Re: [PATCH] perf/test: reduce run time of perf test Test java symbol

From: Ian Rogers
Date: Tue May 09 2023 - 13:35:13 EST


On Tue, May 9, 2023 at 6:19 AM Thomas Richter <tmricht@xxxxxxxxxxxxx> wrote:
>
> Test case Test java symbol might run a long time. On Fedora 38 the
> run time is very, very long:
>
> Output before:
> # time ./perf test 108
> 108: Test java symbol : Ok
> real 22m15.775s
> user 3m42.584s
> sys 4m30.685s
> #
>
> The reason is a lookup for the server for debug symbols as shown in
> # cat /etc/debuginfod/elfutils.urls
> https://debuginfod.fedoraproject.org/
> #
> This lookup is done for every symbol/sample, so about 3500 lookups
> will take place.
> To omit this lookup, which is not needed, unset environment variable
> DEBUGINFOD_URLS=''.
>
> Output after:
> # time ./perf test 108
> 108: Test java symbol : Ok
>
> real 0m6.242s
> user 0m4.982s
> sys 0m3.243s
> #
>
> Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
> Cc: leo.yan@xxxxxxxxxx
> Cc: irogers@xxxxxxxxxx
> ---
> tools/perf/tests/shell/test_java_symbol.sh | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/tests/shell/test_java_symbol.sh b/tools/perf/tests/shell/test_java_symbol.sh
> index 90cea8811926..499539d1c479 100755
> --- a/tools/perf/tests/shell/test_java_symbol.sh
> +++ b/tools/perf/tests/shell/test_java_symbol.sh
> @@ -56,7 +56,7 @@ if [ $? -ne 0 ]; then
> exit 1
> fi
>
> -if ! perf inject -i $PERF_DATA -o $PERF_INJ_DATA -j; then
> +if ! DEBUGINFOD_URLS='' perf inject -i $PERF_DATA -o $PERF_INJ_DATA -j; then

Jiri, is this the best way to workaround a debuginfod slowness?

Thanks,
Ian

> echo "Fail to inject samples"
> exit 1
> fi
> --
> 2.40.0
>