On Mon Oct 5, 2026 at 11:37 AM CEST, Jonathan Bastari Thamrin via B4 Relay wrote: > From: Jonathan Bastari Thamrin <[email protected]> > > wq test fails with ok_sleepable reading 0 instead of 2 as workqueue > callback hasn't executed before check. > > This happens as callback runs later on a kworker and 50us isn't always > enough. > > Change from 50us sleep to polling over 1s. > > Before (usleep(50)): 3 fails out of 5000 runs > Diagnosing issue (usleep(0)): 23 out of 100 runs > After (Polling): 0 out of 5000 runs > Tested using vmtest on x86_64, test pinned to one CPU with `yes` load > > Link: https://github.com/kernel-patches/vmtest/issues/455 > > Signed-off-by: Jonathan Bastari Thamrin <[email protected]> > --- > tools/testing/selftests/bpf/prog_tests/wq.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/bpf/prog_tests/wq.c > b/tools/testing/selftests/bpf/prog_tests/wq.c > index 84831eecc..b55d8547f 100644 > --- a/tools/testing/selftests/bpf/prog_tests/wq.c > +++ b/tools/testing/selftests/bpf/prog_tests/wq.c > @@ -7,7 +7,7 @@ > void serial_test_wq(void) > { > struct wq *wq_skel = NULL; > - int err, prog_fd; > + int err, prog_fd, tries; > > LIBBPF_OPTS(bpf_test_run_opts, topts); > > @@ -28,7 +28,13 @@ void serial_test_wq(void) > ASSERT_OK(err, "test_run"); > ASSERT_EQ(topts.retval, 0, "test_run"); > > - usleep(50); /* 10 usecs should be enough, but give it extra */ > + /* loop check over 1 sec to make sure it doesn't fail early when busy */ > + for (tries = 1000; tries >= 0; tries--) { > + if (wq_skel->bss->ok_sleepable == (1 << 1)) > + break; > + > + usleep(1000); > + } >
Please figure out the actual condition this loop is trying to wait for and establish it directly, there are several examples in the selftests. pw-bot: cr
