22 Feb, 2018
1 commit
-
commit d8be75663cec0069b85f80191abd2682ce4a512f upstream.
Now that kmemcheck is gone, we don't need the NOTRACK flags.
Link: http://lkml.kernel.org/r/20171007030159.22241-5-alexander.levin@verizon.com
Signed-off-by: Sasha Levin
Cc: Alexander Potapenko
Cc: Eric W. Biederman
Cc: Michal Hocko
Cc: Pekka Enberg
Cc: Steven Rostedt
Cc: Tim Hansen
Cc: Vegard Nossum
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Greg Kroah-Hartman
02 Nov, 2017
1 commit
-
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
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
14 Sep, 2017
1 commit
-
GFP_TEMPORARY was introduced by commit e12ba74d8ff3 ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE. It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation. As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag. How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory. So
this is rather misleading and hard to evaluate for any benefits.I have checked some random users and none of them has added the flag
with a specific justification. I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring. This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse. Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL. Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic. It
seems to be a heuristic without any measured advantage for most (if not
all) its current users. The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers. So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org
[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko
Signed-off-by: Stephen Rothwell
Acked-by: Mel Gorman
Acked-by: Vlastimil Babka
Cc: Matthew Wilcox
Cc: Neil Brown
Cc: "Theodore Ts'o"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Jul, 2017
1 commit
-
__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to
the page allocator. This has been true but only for allocations
requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always
ignored for smaller sizes. This is a bit unfortunate because there is
no way to express the same semantic for those requests and they are
considered too important to fail so they might end up looping in the
page allocator for ever, similarly to GFP_NOFAIL requests.Now that the whole tree has been cleaned up and accidental or misled
usage of __GFP_REPEAT flag has been removed for !costly requests we can
give the original flag a better name and more importantly a more useful
semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user
that the allocator would try really hard but there is no promise of a
success. This will work independent of the order and overrides the
default allocator behavior. Page allocator users have several levels of
guarantee vs. cost options (take GFP_KERNEL as an example)- GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_
attempt to free memory at all. The most light weight mode which even
doesn't kick the background reclaim. Should be used carefully because
it might deplete the memory and the next user might hit the more
aggressive reclaim- GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic
allocation without any attempt to free memory from the current
context but can wake kswapd to reclaim memory if the zone is below
the low watermark. Can be used from either atomic contexts or when
the request is a performance optimization and there is another
fallback for a slow path.- (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) -
non sleeping allocation with an expensive fallback so it can access
some portion of memory reserves. Usually used from interrupt/bh
context with an expensive slow path fallback.- GFP_KERNEL - both background and direct reclaim are allowed and the
_default_ page allocator behavior is used. That means that !costly
allocation requests are basically nofail but there is no guarantee of
that behavior so failures have to be checked properly by callers
(e.g. OOM killer victim is allowed to fail currently).- GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior
and all allocation requests fail early rather than cause disruptive
reclaim (one round of reclaim in this implementation). The OOM killer
is not invoked.- GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator
behavior and all allocation requests try really hard. The request
will fail if the reclaim cannot make any progress. The OOM killer
won't be triggered.- GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior
and all allocation requests will loop endlessly until they succeed.
This might be really dangerous especially for larger orders.Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL
because they already had their semantic. No new users are added.
__alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if
there is no progress and we have already passed the OOM point.This means that all the reclaim opportunities have been exhausted except
the most disruptive one (the OOM killer) and a user defined fallback
behavior is more sensible than keep retrying in the page allocator.[akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c]
[mhocko@suse.com: semantic fix]
Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz
[mhocko@kernel.org: address other thing spotted by Vlastimil]
Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org
Signed-off-by: Michal Hocko
Acked-by: Vlastimil Babka
Cc: Alex Belits
Cc: Chris Wilson
Cc: Christoph Hellwig
Cc: Darrick J. Wong
Cc: David Daney
Cc: Johannes Weiner
Cc: Mel Gorman
Cc: NeilBrown
Cc: Ralf Baechle
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jun, 2017
1 commit
-
To consolidate the error reporting facility.
Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-b41iot1094katoffdf19w9zk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
20 Apr, 2017
4 commits
-
Removing it from util.h, part of an effort to disentangle the includes
hell, that makes changes to util.h or something included by it to cause
a complete rebuild of the tools.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-ztrjy52q1rqcchuy3rubfgt2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo -
More stuff that came from git, out of the hodge-podge that is util.h
Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-e3lana4gctz3ub4hn4y29hkw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo -
Needed to use the PRI[xu](32,64) formatting macros.
Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-wkbho8kaw24q67dd11q0j39f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo -
To pave the way for further cleanups where linux/kernel.h may stop being
included in some header.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-qqxan6tfsl6qx3l0v3nwgjvk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
27 Mar, 2017
1 commit
-
We got it from the git sources but never used it for anything, with the
place where this would be somehow used remaining:static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
{
prefix = NULL;
if (p->option & RUN_SETUP)
prefix = NULL; /* setup_perf_directory(); */Ditch it.
Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-uw5swz05vol0qpr32c5lpvus@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
14 Mar, 2017
1 commit
-
Introduce a new option to record PERF_RECORD_NAMESPACES events emitted
by the kernel when fork, clone, setns or unshare are invoked. And update
perf-record documentation with the new option to record namespace
events.Committer notes:
Combined it with a later patch to allow printing it via 'perf report -D'
and be able to test the feature introduced in this patch. Had to move
here also perf_ns__name(), that was introduced in another later patch.Also used PRIu64 and PRIx64 to fix the build in some enfironments wrt:
util/event.c:1129:39: error: format '%lx' expects argument of type 'long unsigned int', but argument 6 has type 'long long unsigned int' [-Werror=format=]
ret += fprintf(fp, "%u/%s: %lu/0x%lx%s", idx
^
Testing it:# perf record --namespaces -a
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.083 MB perf.data (423 samples) ]
#
# perf report -D
3 2028902078892 0x115140 [0xa0]: PERF_RECORD_NAMESPACES 14783/14783 - nr_namespaces: 7
[0/net: 3/0xf0000081, 1/uts: 3/0xeffffffe, 2/ipc: 3/0xefffffff, 3/pid: 3/0xeffffffc,
4/user: 3/0xeffffffd, 5/mnt: 3/0xf0000000, 6/cgroup: 3/0xeffffffb]0x1151e0 [0x30]: event: 9
.
. ... raw event: size 48 bytes
. 0000: 09 00 00 00 02 00 30 00 c4 71 82 68 0c 7f 00 00 ......0..q.h....
. 0010: a9 39 00 00 a9 39 00 00 94 28 fe 63 d8 01 00 00 .9...9...(.c....
. 0020: 03 00 00 00 00 00 00 00 ce c4 02 00 00 00 00 00 ................
NAMESPACES events: 1
#Signed-off-by: Hari Bathini
Acked-by: Jiri Olsa
Tested-by: Arnaldo Carvalho de Melo
Cc: Alexander Shishkin
Cc: Alexei Starovoitov
Cc: Ananth N Mavinakayanahalli
Cc: Aravinda Prasad
Cc: Brendan Gregg
Cc: Daniel Borkmann
Cc: Eric Biederman
Cc: Peter Zijlstra
Cc: Sargun Dhillon
Cc: Steven Rostedt
Link: http://lkml.kernel.org/r/148891930386.25309.18412039920746995488.stgit@hbathini.in.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo
14 Feb, 2017
1 commit
-
As it is an array, so will always evaluate to 'true', as reported by
clang:builtin-sched.c:2070:19: error: address of array 'sym->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
if (sym && sym->name) {
~~ ~~~~~^~~~
1 warning generated.So just ditch all those useless checks.
Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-ydpm927col06paixb775jjx5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
27 Jan, 2017
1 commit
-
Previously these were being ignored, sometimes silently.
Stop doing that, emitting debug messages and handling the errors.
Testing it:
$ cat ~/.perfconfig
cat: /home/acme/.perfconfig: No such file or directory
$ perf stat -e cycles usleep 1Performance counter stats for 'usleep 1':
938,996 cycles:u
0.003813731 seconds time elapsed
$ perf top --stdio
Error:
You may not have permission to collect system-wide stats.Consider tweaking /proc/sys/kernel/perf_event_paranoid,
[ perf record: Captured and wrote 0.019 MB perf.data (7 samples) ]
[acme@jouet linux]$ perf report --stdio
# To display the perf.data header info, please use --header/--header-only options.
# Overhead Command Shared Object Symbol
# ........ ....... ................. .........................
71.77% usleep libc-2.24.so [.] _dl_addr
27.07% usleep ld-2.24.so [.] _dl_next_ld_env_entry
1.13% usleep [kernel.kallsyms] [k] page_fault
$
$ touch ~/.perfconfig
$ ls -la ~/.perfconfig
-rw-rw-r--. 1 acme acme 0 Jan 27 12:14 /home/acme/.perfconfig
$
$ perf stat -e instructions usleep 1Performance counter stats for 'usleep 1':
244,610 instructions:u
0.000805383 seconds time elapsed
$
[root@jouet ~]# chown acme.acme ~/.perfconfig
[root@jouet ~]# perf stat -e cycles usleep 1
Warning: File /root/.perfconfig not owned by current user or root, ignoring it.Performance counter stats for 'usleep 1':
937,615 cycles
0.000836931 seconds time elapsed
#Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-j2rq96so6xdqlr8p8rd6a3jx@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
11 Jan, 2017
1 commit
-
The flag was introduced by commit 78afd5612deb ("mm: add
__GFP_OTHER_NODE flag") to allow proper accounting of remote node
allocations done by kernel daemons on behalf of a process - e.g.
