[PATCH] powerpc/perf: Add json metric events to present CPI stall cycles in powerpc

[Arnaldo Carvalho de Melo]

Em Thu, Feb 16, 2023 at 10:10:05AM -0800, Ian Rogers escreveu:
> On Wed, Feb 15, 2023 at 10:12 PM Athira Rajeev
> <atrajeev at linux.vnet.ibm.com> wrote:
> >
> > Power10 Performance Monitoring Unit (PMU) provides events
> > to understand stall cycles of different pipeline stages.
> > These events along with completed instructions provides
> > useful metrics for application tuning.
> >
> > Patch implements the json changes to collect counter statistics
> > to present the high level CPI stall breakdown metrics. New metric
> > group is named as "CPI_STALL_RATIO" and this new metric group
> > presents these stall metrics:
> > - DISPATCHED_CPI ( Dispatch stall cycles per insn )
> > - ISSUE_STALL_CPI ( Issue stall cycles per insn )
> > - EXECUTION_STALL_CPI ( Execution stall cycles per insn )
> > - COMPLETION_STALL_CPI ( Completition stall cycles per insn )
> >
> > To avoid multipling of events, PM_RUN_INST_CMPL event has been
> > modified to use PMC5(performance monitoring counter5) instead
> > of PMC4. This change is needed, since completion stall event
> > is using PMC4.
> >
> > Usage example:
> >
> >  ./perf stat --metric-no-group -M CPI_STALL_RATIO <workload>
> >
> >  Performance counter stats for 'workload':
> >
> >     63,056,817,982      PM_CMPL_STALL                    #     0.28 COMPLETION_STALL_CPI
> >  1,743,988,038,896      PM_ISSUE_STALL                   #     7.73 ISSUE_STALL_CPI
> >    225,597,495,030      PM_RUN_INST_CMPL                 #     6.18 DISPATCHED_CPI
> >                                                   #    37.48 EXECUTION_STALL_CPI
> >  1,393,916,546,654      PM_DISP_STALL_CYC
> >  8,455,376,836,463      PM_EXEC_STALL
> >
> > "--metric-no-group" is used for forcing PM_RUN_INST_CMPL to be scheduled
> > in all group for more accuracy.
> >
> > Signed-off-by: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
> 
> Acked-by: Ian Rogers <irogers at google.com>

Thanks, applied.

- Arnaldo