perf evsel: Fix missing inherit + sample read check

[PATCH] perf evsel: Fix missing inherit + sample read check

Posted by Namhyung Kim 1 month, 2 weeks ago

It should not clear the inherit bit simply because the kernel doesn't
support the sample read with it.  IOW the inherit bit should be kept
when the sample read is not requested for the event.

Fixes: 90035d3cd876cb71 ("tools/perf: Allow inherit + PERF_SAMPLE_READ when opening events")
Cc: Ben Gainey <ben.gainey@arm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/evsel.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index d8fd493af01458b7..507f526ccbbcfc36 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2112,7 +2112,8 @@ static int __evsel__prepare_open(struct evsel *evsel, struct perf_cpu_map *cpus,
 
 static void evsel__disable_missing_features(struct evsel *evsel)
 {
-	if (perf_missing_features.inherit_sample_read)
+	if (perf_missing_features.inherit_sample_read && evsel->core.attr.inherit &&
+	    (evsel->core.attr.sample_type & PERF_SAMPLE_READ))
 		evsel->core.attr.inherit = 0;
 	if (perf_missing_features.branch_counters)
 		evsel->core.attr.branch_sample_type &= ~PERF_SAMPLE_BRANCH_COUNTERS;
-- 
2.47.0.rc0.187.ge670bccf7e-goog

Re: [PATCH] perf evsel: Fix missing inherit + sample read check

Posted by Namhyung Kim 1 month, 1 week ago

On Tue, 08 Oct 2024 23:22:50 -0700, Namhyung Kim wrote:

> It should not clear the inherit bit simply because the kernel doesn't
> support the sample read with it.  IOW the inherit bit should be kept
> when the sample read is not requested for the event.
> 
> 

Applied to perf-tools-next, thanks!

Best regards,
Namhyung

Re: [PATCH] perf evsel: Fix missing inherit + sample read check

Posted by Ben Gainey 1 month, 2 weeks ago

On Tue, 2024-10-08 at 23:22 -0700, Namhyung Kim wrote:
> It should not clear the inherit bit simply because the kernel doesn't
> support the sample read with it.  IOW the inherit bit should be kept
> when the sample read is not requested for the event.


Ah, sorry. Good spot.

Thanks
Ben



> 
> Fixes: 90035d3cd876cb71 ("tools/perf: Allow inherit +
> PERF_SAMPLE_READ when opening events")
> Cc: Ben Gainey <ben.gainey@arm.com>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/util/evsel.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index d8fd493af01458b7..507f526ccbbcfc36 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -2112,7 +2112,8 @@ static int __evsel__prepare_open(struct evsel
> *evsel, struct perf_cpu_map *cpus,
>  
>  static void evsel__disable_missing_features(struct evsel *evsel)
>  {
> - if (perf_missing_features.inherit_sample_read)
> + if (perf_missing_features.inherit_sample_read && evsel-
> >core.attr.inherit &&
> +     (evsel->core.attr.sample_type & PERF_SAMPLE_READ))
>   evsel->core.attr.inherit = 0;
>   if (perf_missing_features.branch_counters)
>   evsel->core.attr.branch_sample_type &=
> ~PERF_SAMPLE_BRANCH_COUNTERS;

Re: [PATCH] perf evsel: Fix missing inherit + sample read check

Posted by Namhyung Kim 1 month, 2 weeks ago

On Fri, Oct 11, 2024 at 08:02:04AM +0000, Ben Gainey wrote:
> On Tue, 2024-10-08 at 23:22 -0700, Namhyung Kim wrote:
> > It should not clear the inherit bit simply because the kernel doesn't
> > support the sample read with it.  IOW the inherit bit should be kept
> > when the sample read is not requested for the event.
> 
> 
> Ah, sorry. Good spot.

Thanks for the review, can I translate it your Acked-by?

Thanks,
Namhyung
 
> > 
> > Fixes: 90035d3cd876cb71 ("tools/perf: Allow inherit +
> > PERF_SAMPLE_READ when opening events")
> > Cc: Ben Gainey <ben.gainey@arm.com>
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
> >  tools/perf/util/evsel.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > index d8fd493af01458b7..507f526ccbbcfc36 100644
> > --- a/tools/perf/util/evsel.c
> > +++ b/tools/perf/util/evsel.c
> > @@ -2112,7 +2112,8 @@ static int __evsel__prepare_open(struct evsel
> > *evsel, struct perf_cpu_map *cpus,
> >  
> >  static void evsel__disable_missing_features(struct evsel *evsel)
> >  {
> > - if (perf_missing_features.inherit_sample_read)
> > + if (perf_missing_features.inherit_sample_read && evsel-
> > >core.attr.inherit &&
> > +     (evsel->core.attr.sample_type & PERF_SAMPLE_READ))
> >   evsel->core.attr.inherit = 0;
> >   if (perf_missing_features.branch_counters)
> >   evsel->core.attr.branch_sample_type &=
> > ~PERF_SAMPLE_BRANCH_COUNTERS;
>

Re: [PATCH] perf evsel: Fix missing inherit + sample read check

Posted by Ben Gainey 1 month, 2 weeks ago

On Fri, 2024-10-11 at 09:39 -0700, Namhyung Kim wrote:
> On Fri, Oct 11, 2024 at 08:02:04AM +0000, Ben Gainey wrote:
> > On Tue, 2024-10-08 at 23:22 -0700, Namhyung Kim wrote:
> > > It should not clear the inherit bit simply because the kernel
> > > doesn't
> > > support the sample read with it.  IOW the inherit bit should be
> > > kept
> > > when the sample read is not requested for the event.
> > 
> > 
> > Ah, sorry. Good spot.
> 
> Thanks for the review, can I translate it your Acked-by?
> 

Yes, of course

Acked-by: Ben Gainey <ben.gainey@arm.com>

:-)


> Thanks,
> Namhyung
>  
> > > 
> > > Fixes: 90035d3cd876cb71 ("tools/perf: Allow inherit +
> > > PERF_SAMPLE_READ when opening events")
> > > Cc: Ben Gainey <ben.gainey@arm.com>
> > > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > > ---
> > >  tools/perf/util/evsel.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > > index d8fd493af01458b7..507f526ccbbcfc36 100644
> > > --- a/tools/perf/util/evsel.c
> > > +++ b/tools/perf/util/evsel.c
> > > @@ -2112,7 +2112,8 @@ static int __evsel__prepare_open(struct
> > > evsel
> > > *evsel, struct perf_cpu_map *cpus,
> > >  
> > >  static void evsel__disable_missing_features(struct evsel *evsel)
> > >  {
> > > - if (perf_missing_features.inherit_sample_read)
> > > + if (perf_missing_features.inherit_sample_read && evsel-
> > > > core.attr.inherit &&
> > > +     (evsel->core.attr.sample_type & PERF_SAMPLE_READ))
> > >   evsel->core.attr.inherit = 0;
> > >   if (perf_missing_features.branch_counters)
> > >   evsel->core.attr.branch_sample_type &=
> > > ~PERF_SAMPLE_BRANCH_COUNTERS;
> >