Re: [PATCH 04/11] perf test: Fix cpu and thread map leaks in sw_clock_freq test

[Namhyung Kim]

Hi Jiri,

On Tue, Mar 2, 2021 at 2:24 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> On Mon, Mar 01, 2021 at 11:04:02PM +0900, Namhyung Kim wrote:
> > The evlist has the maps with its own refcounts so we don't need to set
> > the pointers to NULL.  Otherwise following error was reported by Asan.
> >
> > Also change the goto label since it doesn't need to have two.
> >
> >   # perf test -v 25
> >   25: Software clock events period values        :
> >   --- start ---
> >   test child forked, pid 149154
> >   mmap size 528384B
> >   mmap size 528384B
> >
> >   =================================================================
> >   ==149154==ERROR: LeakSanitizer: detected memory leaks
> >
> >   Direct leak of 32 byte(s) in 1 object(s) allocated from:
> >     #0 0x7fef5cd071f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
> >     #1 0x56260d5e8b8e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23
> >     #2 0x56260d3df7a9 in thread_map__new_by_tid util/thread_map.c:63
> >     #3 0x56260d2ac6b2 in __test__sw_clock_freq tests/sw-clock.c:65
> >     #4 0x56260d26d8fb in run_test tests/builtin-test.c:428
> >     #5 0x56260d26d8fb in test_and_print tests/builtin-test.c:458
> >     #6 0x56260d26fa53 in __cmd_test tests/builtin-test.c:679
> >     #7 0x56260d26fa53 in cmd_test tests/builtin-test.c:825
> >     #8 0x56260d2dbb64 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
> >     #9 0x56260d165a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
> >     #10 0x56260d165a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
> >     #11 0x56260d165a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
> >     #12 0x7fef5c83cd09 in __libc_start_main ../csu/libc-start.c:308
> >
> >     ...
> >   test child finished with 1
> >   ---- end ----
> >   Software clock events period values      : FAILED!
> >
> > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> > ---
> >  tools/perf/tests/sw-clock.c | 12 ++++--------
> >  1 file changed, 4 insertions(+), 8 deletions(-)
> >
> > diff --git a/tools/perf/tests/sw-clock.c b/tools/perf/tests/sw-clock.c
> > index a49c9e23053b..74988846be1d 100644
> > --- a/tools/perf/tests/sw-clock.c
> > +++ b/tools/perf/tests/sw-clock.c
> > @@ -42,8 +42,8 @@ static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
> >               .disabled = 1,
> >               .freq = 1,
> >       };
> > -     struct perf_cpu_map *cpus;
> > -     struct perf_thread_map *threads;
> > +     struct perf_cpu_map *cpus = NULL;
> > +     struct perf_thread_map *threads = NULL;
> >       struct mmap *md;
> >
> >       attr.sample_freq = 500;
> > @@ -66,14 +66,11 @@ static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
> >       if (!cpus || !threads) {
> >               err = -ENOMEM;
> >               pr_debug("Not enough memory to create thread/cpu maps\n");
> > -             goto out_free_maps;
> > +             goto out_delete_evlist;
> >       }
> >
> >       perf_evlist__set_maps(&evlist->core, cpus, threads);
> >
> > -     cpus    = NULL;
> > -     threads = NULL;
>
> hum, so IIUC we added these and the other you remove in your patches long time ago,
> because there was no refcounting at that time, right?

It seems my original patch just set the maps directly.

  bc96b361cbf9 perf tests: Add a test case for checking sw clock event frequency

And after that Adrian changed it to use the set_maps() helper.

  c5e6bd2ed3e8 perf tests: Fix software clock events test setting maps

It seems we already had the refcounting at the moment.  And then the libperf
renaming happened later.

Thanks,
Namhyung