From: Tejun Heo <tj@kernel.org>
To: Usama Arif <usama.arif@linux.dev>
Cc: arighi@nvidia.com, bsegall@google.com, changwoo@igalia.com,
dietmar.eggemann@arm.com, etsal@meta.com, juri.lelli@redhat.com,
kprateek.nayak@amd.com, linux-kernel@vger.kernel.org,
mgorman@suse.de, mingo@redhat.com, peterz@infradead.org,
rostedt@goodmis.org, sched-ext@lists.linux.dev, tj@kernel.org,
vincent.guittot@linaro.org, void@manifault.com,
vschneid@redhat.com, yphbchou0911@gmail.com,
emil@etsalapatis.com, david.dai@linux.dev
Subject: Re: [PATCH] sched_ext: Avoid relocking DSQ during remote consumption
Date: Wed, 23 Sep 2026 08:59:15 -1000 [thread overview]
Message-ID: <15d491d4d4fb481941e8495d48b5c610@kernel.org> (raw)
In-Reply-To: <20260923140750.2128382-1-usama.arif@linux.dev>
Applied to sched_ext/for-7.4 with an unnecessary line break removed.
Possible follow-ups:
- The !dsq branch comment in scx_dispatch_dequeue() only mentions direct
dispatch as a source of holding_cpu. Remote consume now reaches it too.
Can you update the comment? The dsq branch comment also names
dispatch_to_local_dsq() as the racer when it's
unlink_dsq_and_switch_rq_lock().
- The remote local DSQ branch of move_task_between_dsqs() has the same
relock. Calling dispatch_dequeue_locked() before dropping src_dsq->lock
would avoid it. scx_bpf_dsq_move() isn't widely used, but it'd still be
nice.
Thanks.
--
tejun
prev parent reply other threads:[~2026-09-23 18:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-23 14:07 [PATCH] sched_ext: Avoid relocking DSQ during remote consumption Usama Arif
2026-09-23 18:59 ` Tejun Heo [this message]
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