Em Fri, Jun 07, 2019 at 11:46:32AM -0600, Mathieu Poirier escreveu:
On Fri, 7 Jun 2019 at 03:41, Suzuki K Poulose suzuki.poulose@arm.com wrote:
On 24/05/2019 18:34, Mathieu Poirier wrote:
When operating in CPU-wide mode tracers need to generate timestamps in order to correlate the code being traced on one CPU with what is executed on other CPUs.
Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org
tools/perf/arch/arm/util/cs-etm.c | 57 +++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+)
diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c index 3912f0bf04ed..be1e4f20affa 100644 --- a/tools/perf/arch/arm/util/cs-etm.c +++ b/tools/perf/arch/arm/util/cs-etm.c @@ -99,6 +99,54 @@ static int cs_etm_set_context_id(struct auxtrace_record *itr, return err; }
+static int cs_etm_set_timestamp(struct auxtrace_record *itr,
struct perf_evsel *evsel, int cpu)+{
struct cs_etm_recording *ptr;struct perf_pmu *cs_etm_pmu;char path[PATH_MAX];int err = -EINVAL;u32 val;ptr = container_of(itr, struct cs_etm_recording, itr);cs_etm_pmu = ptr->cs_etm_pmu;if (!cs_etm_is_etmv4(itr, cpu))goto out;/* Get a handle on TRCIRD0 */snprintf(path, PATH_MAX, "cpu%d/%s",cpu, metadata_etmv4_ro[CS_ETMV4_TRCIDR0]);err = perf_pmu__scan_file(cs_etm_pmu, path, "%x", &val);/* There was a problem reading the file, bailing out */if (err != 1) {pr_err("%s: can't read file %s\n",CORESIGHT_ETM_PMU_NAME, path);goto out;}/** TRCIDR0.TSSIZE, bit [28-24], indicates whether global timestamping* is supported:* 0b00000 Global timestamping is not implemented* 0b00110 Implementation supports a maximum timestamp of 48bits.* 0b01000 Implementation supports a maximum timestamp of 64bits.*/val &= GENMASK(28, 24);if (!val) {err = -EINVAL;goto out;}/* All good, let the kernel know */evsel->attr.config |= (1 << ETM_OPT_TS);err = 0;+out:
return err;+}
- static int cs_etm_set_option(struct auxtrace_record *itr, struct perf_evsel *evsel, u32 option) {
@@ -118,6 +166,11 @@ static int cs_etm_set_option(struct auxtrace_record *itr, if (err) goto out; break;
case ETM_OPT_TS:err = cs_etm_set_timestamp(itr, evsel, i);if (err)goto out;break; default: goto out; }@@ -343,6 +396,10 @@ static int cs_etm_recording_options(struct auxtrace_record *itr, err = cs_etm_set_option(itr, cs_etm_evsel, ETM_OPT_CTXTID); if (err) goto out;
err = cs_etm_set_option(itr, cs_etm_evsel, ETM_OPT_TS);if (err)goto out;nit: Could we not do this in one shot, say :
cs_etm_set_option(itr, cs_etm_evsel, ETM_OPT_TS | ETM_OPT_CTXTID) ?rather than iterating over the per-CPU events twice ? The cs_etm_set_option() could simply replace the switch() to :
if (option & ETM_OPT_1) do_something_for_1() if (option & ETM_OPT_2) do_something_for_2(); if (option & ~(ETM_OPT_1 | ETM_OPT_2 |...)) /* do unsupported option */Yes, that is a good optimization.
Arnaldo, do you prefer a new set or another patch on top of this one?
On top of it, as this isn't a fix just an optimization, so no need to go back and fix history to avoid bisection, etc.
Put it in your next set, no need to hurry.
- Arnaldo
Thanks, Mathieu
Cheers Suzuki