Commit e9add8ba authored Apr 23, 2018 by Jiri Olsa Committed by Arnaldo Carvalho de Melo Apr 23, 2018

perf evsel: Disable write_backward for leader sampling group events



.. and other related fields that do not need to be enabled
for events that have sampling leader.

It fixes the perf top usage Ingo reported broken:

  # perf top -e '{cycles,msr/aperf/}:S'

The 'msr/aperf/' event is configured for write_back sampling, which is
not allowed by the MSR PMU, so it fails to create the event.

Adjusting related attr test.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180423090823.32309-6-jolsa@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 9a4a931c

tools/perf/tests/attr/test-record-group-sampling

+3 −0

Original line number	Diff line number	Diff line
		@@ -35,3 +35,6 @@ inherit=0
		# sampling disabled
		sample_freq=0
		sample_period=0
		freq=0
		write_backward=0
		sample_id_all=0

tools/perf/util/evsel.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -930,8 +930,11 @@ void perf_evsel__config(struct perf_evsel evsel, struct record_opts opts,
		* than leader in case leader 'leads' the sampling.
		*/
		if ((leader != evsel) && leader->sample_read) {
		attr->freq = 0;
		attr->sample_freq = 0;
		attr->sample_period = 0;
		attr->write_backward = 0;
		attr->sample_id_all = 0;
		}

		if (opts->no_samples)

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