On Mon, Jan 11, 2021 at 09:45:12AM +0000, Suzuki Kuruppassery Poulose wrote:
Hi Leo,
On 1/9/21 7:44 AM, Leo Yan wrote:
It's possible for CoreSight to trace PID in either CONTEXTIDR_EL1 or CONTEXTIDR_EL2, the PID format info is used to distinguish the PID is traced in which register.
This patch saves PID format into the metadata when record.
The patch looks good to me. One minor suggestion below
Signed-off-by: Leo Yan leo.yan@linaro.org
tools/perf/arch/arm/util/cs-etm.c | 21 +++++++++++++++++++++ tools/perf/util/cs-etm.c | 2 ++ tools/perf/util/cs-etm.h | 2 ++ 3 files changed, 25 insertions(+)
diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c index fad7b6e13ccc..ee78df3b1b07 100644 --- a/tools/perf/arch/arm/util/cs-etm.c +++ b/tools/perf/arch/arm/util/cs-etm.c @@ -613,6 +613,7 @@ static void cs_etm_get_metadata(int cpu, u32 *offset, struct cs_etm_recording *ptr = container_of(itr, struct cs_etm_recording, itr); struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
- u64 pid_fmt; /* first see what kind of tracer this cpu is affined to */ if (cs_etm_is_etmv4(itr, cpu)) {
@@ -641,6 +642,16 @@ static void cs_etm_get_metadata(int cpu, u32 *offset, metadata_etmv4_ro [CS_ETMV4_TRCAUTHSTATUS]);
/** The PID format will be used when decode the trace data;* based on it the decoder will make decision for setting* sample's PID as context_id or VMID.*/pid_fmt = perf_pmu__format_bits(&cs_etm_pmu->format, "pid");if (!pid_fmt)pid_fmt = 1ULL << ETM_OPT_CTXTID;info->priv[*offset + CS_ETMV4_PID_FMT] = pid_fmt;Given we do this same step twice here in this function and also in patch 2. I am wondering if this could be made into a small helper function ?
static u64 cs_etm_pmu_format_pid(cs_etm_pm) { pid_fmt = perf_pmu__format_bits(&cs_etm_pmu->format, "pid"); /* * An older kernel doesn't expose this, so fall back to using * CTXTID. */ if (!pid_fmt) pid_fmt = 1ULL << ETM_OPT_CTXTID; return pid_fmt; }
Agreed; will follow up this suggestion.
Thanks, Leo