Re: [PATCH 2/2] selftests/sched_ext: Add test to validate ops.dequeue() semantics
From: Tejun Heo
Date: Mon Feb 09 2026 - 15:10:39 EST
Hello,
On Mon, Feb 09, 2026 at 08:17:24PM +0100, Andrea Righi wrote:
> Agreed. And just to be clear, for the purpose of triggering ops.dequeue(),
> **all** direct dispatches from ops.select_cpu() should be consistently
> ignored, including dispatches to user DSQs. I'll update this behavior in
> the next version, because this one treats direct dispatches to user DSQs
> from ops.select_cpu() as if the task is in the scheduler's custody, which
> shouldn't be the case for consistency.
I'm not sure about that. ops.select_cpu() doing direct dispatch is just a
shortcut and should be treated like the same operation being done at the
head of ops.enqueue(). That's what's happening semantically and I think we
should stick with what's happening underneath - ie. make ops.select_cpu()'s
shortcut the special case, not whether tasks in a user DSQ get ops.dequeue()
or not.
Thanks.
--
tejun