From: Namhyung Kim namhyung@kernel.org
mainline inclusion from mainline-v5.16-rc1 commit 9dc9855f18ba category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4NGPV CVE: NA
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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 Signed-off-by: Wei Li liwei391@huawei.com Reviewed-by: Yang Jihong yangjihong1@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- tools/perf/arch/arm64/util/arm-spe.c | 6 +++++- tools/perf/util/arm-spe.c | 25 +++++++++++++++++++++++++ 2 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c index 23e72d50565f..2bbfd5625b27 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; } diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c index 2196291976d9..9e3a6c54801d 100644 --- a/tools/perf/util/arm-spe.c +++ b/tools/perf/util/arm-spe.c @@ -681,6 +681,25 @@ static int arm_spe_process_timeless_queues(struct arm_spe *spe, pid_t tid, return 0; }
+static int arm_spe_context_switch(struct arm_spe *spe, union perf_event *event, + struct perf_sample *sample) +{ + pid_t pid, tid; + int cpu; + + if (!(event->header.misc & PERF_RECORD_MISC_SWITCH_OUT)) + return 0; + + pid = event->context_switch.next_prev_pid; + tid = event->context_switch.next_prev_tid; + cpu = sample->cpu; + + if (tid == -1) + pr_warning("context_switch event has no tid\n"); + + return machine__set_current_tid(spe->machine, cpu, pid, tid); +} + static int arm_spe_process_event(struct perf_session *session, union perf_event *event, struct perf_sample *sample, @@ -718,6 +737,12 @@ static int arm_spe_process_event(struct perf_session *session, } } else if (timestamp) { err = arm_spe_process_queues(spe, timestamp); + if (err) + return err; + + if (event->header.type == PERF_RECORD_SWITCH_CPU_WIDE || + event->header.type == PERF_RECORD_SWITCH) + err = arm_spe_context_switch(spe, event, sample); }
return err;