Re: [PATCH v2] perf script: Fix output type for dynamically allocated core PMU's

From: Falcon, Thomas
Date: Fri Dec 13 2024 - 15:40:35 EST


On Fri, 2024-12-13 at 15:21 -0500, Liang, Kan wrote:
>
>
> On 2024-12-13 3:11 p.m., Thomas Falcon wrote:
> > perf script output may show different fields on different core
> > PMU's
> > that exist on heterogeneous platforms. For example,
> >
> > perf record -e "{cpu_core/mem-loads-aux/,cpu_core/event=0xcd,\
> > umask=0x01,ldlat=3,name=MEM_UOPS_RETIRED.LOAD_LATENCY/}:upp"\
> > -c10000 -W -d -a -- sleep 1
> >
> > perf script:
> >
> > chromium-browse   46572 [002] 544966.882384:     
> > 10000  cpu_core/MEM_UOPS_RETIRED.LOAD_LATENCY/: 7ffdf1391b0c     10268100142\
> >  |OP LOAD|LVL L1 hit|SNP None|TLB L1 or L2 hit|LCK No|BLK    N/A   
> > 5   7    0   7fad7c47425d [unknown] (/usr/lib64/libglib-
> > 2.0.so.0.8000.3)
> >
> > perf record -e cpu_atom/event=0xd0,umask=0x05,ldlat=3,\
> > name=MEM_UOPS_RETIRED.LOAD_LATENCY/upp -c10000 -W -d -a -- sleep 1
> >
> > perf script:
> >
> > gnome-control-c  534224 [023] 544951.816227:      10000
> > cpu_atom/MEM_UOPS_RETIRED.LOAD_LATENCY/:   7f0aaaa0aae0  [unknown]
> > (/usr/lib64/libglib-2.0.so.0.8000.3)
> >
> > Some fields, such as data_src, are not included by default.
> >
> > The cause is that while one PMU may be assigned a type such as
> > PERF_TYPE_RAW, other core PMU's are dynamically allocated at boot
> > time.
> > If this value does not match an existing PERF_TYPE_X value,
> > output_type(perf_event_attr.type) will return OUTPUT_TYPE_OTHER.
> >
> > Instead search for a core PMU with a matching perf_event_attr type
> > and, if one is found, return PERF_TYPE_RAW to match output of other
> > core PMU's.
> >
> > Suggested-by: Kan Liang <kan.liang@xxxxxxxxx>
> > Signed-off-by: Thomas Falcon <thomas.falcon@xxxxxxxxx>
> > ---
> > v2: restrict pmu lookup to platforms with more than one core pmu
> > ---
> >  tools/perf/builtin-script.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> >
> > diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-
> > script.c
> > index 9e47905f75a6..459794c737ce 100644
> > --- a/tools/perf/builtin-script.c
> > +++ b/tools/perf/builtin-script.c
> > @@ -384,6 +384,18 @@ static int evsel_script__fprintf(struct
> > evsel_script *es, FILE *fp)
> >          st.st_size / 1024.0 / 1024.0, es->filename,
> > es->samples);
> >  }
> >  
> > +static bool output_type_many_core_pmus(unsigned int type)
> > +{
> > + struct perf_pmu *pmu;
> > +
> > + if (perf_pmus__num_core_pmus() > 1) {
> > + pmu = perf_pmus__find_by_type(type);
> > + if (pmu && pmu->is_core)>
> > + return true;
>
> I think it should be good enough to search the core_pmus.
> list_for_each_entry(pmu, &core_pmus, list) {
> if (pmu->type == type)
> return true;
> }
>
> Thanks,
> Kan

Thanks, will resend with your changes.

Tom

> > + }
> > + return false;
> > +}
> > +
> >  static inline int output_type(unsigned int type)
> >  {
> >   switch (type) {
> > @@ -394,6 +406,9 @@ static inline int output_type(unsigned int
> > type)
> >   return type;
> >   }
> >  
> > + if (output_type_many_core_pmus(type))
> > + return PERF_TYPE_RAW;
> > +
> >   return OUTPUT_TYPE_OTHER;
> >  }
> >  
>