Messages in this thread | | | From | Namhyung Kim <> | Date | Wed, 23 Sep 2020 23:15:06 +0900 | Subject | Re: [PATCH 1/2] perf stat: Fix segfault when counting armv8_pmu events |
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On Wed, Sep 23, 2020 at 11:08 PM Jiri Olsa <jolsa@redhat.com> wrote: > > On Wed, Sep 23, 2020 at 10:49:52PM +0900, Namhyung Kim wrote: > > On Wed, Sep 23, 2020 at 2:44 PM Jiri Olsa <jolsa@redhat.com> wrote: > > > > > > On Tue, Sep 22, 2020 at 11:13:45AM +0800, Wei Li wrote: > > > > When executing perf stat with armv8_pmu events with a workload, it will > > > > report a segfault as result. > > > > > > please share the perf stat command line you see that segfault for > > > > It seems the description in the patch 0/2 already has it: > > > > [root@localhost hulk]# tools/perf/perf stat -e > > armv8_pmuv3_0/ll_cache_rd/,armv8_pmuv3_0/ll_cache_miss_rd/ ls > > > /dev/null > > Segmentation fault > > yea I found it, but can't reproduce it.. I see the issue from > patch 2, but not sure what's the problem so far
I think the problem is that armv8_pmu has a cpumask, and the user requested per-task events.
The code tried to open the event with a dummy cpu map since it's not a cpu event, but the pmu has cpu map and it's passed to evsel. So there's confusion somewhere whether it should use evsel->cpus or a dummy map.
Thanks Namhyung
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