* Mark Brown <broonie@xxxxxxxxxx> wrote: > In automated testing it has been found that on many systems the fsgsbase > test fails intermittently. This was reported and discussed a while > back: > > https://lore.kernel.org/lkml/20180126153631.ha7yc33fj5uhitjo@xps/ > > with the analysis concluding that this is a hardware issue affecting a > subset of systems but no fix has been merged as yet. As well as the > actual problem found by testing the intermittent test failure is causing > issues for the people doing the automated testing due to the noise. > > In order to make the testing stable modify the test program to iterate > through the test repeatedly, choosing 5000 iterations based on prior > reports and local testing. This unfortunately greatly increases the > execution time for the selftests when things succeed which isn't great, > in my local tests on a range of systems it pushes the execution time up > to approximately a minute when no failures are encountered. > > Reported-by: Dan Rue <dan.rue@xxxxxxxxxx> > Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> > --- > tools/testing/selftests/x86/fsgsbase.c | 27 +++++++++++++++++++++++++- > 1 file changed, 26 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c > index 6cda6daa1f8c..83410749ff1f 100644 > --- a/tools/testing/selftests/x86/fsgsbase.c > +++ b/tools/testing/selftests/x86/fsgsbase.c > @@ -379,7 +379,7 @@ static void test_unexpected_base(void) > } > } > > -int main() > +int test() > { > pthread_t thread; > > @@ -437,3 +437,28 @@ int main() > > return nerrs == 0 ? 0 : 1; > } > + > +int main() > +{ > + int tries = 5000; > + int i; > + > + if (tries > 1) > + quiet = true; > + > + for (i = 0; i < tries; i++) { > + if (test() != 0) > + break; > + } > + > + if (quiet) { > + if (nerrs) { > + printf("[FAIL] %d errors detected in %d tries\n", > + nerrs, i + 1); > + } else { > + printf("[PASS] %d runs succeeded\n", i); > + } > + } > + > + return nerrs == 0 ? 0 : 1; > +} So this isn't very user-friendly either, previously it would run a testcase and immediately provide output. Now it's just starting and 'hanging': galatea:~/linux/linux/tools/testing/selftests/x86> ./fsgsbase_64 I got bored and Ctrl-C-ed it after ~30 seconds. How long is this supposed to run, and why isn't the user informed? Also, testcases should really be short, so I think a better approach would be to thread the test-case and start an instance on every CPU. That should also excercise SMP bugs, if any. Thanks, Ingo