khugepaged.After "mm: fix remote numa hits statistics" we do not need and actually
use the flag so we can safely remove it because all allocations which
are satisfied from their "home" node are accounted properly.[mhocko@suse.com: fix build]
Link: http://lkml.kernel.org/r/20170106122225.GK5556@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170102153057.9451-3-mhocko@kernel.org
Signed-off-by: Michal Hocko
Acked-by: Mel Gorman
Acked-by: Vlastimil Babka
Cc: Michal Hocko
Cc: Johannes Weiner
Cc: Joonsoo Kim
Cc: Taku Izumi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Dec, 2016
1 commit
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Add option to allow user to control analysis window. e.g., collect data
for time window and analyze a segment of interest within that window.Committer notes:
Testing it:
# perf kmem record usleep 1
[ perf record: Woken up 0 times to write data ]
[ perf record: Captured and wrote 1.540 MB perf.data (2049 samples) ]
# perf evlist
kmem:kmalloc
kmem:kmalloc_node
kmem:kfree
kmem:kmem_cache_alloc
kmem:kmem_cache_alloc_node
kmem:kmem_cache_free
# Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events
#
# # Use 'perf script' to get a first approach, select a chunk for then using
# # with 'perf kmem stat --time'
#
# perf script | tail -15
usleep 9889 [0] 20119.782088: kmem:kmem_cache_free: (selinux_file_free_security+0x27) call_site=ffffffffb936aa07 ptr=0xffff888a1df49fc0
perf 9888 [3] 20119.782088: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0
perf 9888 [3] 20119.782089: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO
perf 9888 [3] 20119.782090: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0
perf 9888 [3] 20119.782090: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO
usleep 9889 [0] 20119.782091: kmem:kmem_cache_alloc: (__sigqueue_alloc+0x4a) call_site=ffffffffb90ad33a ptr=0xffff8889f071f6e0 bytes_req=160 bytes_alloc=160 gfp_flags=GFP_ATOMIC|__GFP_NOTRACK
perf 9888 [3] 20119.782091: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0
perf 9888 [3] 20119.782093: kmem:kmem_cache_free: (__sigqueue_free.part.17+0x33) call_site=ffffffffb90ad3f3 ptr=0xffff8889f071f6e0
perf 9888 [3] 20119.782098: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO
perf 9888 [3] 20119.782098: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0
perf 9888 [3] 20119.782099: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO
perf 9888 [3] 20119.782100: kmem:kmem_cache_alloc: (alloc_buffer_head+0x21) call_site=ffffffffb9287cc1 ptr=0xffff8889b12722d8 bytes_req=104 bytes_alloc=104 gfp_flags=GFP_NOFS|__GFP_ZERO
perf 9888 [3] 20119.782101: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0
perf 9888 [3] 20119.782102: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO
perf 9888 [3] 20119.782103: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0
#
# # stats for the whole perf.data file, i.e. no interval specified
#
# perf kmem statSUMMARY (SLAB allocator)
========================
Total bytes requested: 172,628
Total bytes allocated: 173,088
Total bytes freed: 161,280
Net total bytes allocated: 11,808
Total bytes wasted on internal fragmentation: 460
Internal fragmentation: 0.265761%
Cross CPU allocations: 0/851
#
# # stats for an end open interval, after a certain time:
#
# perf kmem stat --time 20119.782088,SUMMARY (SLAB allocator)
========================
Total bytes requested: 552
Total bytes allocated: 552
Total bytes freed: 448
Net total bytes allocated: 104
Total bytes wasted on internal fragmentation: 0
Internal fragmentation: 0.000000%
Cross CPU allocations: 0/8
#Signed-off-by: David Ahern
Tested-by: Arnaldo Carvalho de Melo
Acked-by: Namhyung Kim
Cc: Jiri Olsa
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/1480439746-42695-6-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo
29 Nov, 2016
1 commit
-
Track freed memory as well as allocations and show the net in the
summary.Committer notes:
Testing it:
# perf kmem record usleep 1
[ perf record: Woken up 0 times to write data ]
[ perf record: Captured and wrote 1.626 MB perf.data (4208 samples) ]
[root@jouet ~]# perf kmem stat --slabSUMMARY (SLAB allocator)
========================
Total bytes requested: 234,011
Total bytes allocated: 234,504
Total bytes freed: 213,328
Tested-by: Arnaldo Carvalho de Melo
