diff mbox series

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

Message ID 20190524173508.29044-3-mathieu.poirier@linaro.org
State New
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(+)

-- 
2.17.1

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


-- 

- Arnaldo
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 */