From 9dc9855f18ba25d2bc536ea5ba6682855e385d66 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Thu, 11 Nov 2021 13:36:22 +0000 Subject: [PATCH] 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 Signed-off-by: German Gomez Signed-off-by: Namhyung Kim Cc: Alexander Shishkin Cc: Jiri Olsa Cc: John Garry Cc: Mark Rutland Cc: Mathieu Poirier Cc: Will Deacon 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 --- 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 5678503..d32431a 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 2196291..9e3a6c54 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; -- 2.7.4