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/1480110133-37039-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo
05 Sep, 2016
1 commit
-
We're not using it anymore, few users were, but we really could do
without it, simplify lots of functions by removing it.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Masami Hiramatsu
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-1zng8wdznn00iiz08bb7q3vn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
29 Jul, 2016
1 commit
-
After the previous patch, we can distinguish costly allocations that
should be really lightweight, such as THP page faults, with
__GFP_NORETRY. This means we don't need to recognize khugepaged
allocations via PF_KTHREAD anymore. We can also change THP page faults
in areas where madvise(MADV_HUGEPAGE) was used to try as hard as
khugepaged, as the process has indicated that it benefits from THP's and
is willing to pay some initial latency costs.We can also make the flags handling less cryptic by distinguishing
GFP_TRANSHUGE_LIGHT (no reclaim at all, default mode in page fault) from
GFP_TRANSHUGE (only direct reclaim, khugepaged default). Adding
__GFP_NORETRY or __GFP_KSWAPD_RECLAIM is done where needed.The patch effectively changes the current GFP_TRANSHUGE users as
follows:* get_huge_zero_page() - the zero page lifetime should be relatively
long and it's shared by multiple users, so it's worth spending some
effort on it. We use GFP_TRANSHUGE, and __GFP_NORETRY is not added.
This also restores direct reclaim to this allocation, which was
unintentionally removed by commit e4a49efe4e7e ("mm: thp: set THP defrag
by default to madvise and add a stall-free defrag option")* alloc_hugepage_khugepaged_gfpmask() - this is khugepaged, so latency
is not an issue. So if khugepaged "defrag" is enabled (the default), do
reclaim via GFP_TRANSHUGE without __GFP_NORETRY. We can remove the
PF_KTHREAD check from page alloc.As a side-effect, khugepaged will now no longer check if the initial
compaction was deferred or contended. This is OK, as khugepaged sleep
times between collapsion attempts are long enough to prevent noticeable
disruption, so we should allow it to spend some effort.* migrate_misplaced_transhuge_page() - already was masking out
__GFP_RECLAIM, so just convert to GFP_TRANSHUGE_LIGHT which is
equivalent.* alloc_hugepage_direct_gfpmask() - vma's with VM_HUGEPAGE (via madvise)
are now allocating without __GFP_NORETRY. Other vma's keep using
__GFP_NORETRY if direct reclaim/compaction is at all allowed (by default
it's allowed only for madvised vma's). The rest is conversion to
GFP_TRANSHUGE(_LIGHT).[mhocko@suse.com: suggested GFP_TRANSHUGE_LIGHT]
Link: http://lkml.kernel.org/r/20160721073614.24395-7-vbabka@suse.cz
Signed-off-by: Vlastimil Babka
Acked-by: Michal Hocko
Acked-by: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Jun, 2016
2 commits
-
To match the semantics for list.h in the kernel, that are used to
implement those macros.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Milian Wolff
Cc: Namhyung Kim
Cc: Taeung Song
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-qbcjlgj0ffxquxscahbpddi3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo -
Lately util/config.h has been added but util/cache.h has declarations of
functions and a global variable for config features.To manage codes about configuration at one spot, move them to
util/config.h and let source files that need config features include
config.h And if the source files that included previous cache.h need
only config.h, remove including cache.h.Signed-off-by: Taeung Song
Cc: Alexander Shishkin
Cc: Jiri Olsa
Cc: Masami Hiramatsu
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: Wang Nan
Link: http://lkml.kernel.org/r/1466672119-4852-2-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo
15 Apr, 2016
1 commit
-
The recent perf_evsel__fprintf_callchain() move to evsel.c added several
new symbol requirements to the python binding, for instance:# perf test -v python
16: Try 'import perf' in python, checking link problems :
--- start ---
test child forked, pid 18030
Traceback (most recent call last):
File "", line 1, in
ImportError: /tmp/build/perf/python/perf.so: undefined symbol:
callchain_cursor
test child finished with -1
---- end ----
Try 'import perf' in python, checking link problems: FAILED!
