Messages in this thread | | | Date | Wed, 17 Dec 2014 14:48:12 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH 15/18] perf tools: Make the mmap length autotuning more robust |
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On Tue, Dec 16, 2014 at 01:57:17PM -0300, Arnaldo Carvalho de Melo wrote: > From: Arnaldo Carvalho de Melo <acme@redhat.com> > > 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> > --- > 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 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);
ok then ;-)
jirka
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