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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-05-25 16:27:38 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-06-04 15:28:52 +0200 |
| commit | 9132d3d92d8953ee79690408a9a24d938be22cd8 (patch) | |
| tree | 385f92a51cfd839aeaeb04e3c2ce15b4b6de017e /tools | |
| parent | perf tools: Ditch the symbol_conf.nr_events global (diff) | |
| download | linux-9132d3d92d8953ee79690408a9a24d938be22cd8.tar.xz linux-9132d3d92d8953ee79690408a9a24d938be22cd8.zip | |
perf annotate: Add comment about annotated_src->nr_histograms
When we have multiple groups in an evlist, say:
$ perf stat -e '{cycles,instructions},{cache-references,cache-misses}' sleep 1
Performance counter stats for 'sleep 1':
343,134 cycles:u
249,292 instructions:u # 0.73 insn per cycle
15,556 cache-references:u
8,925 cache-misses:u # 57.373 % of all cache refs
1.000957550 seconds time elapsed
$
Then the perf_evsel instances for the two group leaders ("cycles" and
"cache-references") will have evsel->nr_members set to 2, while all the
evsel->evlist->nr_entries will be set to 4, so we can't use
evsel->evlist->nr_entries everywhere, as event groups need to be taken
into account.
But this probably requires us to audit at least the forced-group code,
where we want all of the events to be in a "group", to see them all in
the screen, one column for each, even knowing that they were not
necessarily scheduled to count at the same time by the kernel perf
subsystem.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-2g0vwqnc49wl4ttjk8dvpgcc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/annotate.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h index 7ad503fbff74..3dc4ca1d6c08 100644 --- a/tools/perf/util/annotate.h +++ b/tools/perf/util/annotate.h @@ -202,6 +202,10 @@ struct cyc_hist { /** struct annotated_source - symbols with hits have this attached as in sannotation * * @histograms: Array of addr hit histograms per event being monitored + * nr_histograms: This may not be the same as evsel->evlist->nr_entries if + * we have more than a group in a evlist, where we will want + * to see each group separately, that is why symbol__annotate2() + * sets src->nr_histograms to evsel->nr_members. * @lines: If 'print_lines' is specified, per source code line percentages * @source: source parsed from a disassembler like objdump -dS * @cyc_hist: Average cycles per basic block |