linux-toradex.git/include/linux/vmstat.h, branch v5.1-rc1

include/linux/vmstat.h: remove unused page state adjustment macro

2018-12-28T20:11:51+00:00

These four macro are not used anymore.

Just remove them.

Link: http://lkml.kernel.org/r/20181214063211.2290-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang 
Acked-by: Michal Hocko 
Reviewed-by: David Hildenbrand 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, vmscan, tracing: use pointer to reclaim_stat struct in trace event

2018-04-11T17:28:30+00:00

The trace event trace_mm_vmscan_lru_shrink_inactive() currently has 12
parameters! Seven of them are from the reclaim_stat structure.  This
structure is currently local to mm/vmscan.c.  By moving it to the global
vmstat.h header, we can also reference it from the vmscan tracepoints.
In moving it, it brings down the overhead of passing so many arguments
to the trace event.  In the future, we may limit the number of arguments
that a trace event may pass (ideally just 6, but more realistically it
may be 8).

Before this patch, the code to call the trace event is this:

 0f 83 aa fe ff ff       jae    ffffffff811e6261 
 48 8b 45 a0             mov    -0x60(%rbp),%rax
 45 8b 64 24 20          mov    0x20(%r12),%r12d
 44 8b 6d d4             mov    -0x2c(%rbp),%r13d
 8b 4d d0                mov    -0x30(%rbp),%ecx
 44 8b 75 cc             mov    -0x34(%rbp),%r14d
 44 8b 7d c8             mov    -0x38(%rbp),%r15d
 48 89 45 90             mov    %rax,-0x70(%rbp)
 8b 83 b8 fe ff ff       mov    -0x148(%rbx),%eax
 8b 55 c0                mov    -0x40(%rbp),%edx
 8b 7d c4                mov    -0x3c(%rbp),%edi
 8b 75 b8                mov    -0x48(%rbp),%esi
 89 45 80                mov    %eax,-0x80(%rbp)
 65 ff 05 e4 f7 e2 7e    incl   %gs:0x7ee2f7e4(%rip)        # 15bd0 <__preempt_count>
 48 8b 05 75 5b 13 01    mov    0x1135b75(%rip),%rax        # ffffffff8231bf68 <__tracepoint_mm_vmscan_lru_shrink_inactive+0x28>
 48 85 c0                test   %rax,%rax
 74 72                   je     ffffffff811e646a 
 48 89 c3                mov    %rax,%rbx
 4c 8b 10                mov    (%rax),%r10
 89 f8                   mov    %edi,%eax
 48 89 85 68 ff ff ff    mov    %rax,-0x98(%rbp)
 89 f0                   mov    %esi,%eax
 48 89 85 60 ff ff ff    mov    %rax,-0xa0(%rbp)
 89 c8                   mov    %ecx,%eax
 48 89 85 78 ff ff ff    mov    %rax,-0x88(%rbp)
 89 d0                   mov    %edx,%eax
 48 89 85 70 ff ff ff    mov    %rax,-0x90(%rbp)
 8b 45 8c                mov    -0x74(%rbp),%eax
 48 8b 7b 08             mov    0x8(%rbx),%rdi
 48 83 c3 18             add    $0x18,%rbx
 50                      push   %rax
 41 54                   push   %r12
 41 55                   push   %r13
 ff b5 78 ff ff ff       pushq  -0x88(%rbp)
 41 56                   push   %r14
 41 57                   push   %r15
 ff b5 70 ff ff ff       pushq  -0x90(%rbp)
 4c 8b 8d 68 ff ff ff    mov    -0x98(%rbp),%r9
 4c 8b 85 60 ff ff ff    mov    -0xa0(%rbp),%r8
 48 8b 4d 98             mov    -0x68(%rbp),%rcx
 48 8b 55 90             mov    -0x70(%rbp),%rdx
 8b 75 80                mov    -0x80(%rbp),%esi
 41 ff d2                callq  *%r10

After the patch:

