2023-05-09 13:29:16

by Thomas Richter

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

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 <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
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
echo "Fail to inject samples"
exit 1
fi
--
2.40.0

2023-05-09 17:50:35

by Ian Rogers

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

On Tue, May 9, 2023 at 6:19 AM Thomas Richter <[email protected]> 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 <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> 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
>

2023-05-09 18:15:02

by Arnaldo Carvalho de Melo

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

Em Tue, May 09, 2023 at 10:34:44AM -0700, Ian Rogers escreveu:
> On Tue, May 9, 2023 at 6:19 AM Thomas Richter <[email protected]> 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 <[email protected]>
> > Cc: [email protected]
> > Cc: [email protected]
> > ---
> > 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?

I noticed this delay, It is good that someone worked on rootcausing this
excessive delay, thanks Thomas.

I'll test it now.

- Arnaldo

2023-05-09 18:26:17

by Arnaldo Carvalho de Melo

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

Em Tue, May 09, 2023 at 03:10:58PM -0300, Arnaldo Carvalho de Melo escreveu:
> > On Tue, May 9, 2023 at 6:19 AM Thomas Richter <[email protected]> wrote:
> > > -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

> I noticed this delay, It is good that someone worked on rootcausing this
> excessive delay, thanks Thomas.
>
> I'll test it now.

gdb asks the user if debuginfod should be used, perf is doing this if
the system is configured for debuginfod queries via a systemwide config,
what is best? Unsure, but since the test passes, i.e. the expected
symbols are found in the 'perf report' output, avoiding debuginfod
queries seems to fit the bill,

Applied,

- Arnaldo