Re: [PATCH] perf vendor events: Update PMC used in PM_RUN_INST_CMPL event for power10 platform

[Athira Rajeev <atrajeev@linux.vnet.ibm.com>]

> On 16-Oct-2023, at 8:01 PM, Kajol Jain <kjain@linux.ibm.com> wrote:
> 
> The CPI_STALL_RATIO metric group can be used to present the high
> level CPI stall breakdown metrics in powerpc, which will show:
> 
> - DISPATCH_STALL_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 ( Completion stall cycles per insn )
> 
> Commit cf26e043c2a9 ("perf vendor events power10: Add JSON
> metric events to present CPI stall cycles in powerpc)" which added
> the CPI_STALL_RATIO metric group, also modified
> the PMC value used in PM_RUN_INST_CMPL event from PMC4 to PMC5, 
> to avoid multiplexing of events.
> But that got revert in recent changes. Fix this issue by changing
> back the PMC value used in PM_RUN_INST_CMPL to PMC5.
> 
> Result with the fix:
> 
> ./perf stat --metric-no-group -M CPI_STALL_RATIO <workload>
> 
> Performance counter stats for 'workload':
> 
>        68,745,426      PM_CMPL_STALL                    #     0.21 COMPLETION_STALL_CPI
>         7,692,827      PM_ISSUE_STALL                   #     0.02 ISSUE_STALL_CPI
>       322,638,223      PM_RUN_INST_CMPL                 #     0.05 DISPATCH_STALL_CPI
>                                                  #     0.48 EXECUTION_STALL_CPI
>        16,858,553      PM_DISP_STALL_CYC
>       153,880,133      PM_EXEC_STALL
> 
>       0.089774592 seconds time elapsed
> 
> "--metric-no-group" is used for forcing PM_RUN_INST_CMPL to be scheduled
> in all group for more accuracy.
> 
> Fixes: 7d473f475b2a ("perf vendor events: Move JSON/events to appropriate files for power10 platform")
> Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
> Signed-off-by: Kajol Jain <kjain@linux.ibm.com>

Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>

Thanks
Athira
> ---
> tools/perf/pmu-events/arch/powerpc/power10/pmc.json | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/pmu-events/arch/powerpc/power10/pmc.json b/tools/perf/pmu-events/arch/powerpc/power10/pmc.json
> index c606ae03cd27..0e0253d0e757 100644
> --- a/tools/perf/pmu-events/arch/powerpc/power10/pmc.json
> +++ b/tools/perf/pmu-events/arch/powerpc/power10/pmc.json
> @@ -195,7 +195,7 @@
>     "BriefDescription": "Threshold counter exceeded a value of 128."
>   },
>   {
> -    "EventCode": "0x400FA",
> +    "EventCode": "0x500FA",
>     "EventName": "PM_RUN_INST_CMPL",
>     "BriefDescription": "PowerPC instruction completed while the run latch is set."
>   }
> -- 
> 2.39.3
>