Messages in this thread | | | From | "Liang, Kan" <> | Subject | RE: [PATCH V8 8/8] perf tools: handle PERF_RECORD_LOST_SAMPLES | Date | Thu, 7 May 2015 14:17:13 +0000 |
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> > On Wed, May 06, 2015 at 03:33:54PM -0400, Kan Liang wrote: > > From: Kan Liang <kan.liang@intel.com> > > > > This patch modified the perf tool to handle the new RECORD type, > > PERF_RECORD_LOST_SAMPLES. > > The number of lost-sample events is stored in > > .nr_events[PERF_EVENT_LOST_SAMPLES]. While the exact number of > samples > > which the kernel dropped is stored in total_lost_samples. > > When the percentage of dropped samples is greater than 5%, a warning > > will be sent out. > > That's nice. Would be good to also print this in perf report --stdio output > (without -D), like the samples are. >
OK, I will do it.
> Could you please do the same for the normal PERF_RECORD_LOST too? > There we don't have a exact percentage, but at least could count the lost > events too. This can be a separate patch of course, doesn't need to be tied > to this patchkit.
I think current perf tool already did that. It will print warning for any lost. Is this what you want?
if (session->tool->lost == perf_event__process_lost && stats->nr_events[PERF_RECORD_LOST] != 0) { ui__warning("Processed %d events and lost %d chunks!\n\n" "Check IO/CPU overload!\n\n", stats->nr_events[0], stats->nr_events[PERF_RECORD_LOST]); }
Thanks, Kan > > > -Andi
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