[PATCH 5.17 431/772] perf parse-events: Support different format of the topdown event name

Greg Kroah-Hartman
2022-06-07T21:18:59Z

From: Kan Liang <kan.liang@linux.intel.com>

[ Upstream commit e7d1374ed5cb346efd9b3df03814dbc0767adb4e ]

The evsel->name may have a different format for a topdown event, a pure
topdown name (e.g., topdown-fe-bound), or a PMU name + a topdown name
(e.g., cpu/topdown-fe-bound/). The cpu/topdown-fe-bound/ kind format
isn't supported by the arch_evlist__leader(). This format is a very
common format for a hybrid platform, which requires specifying the PMU
name for each event.

Without the patch,

$ perf stat -e '{instructions,slots,cpu/topdown-fe-bound/}' -a sleep 1

Performance counter stats for 'system wide':

<not counted> instructions
<not counted> slots
<not supported> cpu/topdown-fe-bound/

1.003482041 seconds time elapsed

Some events weren't counted. Try disabling the NMI watchdog:
echo 0 > /proc/sys/kernel/nmi_watchdog
perf stat ...
echo 1 > /proc/sys/kernel/nmi_watchdog
The events in group usually have to be from the same PMU. Try reorganizing the group.

With the patch,

$ perf stat -e '{instructions,slots,cpu/topdown-fe-bound/}' -a sleep 1

Performance counter stats for 'system wide':

157,383,996 slots
25,011,711 instructions
27,441,686 cpu/topdown-fe-bound/

1.003530890 seconds time elapsed

Fixes: bc355822f0d9623b ("perf parse-events: Move slots only with topdown")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220518143900.1493980-4-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/arch/x86/util/evlist.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/arch/x86/util/evlist.c b/tools/perf/arch/x86/util/evlist.c
index cfc208d71f00..75564a7df15b 100644
--- a/tools/perf/arch/x86/util/evlist.c
+++ b/tools/perf/arch/x86/util/evlist.c
@@ -36,7 +36,7 @@ struct evsel *arch_evlist__leader(struct list_head *list)
if (slots == first)
return first;
}
- if (!strncasecmp(evsel->name, "topdown", 7))
+ if (strcasestr(evsel->name, "topdown"))
has_topdown = true;
if (slots && has_topdown)
return slots;
--
2.35.1