Messages in this thread | | | From | Namhyung Kim <> | Date | Wed, 10 Nov 2021 23:28:48 -0800 | Subject | Re: [PATCH v2 4/4] perf arm-spe: Support hardware-based PID tracing |
| |
On Tue, Nov 9, 2021 at 3:50 AM German Gomez <german.gomez@arm.com> wrote: > > If Arm SPE traces contain CONTEXT packets with TID info, use these > values for tracking tid of samples. Otherwise fall back to using context > switch events and display a message warning the user of possible timing > inaccuracies [1]. > > [1] https://lore.kernel.org/lkml/f877cfa6-9b25-6445-3806-ca44a4042eaf@arm.com/ > > Signed-off-by: German Gomez <german.gomez@arm.com> > --- > tools/perf/util/arm-spe.c | 99 +++++++++++++++++++++++++++------------ > 1 file changed, 70 insertions(+), 29 deletions(-) > > diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c > index 230bc7ab2..30b8bb48a 100644 > --- a/tools/perf/util/arm-spe.c > +++ b/tools/perf/util/arm-spe.c > @@ -71,6 +71,7 @@ struct arm_spe { > u64 kernel_start; > > unsigned long num_events; > + u8 use_ctx_pkt_for_pid; > }; > > struct arm_spe_queue { > @@ -226,6 +227,44 @@ 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) > +{ > + struct arm_spe *spe = speq->spe; > + int err = machine__set_current_tid(spe->machine, speq->cpu, tid, tid);
I think we should pass -1 as pid as we don't know the real pid.
Thanks, Namhyung
> + > + if (err) > + return err; > + > + arm_spe_set_pid_tid_cpu(spe, &spe->queues.queue_array[speq->queue_nr]); > + > + return 0; > +} > +
| |