Re: [PATCH v2 04/12] sched/core: Make __update_rq_clock() skip updates on UPDATED

[Tejun Heo <tj@kernel.org>]

Hello, Peter.

On Sat, Nov 07, 2026 at 12:59:17PM +0100, Peter Zijlstra wrote:
>  static void __update_rq_clock(struct rq *rq)
>  {
> +	bool update;
> +
>  	lockdep_assert_rq_held(rq);
>  
> +	update = !(rq->clock_update_flags & RQCF_NOP_MASK);
>  	rq->clock_update_flags |= RQCF_UPDATED;
>  
> -	if (!(rq->clock_update_flags & RQCF_ACT_SKIP)) {
> +	if (update) {

RQCF_UPDATED is cleared only by rq_pin_lock() and
double_rq_clock_clear_update(), so a path which takes the rq lock with
raw_spin_rq_lock() inherits it from the previous holder and its
update_rq_clock() is now silently skipped.

Previously, you said to clear on unlock. Why not do that? That'd be less
confusing overall.

Thanks.

--
tejun