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authorNamhyung Kim <namhyung@kernel.org>2021-11-11 13:36:22 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2021-11-13 18:11:50 -0300
commit9dc9855f18ba25d2bc536ea5ba6682855e385d66 (patch)
treea97678b039fd0520da0c03b23be993cafef6327e /tools/perf/arch
parent3ca3af7d1f230d1f93ba4cd8cd9d054870f2406f (diff)
downloadlinux-9dc9855f18ba25d2bc536ea5ba6682855e385d66.tar.gz
perf arm-spe: Track task context switch for cpu-mode events
When perf report synthesize events from ARM SPE data, it refers to
current cpu, pid and tid in the machine.  But there's no place to set
them in the ARM SPE decoder.  I'm seeing all pid/tid is set to -1 and
user symbols are not resolved in the output.

  # perf record -a -e arm_spe_0/ts_enable=1/ sleep 1

  # perf report -q | head
     8.77%     8.77%  :-1      [kernel.kallsyms]  [k] format_decode
     7.02%     7.02%  :-1      [kernel.kallsyms]  [k] seq_printf
     7.02%     7.02%  :-1      [unknown]          [.] 0x0000ffff9f687c34
     5.26%     5.26%  :-1      [kernel.kallsyms]  [k] vsnprintf
     3.51%     3.51%  :-1      [kernel.kallsyms]  [k] string
     3.51%     3.51%  :-1      [unknown]          [.] 0x0000ffff9f66ae20
     3.51%     3.51%  :-1      [unknown]          [.] 0x0000ffff9f670b3c
     3.51%     3.51%  :-1      [unknown]          [.] 0x0000ffff9f67c040
     1.75%     1.75%  :-1      [kernel.kallsyms]  [k] ___cache_free
     1.75%     1.75%  :-1      [kernel.kallsyms]  [k] __count_memcg_events

Like Intel PT, add context switch records to track task info.  As ARM
SPE support was added later than PERF_RECORD_SWITCH_CPU_WIDE, I think
we can safely set the attr.context_switch bit and use it.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: German Gomez <german.gomez@arm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211111133625.193568-2-german.gomez@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/arch')
-rw-r--r--tools/perf/arch/arm64/util/arm-spe.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
index 56785034fc84..d32431ac15cc 100644
--- a/tools/perf/arch/arm64/util/arm-spe.c
+++ b/tools/perf/arch/arm64/util/arm-spe.c
@@ -251,8 +251,12 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
 	tracking_evsel->core.attr.sample_period = 1;
 
 	/* In per-cpu case, always need the time of mmap events etc */
-	if (!perf_cpu_map__empty(cpus))
+	if (!perf_cpu_map__empty(cpus)) {
 		evsel__set_sample_bit(tracking_evsel, TIME);
+		evsel__set_sample_bit(tracking_evsel, CPU);
+		/* also track task context switch */
+		tracking_evsel->core.attr.context_switch = 1;
+	}
 
 	return 0;
 }