Re: [PATCH] perf test: Fix perf test case 84 on s390

[Ian Rogers]

On Fri, Oct 18, 2024 at 1:17 AM Thomas Richter <tmricht@xxxxxxxxxxxxx> wrote:
>
> Perf test case 84 'perf pipe recording and injection test'
> sometime fails on s390, especially on z/VM virtual machines.
>
> This is caused by a very short run time of workload
>
>   # perf test -w noploop
>
> which runs for 1 second. Occasionally this is not long
> enough and the perf report has no samples for symbol noploop.
>
> Fix this and enlarge the runtime for the perf work load
> to 3 seconds. This ensures the symbol noploop is always
> present. Since only s390 is affected, make this loop
> architecture dependend.
>
> Output before:
>  Inject -b build-ids test
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.195 MB - ]
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.277 MB - ]
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.195 MB - ]
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.160 MB
>                          /tmp/perf.data.ELzRdq (4031 samples) ]
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.195 MB - ]
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.195 MB - ]
>  Inject -b build-ids test [Success]
>
>  Inject --buildid-all build-ids test
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.195 MB - ]
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.014 MB - ]
>  Inject --buildid-all build-ids test [Failed - cannot find
>                                 noploop function in pipe #2]
>
> Output after:
> Successful execution for over 10 times in a loop.
>
> Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
> Reviewed-by: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
> Suggested-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Lgtm, fwiw if we can land the parallel testing [1] I'm not sure it
matters if a test takes 3 seconds to run as long as it is running
amongst the concurrently running tests.

Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian
[1] https://lore.kernel.org/lkml/20241018054719.1004128-1-irogers@xxxxxxxxxx/

> ---
>  tools/perf/tests/shell/pipe_test.sh | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/tools/perf/tests/shell/pipe_test.sh b/tools/perf/tests/shell/pipe_test.sh
> index d4c8005ce9b9..e459aa99a951 100755
> --- a/tools/perf/tests/shell/pipe_test.sh
> +++ b/tools/perf/tests/shell/pipe_test.sh
> @@ -13,6 +13,7 @@ skip_test_missing_symbol ${sym}
>  data=$(mktemp /tmp/perf.data.XXXXXX)
>  data2=$(mktemp /tmp/perf.data2.XXXXXX)
>  prog="perf test -w noploop"
> +[ "$(uname -m)" = "s390x" ] && prog="$prog 3"
>  err=0
>
>  set -e
> --
> 2.47.0
>
>