#This would require linking against callchain.c to access to the global
callchain_cursor variables.Since lots of functions already receive as a parameter a
callchain_cursor struct pointer, make that be the case for some more
function so that we can start phasing out usage of yet another global
variable.Cc: Adrian Hunter
Cc: David Ahern
Cc: Frederic Weisbecker
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-djko3097eyg2rn66v2qcqfvn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
16 Mar, 2016
2 commits
-
In tracepoints, it's possible to print gfp flags in a human-friendly
format through a macro show_gfp_flags(), which defines a translation
array and passes is to __print_flags(). Since the following patch will
introduce support for gfp flags printing in printk(), it would be nice
to reuse the array. This is not straightforward, since __print_flags()
can't simply reference an array defined in a .c file such as mm/debug.c
- it has to be a macro to allow the macro magic to communicate the
format to userspace tools such as trace-cmd.The solution is to create a macro __def_gfpflag_names which is used both
in show_gfp_flags(), and to define the gfpflag_names[] array in
mm/debug.c.On the other hand, mm/debug.c also defines translation tables for page
flags and vma flags, and desire was expressed (but not implemented in
this series) to use these also from tracepoints. Thus, this patch also
renames the events/gfpflags.h file to events/mmflags.h and moves the
table definitions there, using the same macro approach as for gfpflags.
This allows translating all three kinds of mm-specific flags both in
tracepoints and printk.Signed-off-by: Vlastimil Babka
Reviewed-by: Michal Hocko
Cc: Steven Rostedt
Cc: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Ingo Molnar
Cc: Rasmus Villemoes
Cc: Joonsoo Kim
Cc: Minchan Kim
Cc: Sasha Levin
Cc: "Kirill A. Shutemov"
Cc: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When updating tracing's show_gfp_flags() I have noticed that perf's
gfp_compact_table is also outdated. Fill in the missing flags and place
a note in gfp.h to increase chance that future updates are synced.
Convert the __GFP_X flags from "GFP_X" to "__GFP_X" strings in line with
the previous patch.Signed-off-by: Vlastimil Babka
Acked-by: David Rientjes
Cc: Steven Rostedt
Cc: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Ingo Molnar
Cc: Rasmus Villemoes
Cc: Joonsoo Kim
Cc: Minchan Kim
Cc: Sasha Levin
Cc: "Kirill A. Shutemov"
Cc: Mel Gorman
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Feb, 2016
1 commit
-
Before this patch each subcommand calls perf_config() by themself,
reading the default configuration together with subcommand specific
options. If a subcommand doesn't have it own options, it needs to call
'perf_config(perf_default_config, NULL)' to ensure .perfconfig is
loaded.This patch brings perf_config(perf_default_config, NULL) to the very
start of main(), so subcommands don't need to do it.After this patch, 'llvm.clang-path' works for 'perf trace'.
Signed-off-by: Wang Nan
Suggested-and-Tested-by: Arnaldo Carvalho de Melo
Cc: Alexei Starovoitov
Cc: Jiri Olsa
Cc: Li Zefan
Cc: Masami Hiramatsu
Cc: Namhyung Kim
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1456479154-136027-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo
18 Dec, 2015
1 commit
-
Move the subcommand-related files from perf to a new library named
libsubcmd.a.Since we're moving files anyway, go ahead and rename 'exec_cmd.*' to
'exec-cmd.*' to be consistent with the naming of all the other files.Signed-off-by: Josh Poimboeuf
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/c0a838d4c878ab17fee50998811612b2281355c1.1450193761.git.jpoimboe@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo
01 Oct, 2015
2 commits
-
And it is also a step in the direction of killing the separation of data
and text maps in map_groups.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-rrds86kb3wx5wk8v38v56gw8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo -
In places where we were using its open coded equivalent.
Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-khkdugcdoqy3tkszm3jdxgbe@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
02 Jul, 2015
1 commit
-
When an error occurs an error value is just returned without freeing the
session. So allocating and freeing session have to be matched as a pair
even if an error occurs.Signed-off-by: Taeung Song
Acked-by: Jiri Olsa
Cc: Namhyung Kim
Link: http://lkml.kernel.org/r/1435652124-22414-3-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo
29 May, 2015
1 commit
-
The last argument to strtok_r doesn't need to be initialized, its just a
placeholder to make this routine reentrant, but gcc doesn't know about
that and complains, breaking the build, fix it by setting it to NULL.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Link: http://lkml.kernel.org/n/tip-8e8rgbg3aom9uarsyqjrsctg@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
12 May, 2015
1 commit
-
The last argument to strtok_r doesn't need to be initialized, its just a
placeholder to make this routine reentrant, but gcc doesn't know about
that and complains, breaking the build, fix it by setting it to NULL.Fixes: 0e11115644b3 ("perf kmem: Print gfp flags in human readable string")
Cc: Adrian Hunter
Cc: Borislav Petkov
Cc: David Ahern
Cc: Don Zickus
Cc: Frederic Weisbecker
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Stephane Eranian
Link: http://lkml.kernel.org/n/tip-iyyvkbnkrd9g19f6ta9zfkem@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
11 May, 2015
1 commit
-
Conflicts:
tools/perf/builtin-kmem.cSigned-off-by: Ingo Molnar
09 May, 2015
1 commit
-
In addition to using refcounts for the struct thread lifetime
management, we need to protect access to machine->threads from
concurrent access.That happens in 'perf top', where a thread processes events, inserting
and deleting entries from that rb_tree while another thread decays
hist_entries, that end up dropping references and ultimately deleting
threads from the rb_tree and releasing its resources when no further
hist_entry (or other data structures, like in 'perf sched') references
it.So the rule is the same for refcounts + protected trees in the kernel,
get the tree lock, find object, bump the refcount, drop the tree lock,
return, use object, drop the refcount if no more use of it is needed,
keep it if storing it in some other data structure, drop when releasing
that data structure.I.e. pair "t = machine__find(new)_thread()" with a "thread__put(t)", and
"perf_event__preprocess_sample(&al)" with "addr_location__put(&al)".The addr_location__put() one is because as we return references to
several data structures, we may end up adding more reference counting
for the other data structures and then we'll drop it at
addr_location__put() time.Acked-by: David Ahern
Cc: Adrian Hunter
Cc: Borislav Petkov
Cc: Don Zickus
Cc: Frederic Weisbecker
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Stephane Eranian
Link: http://lkml.kernel.org/n/tip-bs9rt4n0jw3hi9f3zxyy3xln@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
06 May, 2015
1 commit
-
Sometimes one can mistakenly run 'perf kmem stat' without running 'perf
kmem record' before or with a different configuration like recording
--slab and stat --page. Show a warning message like the one below to
inform the user:# perf kmem stat --page --caller
No page allocation events found. Have you run 'perf kmem record --page'?Signed-off-by: Namhyung Kim
Acked-by: Pekka Enberg
Cc: David Ahern
Cc: Jiri Olsa
Cc: Joonsoo Kim
Cc: Minchan Kim
Cc: Peter Zijlstra
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1430837572-31395-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
05 May, 2015
4 commits
-
Currently perf kmem command will select --slab if neither --slab nor
--page is given for backward compatibility. Add kmem.default config
option to select the default value ('page' or 'slab').# cat ~/.perfconfig
[kmem]
default = page# perf kmem stat
SUMMARY (page allocator)
========================
Total allocation requests : 1,518 [ 6,096 KB ]
Total free requests : 1,431 [ 5,748 KB ]Total alloc+freed requests : 1,330 [ 5,344 KB ]
Total alloc-only requests : 188 [ 752 KB ]
Total free-only requests : 101 [ 404 KB ]Total allocation failures : 0 [ 0 KB ]
...Signed-off-by: Namhyung Kim
Acked-by: Pekka Enberg
Cc: David Ahern
Cc: Jiri Olsa
Cc: Joonsoo Kim
Cc: Minchan Kim
Cc: Peter Zijlstra
Cc: Taeung Song
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1429592107-1807-6-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo -
Save libtraceevent output and print it in the header.
# perf kmem stat --page --caller
#
# GFP flags
# ---------
# 00000010: NI: GFP_NOIO
# 000000d0: K: GFP_KERNEL
# 00000200: NWR: GFP_NOWARN
# 000084d0: K|R|Z: GFP_KERNEL|GFP_REPEAT|GFP_ZERO
# 000200d2: HU: GFP_HIGHUSER
# 000200da: HUM: GFP_HIGHUSER_MOVABLE
# 000280da: HUM|Z: GFP_HIGHUSER_MOVABLE|GFP_ZERO
# 002084d0: K|R|Z|NT: GFP_KERNEL|GFP_REPEAT|GFP_ZERO|GFP_NOTRACK
# 0102005a: NF|HW|M: GFP_NOFS|GFP_HARDWALL|GFP_MOVABLE---------------------------------------------------------------------------------------------------------
Total alloc (KB) | Hits | Order | Mig.type | GFP flags | Callsite
---------------------------------------------------------------------------------------------------------
60 | 15 | 0 | UNMOVABL | K|R|Z|NT | pte_alloc_one
40 | 10 | 0 | MOVABLE | HUM|Z | handle_mm_fault
24 | 6 | 0 | MOVABLE | HUM | do_wp_page
24 | 6 | 0 | UNMOVABL | K | __pollwait
...Requested-by: Joonsoo Kim
Suggested-by: Minchan Kim
Signed-off-by: Namhyung Kim
Acked-by: Pekka Enberg
Tested-by: Arnaldo Carvalho de Melo
Cc: David Ahern
Cc: Joonsoo Kim
Cc: Minchan Kim
Cc: Peter Zijlstra
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1429592107-1807-5-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo -
Currently 'perf kmem stat --page' shows total (page) allocation stat by
default, but sometimes one might want to see live (total alloc-only)
requests/pages only. The new --live option does this by subtracting freed
allocation from the stat.E.g.:
# perf kmem stat --page
SUMMARY (page allocator)
========================
Total allocation requests : 988,858 [ 4,045,368 KB ]
Total free requests : 886,484 [ 3,624,996 KB ]Total alloc+freed requests : 885,969 [ 3,622,628 KB ]
Total alloc-only requests : 102,889 [ 422,740 KB ]
Total free-only requests : 515 [ 2,368 KB ]Total allocation failures : 0 [ 0 KB ]
Order Unmovable Reclaimable Movable Reserved CMA/Isolated
----- ------------ ------------ ------------ ------------ ------------
0 172,173 3,083 806,686 . .
