Commit-ID: 1be300f4cc1ddf975f158b4ab2f880854b29306b Gitweb: http://git.kernel.org/tip/1be300f4cc1ddf975f158b4ab2f880854b29306b Author: Arnaldo Carvalho de Melo <[email protected]> AuthorDate: Tue, 16 Dec 2014 12:19:00 -0300 Committer: Arnaldo Carvalho de Melo <[email protected]> CommitDate: Wed, 17 Dec 2014 11:58:14 -0300
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 <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: David Ahern <[email protected]> Cc: Don Zickus <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/util/evlist.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 8eb92cf..7d88327 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
