On 31/01/2021 14:01, Leo Yan wrote: > Option 1: by merging patches 07/08 and 08/08, we can firstly support PID > tracing for root namespace, and later we can extend to support PID > tracing in container (and in VMs). > > Option 2: we can use the software method to establish PID for SPE > trace, which can base on kernel's events PERF_RECORD_SWITCH / > PERF_RECORD_SWITCH_CPU_WIDE and check context switch ip. > > To be honest, I am a bit concern for option 1 for later might > introduce regression when later support PID for containers (and VMs). > If you have a plan for option 1, I think it's good to record current > limitation and the plan for next step in the commit log, so we can merge > this patch at this time and later extend for containers. > > Otherwise, we need to consider how to implement the PID tracing with > option 2. If it is the case, we should firstly only merge patches > 01 ~ 06 for data source enabling. How about you think for this? In my opinion we should do option 1 and use what is there at the moment. That gets users 90% of the functionality right now. I plan to look at option 2 at some point, and it can always be added on top of option 1 or replace what is there. But I don't know when I would get to it or how long it will take. James > >> Signed-off-by: Leo Yan <leo....@linaro.org> >> Signed-off-by: James Clark <james.cl...@arm.com> > > Besides for techinical question, you could add your "Co-developed-by" > tags for patches 06, 07, 08/08, which you have took time to refin them. > > Thanks you for kindly efforts. > > [1] https://lore.kernel.org/patchwork/patch/1353286/ > >> Cc: Peter Zijlstra <pet...@infradead.org> >> Cc: Ingo Molnar <mi...@redhat.com> >> Cc: Arnaldo Carvalho de Melo <a...@kernel.org> >> Cc: Mark Rutland <mark.rutl...@arm.com> >> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> >> Cc: Jiri Olsa <jo...@redhat.com> >> Cc: Namhyung Kim <namhy...@kernel.org> >> Cc: John Garry <john.ga...@huawei.com> >> Cc: Will Deacon <w...@kernel.org> >> Cc: Mathieu Poirier <mathieu.poir...@linaro.org> >> Cc: Al Grant <al.gr...@arm.com> >> Cc: Andre Przywara <andre.przyw...@arm.com> >> Cc: Wei Li <liwei...@huawei.com> >> Cc: Tan Xiaojun <tanxiao...@huawei.com> >> Cc: Adrian Hunter <adrian.hun...@intel.com> >> --- >> tools/perf/util/arm-spe.c | 75 ++++++++++++++++++++++++++------------- >> 1 file changed, 50 insertions(+), 25 deletions(-) >> >> diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c >> index 27a0b9dfe22d..9828fad7e516 100644 >> --- a/tools/perf/util/arm-spe.c >> +++ b/tools/perf/util/arm-spe.c >> @@ -223,6 +223,46 @@ static inline u8 arm_spe_cpumode(struct arm_spe *spe, >> u64 ip) >> PERF_RECORD_MISC_USER; >> } >> >> +static void arm_spe_set_pid_tid_cpu(struct arm_spe *spe, >> + struct auxtrace_queue *queue) >> +{ >> + struct arm_spe_queue *speq = queue->priv; >> + pid_t tid; >> + >> + tid = machine__get_current_tid(spe->machine, speq->cpu); >> + if (tid != -1) { >> + speq->tid = tid; >> + thread__zput(speq->thread); >> + } else >> + speq->tid = queue->tid; >> + >> + if ((!speq->thread) && (speq->tid != -1)) { >> + speq->thread = machine__find_thread(spe->machine, -1, >> + speq->tid); >> + } >> + >> + if (speq->thread) { >> + speq->pid = speq->thread->pid_; >> + if (queue->cpu == -1) >> + speq->cpu = speq->thread->cpu; >> + } >> +} >> + >> +static int arm_spe_set_tid(struct arm_spe_queue *speq, pid_t tid) >> +{ >> + int err; >> + struct arm_spe *spe = speq->spe; >> + struct auxtrace_queue *queue; >> + >> + err = machine__set_current_tid(spe->machine, speq->cpu, tid, tid); >> + if (err) >> + return err; >> + >> + queue = &speq->spe->queues.queue_array[speq->queue_nr]; >> + arm_spe_set_pid_tid_cpu(speq->spe, queue); >> + return 0; >> +} >> + >> static void arm_spe_prep_sample(struct arm_spe *spe, >> struct arm_spe_queue *speq, >> union perf_event *event, >> @@ -431,6 +471,7 @@ static int arm_spe_sample(struct arm_spe_queue *speq) >> static int arm_spe_run_decoder(struct arm_spe_queue *speq, u64 *timestamp) >> { >> struct arm_spe *spe = speq->spe; >> + const struct arm_spe_record *record; >> int ret; >> >> if (!spe->kernel_start) >> @@ -450,6 +491,11 @@ static int arm_spe_run_decoder(struct arm_spe_queue >> *speq, u64 *timestamp) >> if (ret < 0) >> continue; >> >> + record = &speq->decoder->record; >> + ret = arm_spe_set_tid(speq, record->context_id); >> + if (ret) >> + return ret; >> + >> ret = arm_spe_sample(speq); >> if (ret) >> return ret; >> @@ -500,6 +546,10 @@ static int arm_spe__setup_queue(struct arm_spe *spe, >> >> record = &speq->decoder->record; >> >> + ret = arm_spe_set_tid(speq, record->context_id); >> + if (ret) >> + return ret; >> + >> speq->timestamp = record->timestamp; >> ret = auxtrace_heap__add(&spe->heap, queue_nr, speq->timestamp); >> if (ret) >> @@ -552,31 +602,6 @@ static bool arm_spe__is_timeless_decoding(struct >> arm_spe *spe) >> return timeless_decoding; >> } >> >> -static void arm_spe_set_pid_tid_cpu(struct arm_spe *spe, >> - struct auxtrace_queue *queue) >> -{ >> - struct arm_spe_queue *speq = queue->priv; >> - pid_t tid; >> - >> - tid = machine__get_current_tid(spe->machine, speq->cpu); >> - if (tid != -1) { >> - speq->tid = tid; >> - thread__zput(speq->thread); >> - } else >> - speq->tid = queue->tid; >> - >> - if ((!speq->thread) && (speq->tid != -1)) { >> - speq->thread = machine__find_thread(spe->machine, -1, >> - speq->tid); >> - } >> - >> - if (speq->thread) { >> - speq->pid = speq->thread->pid_; >> - if (queue->cpu == -1) >> - speq->cpu = speq->thread->cpu; >> - } >> -} >> - >> static int arm_spe_process_queues(struct arm_spe *spe, u64 timestamp) >> { >> unsigned int queue_nr; >> -- >> 2.28.0 >>
