Re: [PATCH bpf] selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep

[Manu Bretelle <chantra@meta.com>]

> On Jul 12, 2024, at 11:08 AM, Puranjay Mohan <puranjay12@gmail.com> wrote:
> 
> Thanks for testing the fix.
> 
> This bug has been resolved now but the test still hangs sometimes.
> Unfortunately, I am not able to reproduce this hang
> using vmtest.

I have not able to reproduce the original error either. I will try to reproduce on the actual CI host next week (which are native arm64 host compared to my local setup which uses full emulation).

> Can you extract some logs from the CI somehow?? If it is
> hanging in the kernel there should be some
> soft lockup or RCU lockup related messages.

I think once we execute the test, vmtest does not track the console logs anymore, so we won’t see those. That should be fixable, but for now, I won’t be able to get more logs than you get from the UI currently.
> 
> I was talking about this with Kumar and we think that this test is
> hanging in the userspace in the following loop:
> 
> while (READ_ONCE(fexit_skel->bss->fentry_cnt) != 2);
> 
> Could it be that fentry_cnt is > 2 somehow before we reach this?? This
> is only a random guess though.
> 


Manu