Messages in this thread | | | Date | Sat, 1 Aug 2020 06:40:50 -0500 | From | "Paul A. Clarke" <> | Subject | Re: [PATCHv4 00/19] perf metric: Add support to reuse metric |
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On Wed, Jul 29, 2020 at 11:18:49AM +0200, Jiri Olsa wrote: > this patchset is adding the support to reused metric in > another metric. > > For example, to define IPC by using CPI with change like: > > { > "BriefDescription": "Instructions Per Cycle (per Logical Processor)", > - "MetricExpr": "INST_RETIRED.ANY / CPU_CLK_UNHALTED.THREAD", > + "MetricExpr": "1/CPI", > "MetricGroup": "TopDownL1", > "MetricName": "IPC" > }, > > I won't be able to find all the possible places we could > use this at, so I wonder you guys (who was asking for this) > would try it and come up with comments if there's something > missing or we could already use it at some places. > > It's based on Arnaldo's tmp.perf/core. > > v4 changes: > - removed acks from patch because it changed a bit > with the last fixes: > perf metric: Collect referenced metrics in struct metric_ref_node > - fixed runtime metrics [Kajol Jain] > - increased recursion depth [Paul A. Clarke] > - changed patches due to dependencies: > perf metric: Collect referenced metrics in struct metric_ref_node > perf metric: Add recursion check when processing nested metrics > perf metric: Rename struct egroup to metric > perf metric: Rename group_list to metric_list > > Also available in here: > git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git > perf/metric
I built and ran from the above git branch, and things seem to work. Indeed, I was able to apply my changes to exploit the new capabilities via modifications to tools/perf/pmu-events/arch/powerpc/power9/metrics.json, as I posted earlier (and will submit once this set gets merged).
Tested-by: Paul A. Clarke <pc@us.ibm.com>
One thing I noted, but which also occurs without these patches, is that the perf metrics are not computed unless run as root: -- $ perf stat --metrics br_misprediction_percent command
Performance counter stats for 'command':
1,823,530,051 pm_br_pred:u 2,662,705 pm_br_mpred_cmpl:u
$ /usr/bin/sudo perf stat --metrics br_misprediction_percent command
Performance counter stats for 'command':
1,824,655,269 pm_br_pred # 0.09 br_misprediction_percent 1,654,466 pm_br_mpred_cmpl --
Is that expected? I don't think it's always been that way.
PC
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