1 284 . . . .
2 6,124 58 . . .
3 114 335 . . .
4 . . . . .
5 . . . . .
6 . . . . .
7 . . . . .
8 . . . . .
9 . . 1 . .
10 . . . . .
# perf kmem stat --page --liveSUMMARY (page allocator)
========================
Total allocation requests : 988,858 [ 4,045,368 KB ]
Total free requests : 886,484 [ 3,624,996 KB ]Total alloc+freed requests : 885,969 [ 3,622,628 KB ]
Total alloc-only requests : 102,889 [ 422,740 KB ]
Total free-only requests : 515 [ 2,368 KB ]Total allocation failures : 0 [ 0 KB ]
Order Unmovable Reclaimable Movable Reserved CMA/Isolated
----- ------------ ------------ ------------ ------------ ------------
0 2,214 3,025 97,156 . .
1 59 . . . .
2 19 58 . . .
3 23 335 . . .
4 . . . . .
5 . . . . .
6 . . . . .
7 . . . . .
8 . . . . .
9 . . . . .
10 . . . . .
#Signed-off-by: Namhyung Kim
Acked-by: Pekka Enberg
Tested-by: Arnaldo Carvalho de Melo
Cc: David Ahern
Cc: Jiri Olsa
Cc: Joonsoo Kim
Cc: Minchan Kim
Cc: Peter Zijlstra
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1429592107-1807-4-git-send-email-namhyung@kernel.org
[ Added examples to the changeset log ]
Signed-off-by: Arnaldo Carvalho de Melo -
Add new sort keys for page: page, order, migtype, gfp - existing
'bytes', 'hit' and 'callsite' sort keys also work for page. Note that
-s/--sort option should be preceded by either of --slab or --page option
to determine where the sort keys applies.Now it properly groups and sorts allocation stats - so same
page/caller with different order/migtype/gfp will be printed on a
different line.# perf kmem stat --page --caller -l 10 -s order,hit
-----------------------------------------------------------------------------
Total alloc (KB) | Hits | Order | Mig.type | GFP flags | Callsite
-----------------------------------------------------------------------------
64 | 4 | 2 | RECLAIM | 00285250 | new_slab
50,144 | 12,536 | 0 | MOVABLE | 0102005a | __page_cache_alloc
52 | 13 | 0 | UNMOVABL | 002084d0 | pte_alloc_one
40 | 10 | 0 | MOVABLE | 000280da | handle_mm_fault
28 | 7 | 0 | UNMOVABL | 000000d0 | __pollwait
20 | 5 | 0 | MOVABLE | 000200da | do_wp_page
20 | 5 | 0 | MOVABLE | 000200da | do_cow_fault
16 | 4 | 0 | UNMOVABL | 00000200 | __tlb_remove_page
16 | 4 | 0 | UNMOVABL | 000084d0 | __pmd_alloc
8 | 2 | 0 | UNMOVABL | 000084d0 | __pud_alloc
... | ... | ... | ... | ... | ...
-----------------------------------------------------------------------------Signed-off-by: Namhyung Kim
Acked-by: Pekka Enberg
Tested-by: Arnaldo Carvalho de Melo
Cc: David Ahern
Cc: Jiri Olsa
Cc: Joonsoo Kim
Cc: Minchan Kim
Cc: Peter Zijlstra
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1429592107-1807-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
04 May, 2015
1 commit
-
It is 'perf kmem' support caller statistics for page. Unlike slab case,
the tracepoints in page allocator don't provide callsite info. So it
records with callchain and extracts callsite info.Note that the callchain contains several memory allocation functions
which has no meaning for users. So skip those functions to get proper
callsites. I used following regex pattern to skip the allocator
functions:^_?_?(alloc|get_free|get_zeroed)_pages?
