diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2014-12-16 18:19:00 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2014-12-17 17:58:14 +0300 |
| commit | 1be300f4cc1ddf975f158b4ab2f880854b29306b (patch) | |
| tree | 14fcb9e184acb2b89c98f5113b45e20f6da5f4c9 | |
| parent | fa37c025c5bec6704dad714365a7f62d9cb13a36 (diff) | |
| download | linux-1be300f4cc1ddf975f158b4ab2f880854b29306b.tar.xz | |
perf tools: Make the mmap length autotuning more robust
If /proc/sys/kernel/perf_event_mlock_kb is not (power of 2 + PAGE_SIZE_in_kb)
and we let the perf tools do mmap length autosizing based on that, then, for
non-CAP_IPC_LOCK users when /proc/sys/kernel/perf_event_paranoid is > -1, then
we get an -EINVAL that ends up in:
[acme@ssdandy linux]$ trace usleep 1
Invalid argument
[acme@ssdandy linux]$ perf record usleep 1
failed to mmap with 22 (Invalid argument)
After this fix:
[acme@ssdandy linux]$ trace usleep 1
<SNIP>
0.806 ( 0.006 ms): munmap(addr: 0x7f7e4740a000, len: 66467) = 0
0.869 ( 0.002 ms): brk( ) = 0x7bb000
0.873 ( 0.003 ms): brk(brk: 0x7dc000 ) = 0x7dc000
0.877 ( 0.001 ms): brk( ) = 0x7dc000
0.953 ( 0.058 ms): nanosleep(rqtp: 0x7fff26ab9420 ) = 0
0.959 ( 0.000 ms): exit_group(
[acme@ssdandy linux]$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.017 MB perf.data (~759 samples) ]
[acme@ssdandy linux]$
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-6p6l5ou6jev6o7ymc4nn1n2a@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/evlist.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 8eb92cf5d552..7d88327d94a9 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -909,6 +909,8 @@ static size_t perf_evlist__mmap_size(unsigned long pages) } pages = (max * 1024) / page_size; + if (!is_power_of_2(pages)) + pages = rounddown_pow_of_two(pages); } else if (!is_power_of_2(pages)) return 0; |