Running "perf list" on powerpc fails with segfault as below:
$ ./perf list
Segmentation fault (core dumped)
$
This happens because of duplicate events in the JSON list. The powerpc
JSON event list contains some event with same event name, but different
event code. They are:
- PM_INST_FROM_L3MISS (Present in datasource and frontend)
- PM_MRK_DATA_FROM_L2MISS (Present in datasource and marked)
- PM_MRK_INST_FROM_L3MISS (Present in datasource and marked)
- PM_MRK_DATA_FROM_L3MISS (Present in datasource and marked)
pmu_events_table__num_events() uses the value from table_pmu->num_entries
which includes duplicate events as well. This causes issue during "perf
list" and results in a segmentation fault.
Since both event codes are valid, append _DSRC to the Data Source events
(datasource.json), so that they would have a unique name.
Also add PM_DATA_FROM_L2MISS_DSRC and PM_DATA_FROM_L3MISS_DSRC events.
With the fix, 'perf list' works as expected.
Fixes: fc14358075 ("perf vendor events power10: Update JSON/events")
Signed-off-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20231123160110.94090-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 cf26e043c2 ("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: 7d473f475b ("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>
Tested-by: Disha Goel<disgoel@linux.ibm.com>
Cc: maddy@linux.ibm.com
Link: https://lore.kernel.org/r/20231016143110.244255-1-kjain@linux.ibm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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@linux.vnet.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Disha Goel <disgoel@linux.ibm.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230216061240.18067-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Testcase stat_all_metrics.sh fails in powerpc:
90: perf all metrics test : FAILED!
The testcase "stat_all_metrics.sh" verifies perf stat result for all the
metric events present in perf list. It runs perf metric events with
various commands and expects non-empty metric result.
Incase of powerpc:hv-24x7 events, some of the event count can be 0 based
on system configuration. And if that event used as denominator in divide
equation, it can cause divide by 0 error. The current nest_metric.json
file creating divide by 0 issue for some of the metric events, which
results in failure of the "stat_all_metrics.sh" test case.
Most of the metrics events have cycles or an event which expect to have
a larger value as denominator, so adding 1 to the denominator of the
metric expression as a fix.
Result in powerpc box after this patch changes:
90: perf all metrics test : Ok
Fixes: a3cbcadfdf ("perf vendor events power10: Adds 24x7 nest metric events for power10 platform")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Link: https://lore.kernel.org/r/20221014140220.122251-1-kjain@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
