Re: [PATCH v3] sched: Clarify WF_SYNC wakeup semantics

[Peter Zijlstra]

On Tue, Sep 22, 2026 at 02:57:05PM -0700, Shubhang Kaushik (Ampere) wrote:
> The synchronous waitqueue wakeup comments currently state that a
> synchronous wakee will not be migrated to another CPU. This is not
> guaranteed by the scheduler wakeup path.
> 
> WF_SYNC is an advisory hint that the caller expects the waker to
> schedule away soon. Scheduler classes may use it for placement or
> preemption, but callers must not rely on it to prevent migration,
> preserve CPU locality, or make the wakee run next.
> 
> Keep this contract next to the flag definition, remove the stale
> waitqueue wording, and make the locked helper refer to the unlocked
> variant.
> 
> ---
> Signed-off-by: Shubhang Kaushik (Ampere) <sh@xxxxxxxxxx>
> ---

Thanks!