Re: [PATCH v25 1/9] sched: Make class_schedulers avoid pushing current, and get rid of proxy_tag_curr()

John Stultz
2026-03-17T06:04:45Z

On Mon, Mar 16, 2026 at 10:41 PM K Prateek Nayak <kprateek.nayak@amd.com> wrote:
> On 3/17/2026 10:19 AM, John Stultz wrote:
> >
> > I guess adding a new helper function to manually do the
> > put_prev/set_next could be added to the top level __schedule() logic
> > in the (prev != next) case, though we'll have to preserve the
> > prev_donor on the stack probably.
>
> That seems like the best option to me too.
>
> Also, deadline, RT, fair, and idle don't really care about the "next"
> argument of put_prev_task() and the only one that does care is
> put_prev_task_scx() to call switch_class() callback so putting it as
> either NULL or "rq->donor" should be safe.

Ack.
Here's the change I'm testing tonight (against 6.18):
https://github.com/johnstultz-work/linux-dev/commit/0cc72a4923143f496e33711cbcc1afdf6d861ca6

Feel free to suggest a better name for the helper function. It feels a
little clunky (and sort of sad right after getting rid of the clunky
proxy_tag_curr(), to re-add something so similar).

Thanks again for your thoughtful feedback!
-john