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| author | Wang YanQing <udknight@gmail.com> | 2018-01-15 13:04:48 +0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-01-23 09:49:28 -0300 |
| commit | 4c0d8d27954d9efb2a02ec9fc16f39b02f248bb7 (patch) | |
| tree | 644129db3a29b75544c6b4fe99ff8b0f52b2b4ed /tools | |
| parent | 5c61d70e55ab1cb917752f4a0d5f4683b4869e32 (diff) | |
| download | linux-4c0d8d27954d9efb2a02ec9fc16f39b02f248bb7.tar.bz2 | |
perf symbols: Using O_CLOEXEC in do_open
I've meet a strange behavior with these commands on my gentoo box:
1: perf kmem record
2: CTRL-C to stop 1
3: perf report
4: "Enter", "Enter", "Run scripts for all samples",
"event_analyzing_sample".
Then 'perf report' says:
"
No kallsyms or vmlinux with build-id xxxx was found
/lib/modules/4.10.0+/build/vmlinux with build id xxxx not found,
continuing without symbols
".
It is strange because I am sure /lib/modules/4.10.0+/build/vmlinux is
right for perf.data.
After digging, I found out the reason is that "perf report" generates
many open fds, then "script_browse" uses popen to run "perf script"
which run out of open files.
The gentoo box has a small default value for "max open files", 1024.
Yes, "ulimit -n " with a bigger number could fix it, but I think that
using O_CLOEXEC in do_open is a better way.
Signed-off-by: Wang YanQing <udknight@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180115050448.GA20759@udknight
[ Make sure O_CLOEXEC is available in old systems by adding a patch
just before this one, to keep this bisectable in such systems ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/dso.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index d5b6f7f5baff..36ef45b2e89d 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -446,7 +446,7 @@ static int do_open(char *name) char sbuf[STRERR_BUFSIZE]; do { - fd = open(name, O_RDONLY); + fd = open(name, O_RDONLY|O_CLOEXEC); if (fd >= 0) return fd; |