Messages in this thread | | | Subject | Re: [PATCH v4 3/4] perf stat: Copy counts from prev_raw_counts to evsel->counts | From | "Jin, Yao" <> | Date | Thu, 14 May 2020 13:42:39 +0800 |
| |
Hi Jiri,
On 5/13/2020 11:31 PM, Jiri Olsa wrote: > 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); > } >
Yes, I think that's a good idea.
Now in v5, I create a new patch "perf stat: Save aggr value to first member of prev_raw_counts" to save aggr value to first member of prev_raw_counts for AGGR_GLOBAL. Then next, perf_stat_process_counter can create aggr values from per cpu values successfully.
Thanks Jin Yao
> > thanks, > jirka >
| |