* Mark Brown broonie@kernel.org 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@linaro.org Signed-off-by: Mark Brown broonie@kernel.org
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