: NRan Wang <ran.wang_1@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

4da2ce25

mm: drop migrate type checks from has_unmovable_pages · d7b236e1

由 Michal Hocko 提交于 11月 15, 2017

Michael has noticed that the memory offline tries to migrate kernel code
pages when doing

 echo 0 > /sys/devices/system/memory/memory0/online

The current implementation will fail the operation after several failed
page migration attempts but we shouldn't even attempt to migrate that
memory and fail right away because this memory is clearly not
migrateable.  This will become a real problem when we drop the retry
loop counter resp.  timeout.

The real problem is in has_unmovable_pages in fact.  We should fail if
there are any non migrateable pages in the area.  In orther to guarantee
that remove the migrate type checks because MIGRATE_MOVABLE is not
guaranteed to contain only migrateable pages.  It is merely a heuristic.
Similarly MIGRATE_CMA does guarantee that the page allocator doesn't
allocate any non-migrateable pages from the block but CMA allocations
themselves are unlikely to migrateable.  Therefore remove both checks.

[akpm@linux-foundation.org: remove unused local `mt']
Link: http://lkml.kernel.org/r/20171013120013.698-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reported-by: NMichael Ellerman <mpe@ellerman.id.au>
Tested-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Tested-by: NTony Lindgren <tony@atomide.com>
Tested-by: NRan Wang <ran.wang_1@nxp.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

d7b236e1

mm/page-writeback.c: remove unused parameter from balance_dirty_pages() · 4c578dce

由 Tahsin Erdogan 提交于 11月 15, 2017

"mapping" parameter to balance_dirty_pages() is not used anymore.

Fixes: dfb8ae56 ("writeback: let balance_dirty_pages() work on the matching cgroup bdi_writeback")
Link: http://lkml.kernel.org/r/20170927221311.23263-1-tahsin@google.comSigned-off-by: NTahsin Erdogan <tahsin@google.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

4c578dce

mm, swap: fix false error message in __swp_swapcount() · e9a6effa

由 Huang Ying 提交于 11月 15, 2017

When a page fault occurs for a swap entry, the physical swap readahead
(not the VMA base swap readahead) may readahead several swap entries
after the fault swap entry.  The readahead algorithm calculates some of
the swap entries to readahead via increasing the offset of the fault
swap entry without checking whether they are beyond the end of the swap
device and it relys on the __swp_swapcount() and swapcache_prepare() to
check it.  Although __swp_swapcount() checks for the swap entry passed
in, it will complain with the error message as follow for the expected
invalid swap entry.  This may make the end users confused.

  swap_info_get: Bad swap offset entry 0200f8a7

To fix the false error message, the swap entry checking is added in
swapin_readahead() to avoid to pass the out-of-bound swap entries and
the swap entry reserved for the swap header to __swp_swapcount() and
swapcache_prepare().

Link: http://lkml.kernel.org/r/20171102054225.22897-1-ying.huang@intel.com
Fixes: e8c26ab6 ("mm/swap: skip readahead for unreferenced swap slots")
Signed-off-by: N"Huang, Ying" <ying.huang@intel.com>
Reported-by: NChristian Kujau <lists@nerdbynature.de>
Acked-by: NMinchan Kim <minchan@kernel.org>
Suggested-by: NMinchan Kim <minchan@kernel.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>	[4.11+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

e9a6effa

mm: swap: SWP_SYNCHRONOUS_IO: skip swapcache only if swapped page has no other reference · aa8d22a1