Messages in this thread | | | Date | Wed, 27 Mar 2019 09:58:13 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH 2/4] perf, tools: Implement duration_time as a proper event |
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On Tue, Mar 26, 2019 at 03:18:21PM -0700, Andi Kleen wrote: > From: Andi Kleen <ak@linux.intel.com> > > The perf metric expression use duration_time internally to normalize > events. Normal perf stat without -x also prints the duration time. > But when using -x, the interval is not output anywhere, which > is inconvenient for any post processing which often wants to > normalize values to time. > > So implement duration_time as a proper perf event that > can be specified explicitely with -e. > > The previous implementation of duration_time only worked > for metric processing. This adds the concept of a tool > event that is handled by the tool. On the kernel level > it is still mapped to the dummy software event, but the > values are not read anymore, but instead computed by the tool. > > Add proper plumbing to handle this in the event parser, > and display it in perf stat. We don't want duration_time to be added up, > so it's only printed for the first CPU. > > % perf stat -e duration_time,cycles true > > Performance counter stats for 'true': > > 555,476 ns duration_time > 771,958 cycles > > 0.000555476 seconds time elapsed > > 0.000644000 seconds user > 0.000000000 seconds sys > > Signed-off-by: Andi Kleen <ak@linux.intel.com> > --- > tools/perf/builtin-stat.c | 28 ++++++++++++++++++------- > tools/perf/util/evsel.h | 6 ++++++ > tools/perf/util/parse-events.c | 38 +++++++++++++++++++++++++++++----- > tools/perf/util/parse-events.h | 4 ++++ > tools/perf/util/parse-events.l | 11 +++++++++- > tools/perf/util/parse-events.y | 12 +++++++++++ > 6 files changed, 86 insertions(+), 13 deletions(-) > > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index 49ee3c2033ec..7f9c4b7f5d69 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -244,11 +244,25 @@ perf_evsel__write_stat_event(struct perf_evsel *counter, u32 cpu, u32 thread, > process_synthesized_event, NULL); > } > > +static int read_single_counter(struct perf_evsel *counter, int cpu, > + int thread, struct timespec *rs) > +{ > + if (counter->tool_event == PERF_TOOL_DURATION_TIME) { > + u64 val = rs->tv_nsec + rs->tv_sec*1000000000ULL; > + struct perf_counts_values *count = > + perf_counts(counter->counts, cpu, thread); > + count->ena = count->run = val; > + count->val = val; > + return 0; > + } > + return perf_evsel__read_counter(counter, cpu, thread); > +}
so now that we have time in a separate event, we could get rid of the isolated update_stats(&walltime_nsecs_stats) calls and move them to perf_stat__update_shadow_stats?
jirka
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