From: Tejun Heo <tj@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: David Vernet <void@manifault.com>,
Andrea Righi <arighi@nvidia.com>,
Changwoo Min <changwoo@igalia.com>,
linux-kernel@vger.kernel.org, sched-ext@lists.linux.dev,
bpf@vger.kernel.org, Wen-Fang Liu <liuwenfang@honor.com>
Subject: Re: sched_ext: Fix SCX_KICK_WAIT to work reliably
Date: Wed, 22 Oct 2025 08:38:10 -1000 [thread overview]
Message-ID: <aPkkkp3foe1NoLfL@slm.duckdns.org> (raw)
In-Reply-To: <20251022080346.GH4067720@noisy.programming.kicks-ass.net>
On Wed, Oct 22, 2025 at 10:03:46AM +0200, Peter Zijlstra wrote:
> > while (smp_load_acquire(wait_pnt_seq) == pseqs[cpu])
> > cpu_relax();
>
> You could consider using:
>
> smp_cond_load_acquire(wait_pnt_seq, VAL !+ pseqs[cpu]);
>
> that's the fancy way of doing a spin wait and allows architectures to
> optimize (mostly arm64 at this point).
Will do. Thanks.
--
tejun
prev parent reply other threads:[~2025-10-22 18:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-21 21:03 [PATCHSET sched_ext/for-6.19] sched_ext: Fix SCX_KICK_WAIT reliability Tejun Heo
2025-10-21 21:03 ` sched_ext: Don't kick CPUs running higher classes Tejun Heo
2025-10-21 21:03 ` sched_ext: Fix SCX_KICK_WAIT to work reliably Tejun Heo
2025-10-22 7:43 ` Andrea Righi
2025-10-22 18:37 ` Tejun Heo
2025-10-22 19:25 ` Andrea Righi
2025-10-22 8:03 ` Peter Zijlstra
2025-10-22 18:38 ` Tejun Heo [this message]
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