From: Tejun Heo <tj@kernel.org>
To: Waiman Long <longman@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Aaron Tomlin <atomlin@atomlin.com>,
Valentin Schneider <vschneid@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 3/4] kernel/workqueue: Distinguish between general unbound and WQ_SYSFS cpumask changes
Date: Wed, 17 Jan 2024 09:42:31 -1000 [thread overview]
Message-ID: <Zagtpw-JQvdpFseh@slm.duckdns.org> (raw)
In-Reply-To: <72e4a971-96e5-44b7-b348-bbdb68e54b40@redhat.com>
Hello,
On Wed, Jan 17, 2024 at 02:32:34PM -0500, Waiman Long wrote:
> My impression is that changing the workqueue cpumask of ordered unbound
> workqueue may break the ordering guarantee momentarily. I was planning to
Ah, you're right. Changing cpumask would require changing the dfl_pwq and
that can introduce extra concurrency and break ordering and it's exempt from
unbound_cpumask updates. We likely need to add a mechanism for updating
ordered wq's so that the new pwq doesn't become until the previous one is
drained.
Thanks.
--
tejun
next prev parent reply other threads:[~2024-01-17 19:42 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-16 16:19 [RFC PATCH 0/4] Fix handling of rescuers affinity Juri Lelli
2024-01-16 16:19 ` [RFC PATCH 1/4] tools/workqueue: Add rescuers printing to wq_dump.py Juri Lelli
2024-01-16 16:19 ` [RFC PATCH 2/4] kernel/workqueue: Bind rescuer to unbound cpumask for WQ_UNBOUND Juri Lelli
2024-01-16 18:47 ` Tejun Heo
2024-01-17 6:30 ` Juri Lelli
2024-01-16 16:19 ` [RFC PATCH 3/4] kernel/workqueue: Distinguish between general unbound and WQ_SYSFS cpumask changes Juri Lelli
2024-01-16 18:57 ` Tejun Heo
2024-01-17 13:06 ` Juri Lelli
2024-01-17 17:12 ` Tejun Heo
2024-01-17 19:32 ` Waiman Long
2024-01-17 19:42 ` Tejun Heo [this message]
2024-01-18 12:52 ` Juri Lelli
2024-01-16 16:19 ` [RFC PATCH 4/4] kernel/workqueue: Let rescuers follow unbound wq " Juri Lelli
2024-01-17 3:56 ` Lai Jiangshan
2024-01-17 6:30 ` Juri Lelli
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