Messages in this thread | | | Date | Wed, 13 May 2020 17:31:33 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH v4 3/4] perf stat: Copy counts from prev_raw_counts to evsel->counts |
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On Fri, May 08, 2020 at 03:58:16PM +0800, Jin Yao wrote: > It would be useful to support the overall statistics for perf-stat > interval mode. For example, report the summary at the end of > "perf-stat -I" output. > > But since perf-stat can support many aggregation modes, such as > --per-thread, --per-socket, -M and etc, we need a solution which > doesn't bring much complexity. > > The idea is to use 'evsel->prev_raw_counts' which is updated in > each interval and it's saved with the latest counts. Before reporting > the summary, we copy the counts from evsel->prev_raw_counts to > evsel->counts, and next we just follow non-interval processing. > > In evsel__compute_deltas, this patch saves counts to the member > [cpu0,thread0] of perf_counts for AGGR_GLOBAL. > > That's because after copying evsel->prev_raw_counts to evsel->counts, > perf_counts(evsel->counts, cpu, thread) are all 0 for AGGR_GLOBAL. > Once we go to process_counter_maps again, all members of perf_counts > are 0. > > So this patch uses a trick that saves the previous aggr value to > the member [cpu0,thread0] of perf_counts, then aggr calculation > in process_counter_values can work correctly. > > v4: > --- > Change the commit message. > No functional change. > > Signed-off-by: Jin Yao <yao.jin@linux.intel.com> > --- > tools/perf/util/evsel.c | 1 + > tools/perf/util/stat.c | 24 ++++++++++++++++++++++++ > tools/perf/util/stat.h | 1 + > 3 files changed, 26 insertions(+) > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 28683b0eb738..6fae1ec28886 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -1283,6 +1283,7 @@ void evsel__compute_deltas(struct evsel *evsel, int cpu, int thread, > if (cpu == -1) { > tmp = evsel->prev_raw_counts->aggr; > evsel->prev_raw_counts->aggr = *count; > + *perf_counts(evsel->prev_raw_counts, 0, 0) = *count;
ok, I think I understand that now.. it's only for AGGR_GLOBAL mode, because the perf_stat_process_counter will create aggr values from per cpu values
but why do we need to do that all the time? can't we just set it up before you zero prev_raw_counts in next patch?
if (interval) { stat_config.interval = 0; stat_config.summary = true; perf_evlist__copy_prev_raw_counts(evsel_list);
-> for AGGR_GLOBAL set the counts[0,0] to prev_raw_counts->aggr
perf_evlist__reset_prev_raw_counts(evsel_list); runtime_stat_reset(&stat_config); perf_stat__reset_shadow_per_stat(&rt_stat); }
thanks, jirka
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