Re: [PATCH v2] sched/deadline: Reset dl_server execution state on stop

[gmonaco]

On Wed, 2026-01-28 at 14:41 +0100, Andrea Righi wrote:
> Just to make sure we're testing the same thing, I'm currently using
> https://git.kernel.org/pub/scm/linux/kernel/git/arighi/linux.git,
> branch
> scx-dl-server.
> 
> I'm running this test inside virtme-ng:
>   $ vng -vb --config tools/testing/selftests/sched_ext/config
>   $ vng -v -- tools/testing/selftests/sched_ext/runner -t rt_stall

Well, that's a fun one, I could reproduce the same failure you
described in vng on another x86 box.

The arm box (bare metal) I used initially still passes just fine all 4
iterations of the test.


On the x86 box (vng) I tried different orders of iterations (where the
original is fair-ext-fair-ext) with and without the ext server active.

No ext-server: the ext iteration fails and breaks also fair (unlike the
arm64 box where the fair was intact)
ext-server active: a sequence fair-ext breaks both (like you observe).

I don't have time to look further into this right now, but it looks
like an interesting pattern.

Thanks,
Gabriele