From: Andrea Righi <arighi@nvidia.com>
To: Tejun Heo <tj@kernel.org>
Cc: David Vernet <void@manifault.com>,
Changwoo Min <changwoo@igalia.com>,
Joel Fernandes <joelagnelf@nvidia.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched_ext: Fix missing rq lock in scx_bpf_cpuperf_set()
Date: Thu, 27 Mar 2025 18:27:39 +0100 [thread overview]
Message-ID: <Z-WKi_aKOMgbzU1M@gpd3> (raw)
In-Reply-To: <Z-WIh6obKP-ygcsP@slm.duckdns.org>
On Thu, Mar 27, 2025 at 07:19:03AM -1000, Tejun Heo wrote:
> Hello,
>
> On Thu, Mar 27, 2025 at 06:15:09PM +0100, Andrea Righi wrote:
> > > If we don't want to do locked rq tracking, we can always use
> > > schedule_deferred() when any rq is locked too. That's a bit more expensive
> > > tho.
> >
> > Yeah, I'm a bit worried that locked rq tracking might introduce overhead to
> > all the scx callbacks, just to address this issue.
>
> All operaitons are already wrapped with SCX_CALL_OP() and updating per-cpu
> state (kf flags). It's unlikely that another percpu variable update is going
> to be noticeable.
Ack, I'll explore the locked rq tracking way then.
Thanks,
-Andrea
prev parent reply other threads:[~2025-03-27 17:27 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-25 14:00 [PATCH] sched_ext: Fix missing rq lock in scx_bpf_cpuperf_set() Andrea Righi
2025-03-27 0:24 ` Tejun Heo
2025-03-27 7:56 ` Andrea Righi
2025-03-27 9:53 ` Andrea Righi
2025-03-27 17:09 ` Tejun Heo
2025-03-27 17:15 ` Andrea Righi
2025-03-27 17:19 ` Tejun Heo
2025-03-27 17:27 ` Andrea Righi [this message]
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