 0f 83 a8 fe ff ff       jae    ffffffff811e626d 
 8b 9b b8 fe ff ff       mov    -0x148(%rbx),%ebx
 45 8b 64 24 20          mov    0x20(%r12),%r12d
 4c 8b 6d a0             mov    -0x60(%rbp),%r13
 65 ff 05 f5 f7 e2 7e    incl   %gs:0x7ee2f7f5(%rip)        # 15bd0 <__preempt_count>
 4c 8b 35 86 5b 13 01    mov    0x1135b86(%rip),%r14        # ffffffff8231bf68 <__tracepoint_mm_vmscan_lru_shrink_inactive+0x28>
 4d 85 f6                test   %r14,%r14
 74 2a                   je     ffffffff811e6411 
 49 8b 06                mov    (%r14),%rax
 8b 4d 8c                mov    -0x74(%rbp),%ecx
 49 8b 7e 08             mov    0x8(%r14),%rdi
 49 83 c6 18             add    $0x18,%r14
 4c 89 ea                mov    %r13,%rdx
 45 89 e1                mov    %r12d,%r9d
 4c 8d 45 b8             lea    -0x48(%rbp),%r8
 89 de                   mov    %ebx,%esi
 51                      push   %rcx
 48 8b 4d 98             mov    -0x68(%rbp),%rcx
 ff d0                   callq  *%rax

Link: http://lkml.kernel.org/r/2559d7cb-ec60-1200-2362-04fa34fd02bb@fb.com
Link: http://lkml.kernel.org/r/20180322121003.4177af15@gandalf.local.home
Signed-off-by: Steven Rostedt (VMware) 
Reported-by: Alexei Starovoitov 
Acked-by: David Rientjes 
Acked-by: Michal Hocko 
Cc: Mel Gorman 
Cc: Vlastimil Babka 
Cc: Andrey Ryabinin 
Cc: Alexei Starovoitov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove unused pgdat_reclaimable_pages()

2018-02-01T01:18:37+00:00

Remove unused function pgdat_reclaimable_pages() and
node_page_state_snapshot() which becomes unused as well.

Link: http://lkml.kernel.org/r/20171122094416.26019-1-jack@suse.cz
Signed-off-by: Jan Kara 
Acked-by: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, sysctl: make NUMA stats configurable

2017-11-16T02:21:07+00:00

This is the second step which introduces a tunable interface that allow
numa stats configurable for optimizing zone_statistics(), as suggested
by Dave Hansen and Ying Huang.

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

When page allocation performance becomes a bottleneck and you can
tolerate some possible tool breakage and decreased numa counter
precision, you can do:

	echo 0 > /proc/sys/vm/numa_stat

In this case, numa counter update is ignored.  We can see about
*4.8%*(185->176) drop of cpu cycles per single page allocation and
reclaim on Jesper's page_bench01 (single thread) and *8.1%*(343->315)
drop of cpu cycles per single page allocation and reclaim on Jesper's
page_bench03 (88 threads) running on a 2-Socket Broadwell-based server
(88 threads, 126G memory).

Benchmark link provided by Jesper D Brouer (increase loop times to
10000000):

  https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm/bench

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

When page allocation performance is not a bottleneck and you want all
tooling to work, you can do:

	echo 1 > /proc/sys/vm/numa_stat

This is system default setting.

Many thanks to Michal Hocko, Dave Hansen, Ying Huang and Vlastimil Babka
for comments to help improve the original patch.

[keescook@chromium.org: make sure mutex is a global static]
  Link: http://lkml.kernel.org/r/20171107213809.GA4314@beast
Link: http://lkml.kernel.org/r/1508290927-8518-1-git-send-email-kemi.wang@intel.com
Signed-off-by: Kemi Wang 
Signed-off-by: Kees Cook 
Reported-by: Jesper Dangaard Brouer 
Suggested-by: Dave Hansen 
Suggested-by: Ying Huang 
Acked-by: Vlastimil Babka 
Acked-by: Michal Hocko 
Cc: "Luis R . Rodriguez" 
Cc: Kees Cook 
Cc: Jonathan Corbet 
Cc: Mel Gorman 
Cc: Johannes Weiner 
Cc: Christopher Lameter 
Cc: Sebastian Andrzej Siewior 
Cc: Andrey Ryabinin 
Cc: Tim Chen 
Cc: Andi Kleen 
Cc: Aaron Lu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

mm: consider the number in local CPUs when reading NUMA stats

2017-09-09T01:26:47+00:00

To avoid deviation, the per cpu number of NUMA stats in
vm_numa_stat_diff[] is included when a user *reads* the NUMA stats.

