Messages in this thread | | | Subject | Re: [PATCH v2 2/2] sched/fair: Trigger nohz.next_balance updates when a CPU goes NOHZ-idle | From | Dietmar Eggemann <> | Date | Tue, 20 Jul 2021 12:47:21 +0200 |
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On 19/07/2021 18:28, Valentin Schneider wrote: > On 19/07/21 17:24, Dietmar Eggemann wrote: >> On 19/07/2021 12:31, Valentin Schneider wrote:
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>>> * Ensures that if we miss the CPU, we must see the has_blocked >>> @@ -10531,6 +10540,8 @@ static void _nohz_idle_balance(struct rq *this_rq, unsigned int flags, >>> if (need_resched()) { >>> if (flags & NOHZ_STATS_KICK) >>> has_blocked_load = true; >> >> This looks weird now? 'has_blocked_load = true' vs >> 'WRITE_ONCE(nohz.needs_update, 1)'. >> > > Well, has_blocked_load lets us factorize the nohz.has_blocked write > (one is needed either when aborting or at the tail of the cpumask > iteration), whereas there is just a single write for nohz.needs_update > (when aborting).
You're right. Looks good then.
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