Re: [PATCH v3 1/3] perf evsel: Improve the evsel__open_strerror for EBUSY

[Ian Rogers]

On Tue, Nov 5, 2024 at 4:30 PM Chun-Tse Shao <ctshao@xxxxxxxxxx> wrote:
>
> From: Ian Rogers <irogers@xxxxxxxxxx>
>
> The existing EBUSY strerror message is:
>
>   The sys_perf_event_open() syscall returned with 16 (Device or resource busy) for event (intel_bts//).
>   "dmesg | grep -i perf" may provide additional information.
>
> The dmesg won't be useful. What is more useful is knowing what
> processes are potentially using the PMU, which some procfs scanning can
> reveal. When parallel testing tests/shell/stat_all_pmu.sh this yields:
>
>   Testing intel_bts//
>   Error:
>   The PMU intel_bts counters are busy and in use by another process.
>   Possible processes:
>   2585882 perf list
>   2585902 perf list -j -o /tmp/__perf_test.list_output.json.KF9MY
>   2585904 perf list
>   2585911 perf record -e task-clock --filter period > 1 -o /dev/null --quiet true
>   2585912 perf list
>   2585915 perf list
>   2586042 /tmp/perf/perf record -asdg -e cpu-clock -o /tmp/perftool-testsuite_report.dIF/perf_report/perf.data -- sleep 2
>   2589078 perf record -g -e task-clock:u -o - perf test -w noploop
>   2589148 /tmp/perf/perf record --control=fifo:control,ack -e cpu-clock -m 1 sleep 10
>   2589379 perf --buildid-dir /tmp/perf.debug.Umx record --buildid-all -o /tmp/perf.data.YBm /tmp/perf.ex.MD5.ZQW
>   2589568 perf record -o /tmp/__perf_test.program.mtcZH/perf.data --branch-filter any,save_type,u -- perf test -w brstack
>   2589649 perf record --per-thread -o /tmp/__perf_test.perf.data.5d3dc perf test -w thloop
>   2589898 perf record -o /tmp/perf-test-script.BX2b27Dcnj/pp-perf.data --sample-cpu uname
>
> Which gets a little closer to finding the issue.
>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>

Ping.

Thanks,
Ian