Messages in this thread Patch in this message | | | Date | Fri, 08 Nov 2013 07:41:03 -0700 | From | David Ahern <> | Subject | Re: [PATCH] perf tool: Round mmap pages to power 2 |
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On 11/8/13, 2:11 AM, Adrian Hunter wrote: > This prevents: > > --out-pages=0 > > from working e.g. > > tools/perf/perf record -vv --out-pages=0 uname > rounding mmap pages size to 4096 (1 pages) > > Although without this patch: > > tools/perf/perf record -vv --out-pages=0 uname > --mmap_pages/-m value must be a power of two. > usage: perf record [<options>] [<command>] > or: perf record [<options>] -- <command> [<options>] > > --out-pages <pages> > Number of pages or size with units to use for > output (default 64M) > > Also there is: > > tools/perf/perf record -vv --no-out-pages uname > Segmentation fault (core dumped)
This is problem with perf_evlist__parse_mmap_pages(); same thing happens with --no-map-pages.
With the attached both round a 0 up to 1 page:
[daahern@nxos-vdc-dev3 perf]$ perf record --out-pages 0 uname rounding mmap pages size to 4096 (1 pages) Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.008 MB perf.data (~339 samples) ]
[daahern@nxos-vdc-dev3 perf]$ perf record --mmap-pages 0 uname rounding mmap pages size to 4096 (1 pages) Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.008 MB perf.data (~339 samples) ]
[daahern@nxos-vdc-dev3 perf]$ perf record --no-mmap-pages uname
usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>]
-m, --mmap-pages <pages> number of mmap data pages David
>From fc7c5a6b2b47a2e7a04613b4e82e478a0dcabf42 Mon Sep 17 00:00:00 2001 From: David Ahern <dsahern@gmail.com> Date: Fri, 8 Nov 2013 07:37:43 -0700 Subject: [PATCH] perf record: Fix segfault with --no-mmap-pages
Adrian reported a segfault when using --no-out-pages $ tools/perf/perf record -vv --no-out-pages uname Segmentation fault (core dumped)
The same occurs with --no-mmap-pages. Fix by checking that str is non-NULL before parsing it.
Reported-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: David Ahern <dsahern@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> --- tools/perf/util/evlist.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 9ec3a5a45f22..1f103616d906 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -718,6 +718,9 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str, { .tag = 0 }, }; + if (str == NULL) + return -1; + val = parse_tag_value(str, tags); if (val != (unsigned long) -1) { /* we got file size value */ -- 1.8.3.4 (Apple Git-47)
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