This gave me a following list of functions:
# perf kmem record --page sleep 3
# perf kmem stat --page -v
...
alloc func: __get_free_pages
alloc func: get_zeroed_page
alloc func: alloc_pages_exact
alloc func: __alloc_pages_direct_compact
alloc func: __alloc_pages_nodemask
alloc func: alloc_page_interleave
alloc func: alloc_pages_current
alloc func: alloc_pages_vma
alloc func: alloc_page_buffers
alloc func: alloc_pages_exact_nid
...The output looks mostly same as --alloc (I also added callsite column
to that) but groups entries by callsite. Currently, the order,
migrate type and GFP flag info is for the last allocation and not
guaranteed to be same for all allocations from the callsite.---------------------------------------------------------------------------------------------
Total_alloc (KB) | Hits | Order | Mig.type | GFP flags | Callsite
---------------------------------------------------------------------------------------------
1,064 | 266 | 0 | UNMOVABL | 000000d0 | __pollwait
52 | 13 | 0 | UNMOVABL | 002084d0 | pte_alloc_one
44 | 11 | 0 | MOVABLE | 000280da | handle_mm_fault
20 | 5 | 0 | MOVABLE | 000200da | do_cow_fault
20 | 5 | 0 | MOVABLE | 000200da | do_wp_page
16 | 4 | 0 | UNMOVABL | 000084d0 | __pmd_alloc
16 | 4 | 0 | UNMOVABL | 00000200 | __tlb_remove_page
12 | 3 | 0 | UNMOVABL | 000084d0 | __pud_alloc
8 | 2 | 0 | UNMOVABL | 00000010 | bio_copy_user_iov
4 | 1 | 0 | UNMOVABL | 000200d2 | pipe_write
4 | 1 | 0 | MOVABLE | 000280da | do_wp_page
4 | 1 | 0 | UNMOVABL | 002084d0 | pgd_alloc
---------------------------------------------------------------------------------------------Signed-off-by: Namhyung Kim
Acked-by: Pekka Enberg
Cc: David Ahern
Cc: Jiri Olsa
Cc: Joonsoo Kim
Cc: Minchan Kim
Cc: Peter Zijlstra
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1429592107-1807-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
29 Apr, 2015
1 commit
-
0d68bc92c48 breaks compiles on RHEL6/OL6:
cc1: warnings being treated as errors
builtin-kmem.c: In function ‘search_page_alloc_stat’:
builtin-kmem.c:322: error: declaration of ‘stat’ shadows a global declaration
node = &parent->rb_left;
/usr/include/sys/stat.h:455: error: shadowed declaration is here
builtin-kmem.c: In function ‘perf_evsel__process_page_alloc_event’:
builtin-kmem.c:378: error: declaration of ‘stat’ shadows a global declaration
/usr/include/sys/stat.h:455: error: shadowed declaration is here
builtin-kmem.c: In function ‘perf_evsel__process_page_free_event’:
builtin-kmem.c:431: error: declaration of ‘stat’ shadows a global declaration
/usr/include/sys/stat.h:455: error: shadowed declaration is hereRename local variable to pstat to avoid the name conflict.
Signed-off-by: David Ahern
Link: http://lkml.kernel.org/r/1429033773-31383-1-git-send-email-david.ahern@oracle.com
Signed-off-by: Arnaldo Carvalho de Melo
24 Apr, 2015
1 commit
-
0d68bc92c48 breaks compiles on RHEL6/OL6:
cc1: warnings being treated as errors
builtin-kmem.c: In function ‘search_page_alloc_stat’:
builtin-kmem.c:322: error: declaration of ‘stat’ shadows a global declaration
node = &parent->rb_left;
/usr/include/sys/stat.h:455: error: shadowed declaration is here
builtin-kmem.c: In function ‘perf_evsel__process_page_alloc_event’:
builtin-kmem.c:378: error: declaration of ‘stat’ shadows a global declaration
/usr/include/sys/stat.h:455: error: shadowed declaration is here
builtin-kmem.c: In function ‘perf_evsel__process_page_free_event’:
builtin-kmem.c:431: error: declaration of ‘stat’ shadows a global declaration
/usr/include/sys/stat.h:455: error: shadowed declaration is hereRename local variable to pstat to avoid the name conflict.
Signed-off-by: David Ahern
Link: http://lkml.kernel.org/r/1429033773-31383-1-git-send-email-david.ahern@oracle.com
Signed-off-by: Arnaldo Carvalho de Melo