On Tue, Dec 16, 2014 at 01:57:07PM -0300, Arnaldo Carvalho de Melo wrote: > From: Arnaldo Carvalho de Melo <[email protected]> > > So far what is in there by default is what we were using: 512KB + the > control page, but the admin may change that, and if it does to a smaller > value, all calls to tooling for non root users start failing, requiring > that the user manually set --mmap_pages/-m. > > Use instead what is in /proc/sys/kernel/perf_event_mlock_kb. > > 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 | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > index 7847f3885081..ac808680e61c 100644 > --- a/tools/perf/util/evlist.c > +++ b/tools/perf/util/evlist.c > @@ -893,10 +893,22 @@ out_unmap: > > static size_t perf_evlist__mmap_size(unsigned long pages) > { > - /* 512 kiB: default amount of unprivileged mlocked memory */ > - if (pages == UINT_MAX) > - pages = (512 * 1024) / page_size; > - else if (!is_power_of_2(pages)) > + if (pages == UINT_MAX) { > + int max; > + > + if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) { > + /* > + * Pick a once upon a time good value, i.e. things look > + * strange since we can't read a sysctl value, but lets > not > + * die yet... > + */ > + max = 512; > + } else { > + max -= (page_size / 1024); > + }
so this way you depend on value in perf_event_mlock_kb being power 2, otherwise: # echo 1000 > /proc/sys/kernel/perf_event_mlock_kb $ perf record ls failed to mmap with 22 (Invalid argument) maybe you could use the logic/code from parse_pages_arg function jirka -- 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/
