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>

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;
 }