Messages in this thread Patch in this message | | | Date | Mon, 15 Jan 2018 13:04:48 +0800 | From | Wang YanQing <> | Subject | [PATCH] perf:util:dso: Using O_CLOEXEC in do_open |
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I meet strange behavior with below 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: " 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 find out the reason is "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> --- tools/perf/util/dso.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index d5b6f7f..36ef45b 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; -- 1.8.5.6.2.g3d8a54e.dirty
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