From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: mathieu.poirier@linaro.org, acme@kernel.org
Cc: peterz@infradead.org, coresight@lists.linaro.org,
linux-kernel@vger.kernel.org, alexander.shishkin@linux.intel.com,
mingo@redhat.com, leo.yan@linaro.org, namhyung@kernel.org,
jolsa@redhat.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 02/17] perf tools: Configure timestsamp generation in CPU-wide mode
Date: Fri, 7 Jun 2019 10:41:48 +0100 [thread overview]
Message-ID: <c1507e8b-9ec8-a5c4-a398-20dcc47acaa8@arm.com> (raw)
In-Reply-To: <20190524173508.29044-3-mathieu.poirier@linaro.org>
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 */
Cheers
Suzuki
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next prev parent reply other threads:[~2019-06-07 9:41 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-24 17:34 [PATCH v2 00/17] perf tools: Coresight: Add CPU-wide trace support Mathieu Poirier
2019-05-24 17:34 ` [PATCH v2 01/17] perf tools: Configure contextID tracing in CPU-wide mode Mathieu Poirier
2019-06-07 9:21 ` Suzuki K Poulose
2019-06-07 17:40 ` Mathieu Poirier
2019-06-07 18:20 ` Arnaldo Carvalho de Melo
2019-06-07 19:33 ` Mathieu Poirier
2019-05-24 17:34 ` [PATCH v2 02/17] perf tools: Configure timestsamp generation " Mathieu Poirier
2019-06-07 9:41 ` Suzuki K Poulose [this message]
2019-06-07 17:46 ` Mathieu Poirier
2019-06-07 18:34 ` Arnaldo Carvalho de Melo
2019-05-24 17:34 ` [PATCH v2 03/17] perf tools: Configure SWITCH_EVENTS " Mathieu Poirier
2019-05-24 17:34 ` [PATCH v2 04/17] perf tools: Add handling of itrace start events Mathieu Poirier
2019-05-24 17:34 ` [PATCH v2 05/17] perf tools: Add handling of switch-CPU-wide events Mathieu Poirier
2019-05-24 17:34 ` [PATCH v2 06/17] perf tools: Refactor error path in cs_etm_decoder__new() Mathieu Poirier
2019-05-24 17:34 ` [PATCH v2 07/17] perf tools: Move packet queue out of decoder structure Mathieu Poirier
2019-05-24 17:34 ` [PATCH v2 08/17] perf tools: Fix indentation in function cs_etm__process_decoder_queue() Mathieu Poirier
2019-05-24 17:35 ` [PATCH v2 09/17] perf tools: Introduce the concept of trace ID queues Mathieu Poirier
2019-05-24 17:35 ` [PATCH v2 10/17] perf tools: Get rid of unused cpu in struct cs_etm_queue Mathieu Poirier
2019-05-24 17:35 ` [PATCH v2 11/17] perf tools: Move thread to traceid_queue Mathieu Poirier
2019-05-24 17:35 ` [PATCH v2 12/17] perf tools: Move tid/pid " Mathieu Poirier
2019-05-24 17:35 ` [PATCH v2 13/17] perf tools: Use traceID aware memory callback API Mathieu Poirier
2019-05-24 17:35 ` [PATCH v2 14/17] perf tools: Add support for multiple traceID queues Mathieu Poirier
2019-05-24 17:35 ` [PATCH v2 15/17] perf tools: Linking PE contextID with perf thread mechanic Mathieu Poirier
2019-05-24 17:35 ` [PATCH v2 16/17] perf tools: Add notion of time to decoding code Mathieu Poirier
2019-06-06 18:50 ` Arnaldo Carvalho de Melo
2019-06-07 14:38 ` Mathieu Poirier
2019-05-24 17:35 ` [PATCH v2 17/17] perf tools: Add support for CPU-wide trace scenarios Mathieu Poirier
2019-05-31 1:45 ` [PATCH v2 00/17] perf tools: Coresight: Add CPU-wide trace support Leo Yan
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