On Mon, Feb 11, 2019 at 09:49:16AM +0100, Ingo Molnar wrote:
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?
On Intel systems I've got access to it's tended to only run for less than 10 seconds for me with excursions up to ~30s at most, I'd have projected it to be about a minute if the tests pass. However retesting with Debian's v4.19 kernel it seems to be running a lot more stably so we're now seeing it run to completion reliably when just one copy of the test is running.
AFAICT it's not terribly idiomatic to provide much output, and anything that was per iteration would be *way* too spammy.
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.
Well, a *better* approach would be for the underlying issue that the test is finding to be fixed.
I didn't look at adding more threads as the test case is already threaded, it does seem that running multiple copies simultaneously makes things reproduce more quickly so it's definitely useful though it's still taking multiple iterations.