Re: [patch V6 08/11] rseq: Reset slice extension when scheduled

[Mathieu Desnoyers]

On 2025-12-15 13:24, Thomas Gleixner wrote:
> When a time slice extension was granted in the need_resched() check on exit
> to user space, the task can still be scheduled out in one of the other
> pending work items. When it gets scheduled back in, and need_resched() is
> not set, then the stale grant would be preserved, which is just wrong.
>
> RSEQ already keeps track of that and sets TIF_RSEQ, which invokes the
> critical section and ID update mechanisms.
>
> Utilize them and clear the user space slice control member of struct rseq
> unconditionally within the existing user access sections. That's just an
> unconditional store more in that path.

Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com