diff mbox series

[v2,02/17] perf tools: Configure timestsamp generation in CPU-wide mode

Message ID 20190524173508.29044-3-mathieu.poirier@linaro.org (mailing list archive)
State New, archived
Headers show
Series perf tools: Coresight: Add CPU-wide trace support | expand

Commit Message

Mathieu Poirier May 24, 2019, 5:34 p.m. UTC 
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(+)

Comments

Suzuki K Poulose June 7, 2019, 9:41 a.m. UTC | #1 
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
Mathieu Poirier June 7, 2019, 5:46 p.m. UTC | #2 
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?

Thanks,
Mathieu

>
> Cheers
> Suzuki
Arnaldo Carvalho de Melo June 7, 2019, 6:34 p.m. UTC | #3 
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
diff mbox series

Patch

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;
 	}
 
 	/* Add dummy event to keep tracking */