Re: [PATCH v2] sched_ext: improve WAKE_SYNC behavior for default idle CPU selection

From: Tejun Heo
Date: Fri Oct 18 2024 - 16:26:47 EST


On Fri, Oct 18, 2024 at 08:09:51PM +0200, Andrea Righi wrote:
> In the sched_ext built-in idle CPU selection logic, when handling a
> WF_SYNC wakeup, we always attempt to migrate the task to the waker's
> CPU, as the waker is expected to yield the CPU after waking the task.
>
> However, it may be preferable to keep the task on its previous CPU if
> the waker's CPU is cache-affine.
>
> The same approach is also used by the fair class and in other scx
> schedulers, like scx_rusty and scx_bpfland.
>
> Therefore, apply the same logic to the built-in idle CPU selection
> policy as well.
>
> Signed-off-by: Andrea Righi <andrea.righi@xxxxxxxxx>

Applied to sched_ext/for-6.13.

Thanks.

--
tejun