Since NUMA stats does not be read by users frequently, and kernel does not
need it to make a decision, it will not be a problem to make the readers
more expensive.

Link: http://lkml.kernel.org/r/1503568801-21305-4-git-send-email-kemi.wang@intel.com
Signed-off-by: Kemi Wang 
Reported-by: Jesper Dangaard Brouer 
Acked-by: Mel Gorman 
Cc: Aaron Lu 
Cc: Andi Kleen 
Cc: Christopher Lameter 
Cc: Dave Hansen 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Tim Chen 
Cc: Ying Huang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: change the call sites of numa statistics items

2017-09-09T01:26:47+00:00

Patch series "Separate NUMA statistics from zone statistics", v2.

Each page allocation updates a set of per-zone statistics with a call to
zone_statistics().  As discussed in 2017 MM summit, these are a
substantial source of overhead in the page allocator and are very rarely
consumed.  This significant overhead in cache bouncing caused by zone
counters (NUMA associated counters) update in parallel in multi-threaded
page allocation (pointed out by Dave Hansen).

A link to the MM summit slides:
  http://people.netfilter.org/hawk/presentations/MM-summit2017/MM-summit2017-JesperBrouer.pdf

To mitigate this overhead, this patchset separates NUMA statistics from
zone statistics framework, and update NUMA counter threshold to a fixed
size of MAX_U16 - 2, as a small threshold greatly increases the update
frequency of the global counter from local per cpu counter (suggested by
Ying Huang).  The rationality is that these statistics counters don't
need to be read often, unlike other VM counters, so it's not a problem
to use a large threshold and make readers more expensive.

With this patchset, we see 31.3% drop of CPU cycles(537-->369, see
below) for per single page allocation and reclaim on Jesper's
page_bench03 benchmark.  Meanwhile, this patchset keeps the same style
of virtual memory statistics with little end-user-visible effects (only
move the numa stats to show behind zone page stats, see the first patch
for details).

I did an experiment of single page allocation and reclaim concurrently
using Jesper's page_bench03 benchmark on a 2-Socket Broadwell-based
server (88 processors with 126G memory) with different size of threshold
of pcp counter.

Benchmark provided by Jesper D Brouer(increase loop times to 10000000):
  https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm/bench

   Threshold   CPU cycles    Throughput(88 threads)
      32        799         241760478
      64        640         301628829
      125       537         358906028 <==> system by default
      256       468         412397590
      512       428         450550704
      4096      399         482520943
      20000     394         489009617
      30000     395         488017817
      65533     369(-31.3%) 521661345(+45.3%) <==> with this patchset
      N/A       342(-36.3%) 562900157(+56.8%) <==> disable zone_statistics

This patch (of 3):

In this patch, NUMA statistics is separated from zone statistics
framework, all the call sites of NUMA stats are changed to use
numa-stats-specific functions, it does not have any functionality change
except that the number of NUMA stats is shown behind zone page stats
when users *read* the zone info.

E.g. cat /proc/zoneinfo
    ***Base***                           ***With this patch***
nr_free_pages 3976                         nr_free_pages 3976
nr_zone_inactive_anon 0                    nr_zone_inactive_anon 0
nr_zone_active_anon 0                      nr_zone_active_anon 0
nr_zone_inactive_file 0                    nr_zone_inactive_file 0
nr_zone_active_file 0                      nr_zone_active_file 0
nr_zone_unevictable 0                      nr_zone_unevictable 0
nr_zone_write_pending 0                    nr_zone_write_pending 0
nr_mlock     0                             nr_mlock     0
nr_page_table_pages 0                      nr_page_table_pages 0
nr_kernel_stack 0                          nr_kernel_stack 0
nr_bounce    0                             nr_bounce    0
nr_zspages   0                             nr_zspages   0
numa_hit 0                                *nr_free_cma  0*
numa_miss 0                                numa_hit     0
numa_foreign 0                             numa_miss    0
numa_interleave 0                          numa_foreign 0
numa_local   0                             numa_interleave 0
numa_other   0                             numa_local   0
*nr_free_cma 0*                            numa_other 0
    ...                                        ...
vm stats threshold: 10                     vm stats threshold: 10
    ...                                        ...

