Re: [PATCH v5 7/7] perf test: Add a test for default perf stat command

[Namhyung Kim <namhyung@kernel.org>]

On Fri, Aug 30, 2024 at 09:45:11AM +0100, James Clark wrote:
> 
> 
> On 30/08/2024 9:29 am, James Clark wrote:
> > 
> > 
> > On 30/08/2024 7:32 am, Namhyung Kim wrote:
> > > Hello,
> > > 
> > > On Wed, Aug 28, 2024 at 03:07:21PM +0100, James Clark wrote:
> > > > Test that one cycles event is opened for each core PMU when "perf stat"
> > > > is run without arguments.
> > > > 
> > > > The event line can either be output as "pmu/cycles/" or just "cycles" if
> > > > there is only one PMU. Include 2 spaces for padding in the one PMU case
> > > > to avoid matching when the word cycles is included in metric
> > > > descriptions.
> > > > 
> > > > Signed-off-by: James Clark <james.clark@linaro.org>
> > > > ---
> > > >   tools/perf/tests/shell/stat.sh | 21 +++++++++++++++++++++
> > > >   1 file changed, 21 insertions(+)
> > > > 
> > > > diff --git a/tools/perf/tests/shell/stat.sh
> > > > b/tools/perf/tests/shell/stat.sh
> > > > index 525d0c44fdc6..24ace1de71cc 100755
> > > > --- a/tools/perf/tests/shell/stat.sh
> > > > +++ b/tools/perf/tests/shell/stat.sh
> > > > @@ -148,6 +148,26 @@ test_cputype() {
> > > >     echo "cputype test [Success]"
> > > >   }
> > > > +test_hybrid() {
> > > > +  # Test the default stat command on hybrid devices opens one
> > > > cycles event for
> > > > +  # each CPU type.
> > > > +  echo "hybrid test"
> > > > +
> > > > +  # Count the number of core PMUs
> > > > +  pmus=$(ls /sys/bus/event_source/devices/*/cpus 2>/dev/null | wc -l)
> > > 
> > > Is it working on non-hybrid systems?  I don't think they have cpus file
> > > in the core PMU.
> > > 
> > > Thanks,
> > > Namhyung
> > > 
> > 
> > Good point I only tested on Arm non-hybrid. I can change it to assume 1
> > PMU for no cpus files?
> 
> Or maybe assume 1 if a /sys/bus/event_source/devices/cpu folder exists? Not
> sure which is best but either will work.

Some arch might not have a cpu PMU, I think we can assume 1 and update
only if it finds cpus files.

Thanks,
Namhyung