The next patch updates the numa stats counter size and threshold.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1503568801-21305-2-git-send-email-kemi.wang@intel.com
Signed-off-by: Kemi Wang 
Reported-by: Jesper Dangaard Brouer 
Acked-by: Mel Gorman 
Cc: Michal Hocko 
Cc: Johannes Weiner 
Cc: Christopher Lameter 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: Ying Huang 
Cc: Aaron Lu 
Cc: Tim Chen 
Cc: Dave Hansen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: rename global_page_state to global_zone_page_state

2017-09-07T00:27:29+00:00

global_page_state is error prone as a recent bug report pointed out [1].
It only returns proper values for zone based counters as the enum it
gets suggests.  We already have global_node_page_state so let's rename
global_page_state to global_zone_page_state to be more explicit here.
All existing users seems to be correct:

$ git grep "global_page_state(NR_" | sed 's@.*(\(NR_[A-Z_]*\)).*@\1@' | sort | uniq -c
      2 NR_BOUNCE
      2 NR_FREE_CMA_PAGES
     11 NR_FREE_PAGES
      1 NR_KERNEL_STACK_KB
      1 NR_MLOCK
      2 NR_PAGETABLE

This patch shouldn't introduce any functional change.

[1] http://lkml.kernel.org/r/201707260628.v6Q6SmaS030814@www262.sakura.ne.jp

Link: http://lkml.kernel.org/r/20170801134256.5400-2-hannes@cmpxchg.org
Signed-off-by: Michal Hocko 
Signed-off-by: Johannes Weiner 
Cc: Tetsuo Handa 
Cc: Josef Bacik 
Cc: Vladimir Davydov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcontrol: per-lruvec stats infrastructure

2017-07-06T23:24:35+00:00

lruvecs are at the intersection of the NUMA node and memcg, which is the
scope for most paging activity.

Introduce a convenient accounting infrastructure that maintains
statistics per node, per memcg, and the lruvec itself.

Then convert over accounting sites for statistics that are already
tracked in both nodes and memcgs and can be easily switched.

[hannes@cmpxchg.org: fix crash in the new cgroup stat keeping code]
  Link: http://lkml.kernel.org/r/20170531171450.GA10481@cmpxchg.org
[hannes@cmpxchg.org: don't track uncharged pages at all
  Link: http://lkml.kernel.org/r/20170605175254.GA8547@cmpxchg.org
[hannes@cmpxchg.org: add missing free_percpu()]
  Link: http://lkml.kernel.org/r/20170605175354.GB8547@cmpxchg.org
[linux@roeck-us.net: hexagon: fix build error caused by include file order]
  Link: http://lkml.kernel.org/r/20170617153721.GA4382@roeck-us.net
Link: http://lkml.kernel.org/r/20170530181724.27197-6-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner 
Signed-off-by: Guenter Roeck 
Acked-by: Vladimir Davydov 
Cc: Josef Bacik 
Cc: Michal Hocko 
Cc: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: vmstat: replace __count_zone_vm_events with a zone id equivalent

2016-07-28T23:07:41+00:00

This is partially a preparation patch for more vmstat work but it also
has the slight advantage that __count_zid_vm_events is cheaper to
calculate than __count_zone_vm_events().

Link: http://lkml.kernel.org/r/1467970510-21195-32-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman 
Acked-by: Vlastimil Babka 
Cc: Hillf Danton 
Acked-by: Johannes Weiner 
Cc: Joonsoo Kim 
Cc: Michal Hocko 
Cc: Minchan Kim 
Cc: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds