From: Frederic Weisbecker <frederic@kernel.org>
To: Waiman Long <longman@redhat.com>
Cc: "Chen Ridong" <chenridong@huaweicloud.com>,
"Tejun Heo" <tj@kernel.org>,
"Johannes Weiner" <hannes@cmpxchg.org>,
"Michal Koutný" <mkoutny@suse.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Juri Lelli" <juri.lelli@redhat.com>,
"Vincent Guittot" <vincent.guittot@linaro.org>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Ben Segall" <bsegall@google.com>, "Mel Gorman" <mgorman@suse.de>,
"Valentin Schneider" <vschneid@redhat.com>,
"Anna-Maria Behnsen" <anna-maria@linutronix.de>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Shuah Khan" <shuah@kernel.org>,
cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org
Subject: Re: [PATCH/for-next v4 2/4] cgroup/cpuset: Defer housekeeping_update() calls from CPU hotplug to workqueue
Date: Fri, 6 Feb 2026 23:28:53 +0100 [thread overview]
Message-ID: <aYZrJaIIbTX4E-nO@pavilion.home> (raw)
In-Reply-To: <20260206203712.1989610-3-longman@redhat.com>
Le Fri, Feb 06, 2026 at 03:37:10PM -0500, Waiman Long a écrit :
> The update_isolation_cpumasks() function can be called either directly
> from regular cpuset control file write with cpuset_full_lock() called
> or via the CPU hotplug path with cpus_write_lock and cpuset_mutex held.
>
> As we are going to enable dynamic update to the nozh_full housekeeping
> cpumask (HK_TYPE_KERNEL_NOISE) soon with the help of CPU hotplug,
> allowing the CPU hotplug path to call into housekeeping_update() directly
> from update_isolation_cpumasks() will likely cause deadlock. So we
Why do we need to call housekeeping_update() from hotplug? I would
expect it to be called only when cpuset control file are written since
housekeeping cpumask don't deal with online CPUs but with possible
CPUs.
Thanks.
--
Frederic Weisbecker
SUSE Labs
next prev parent reply other threads:[~2026-02-06 22:28 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-06 20:37 [PATCH/for-next v4 0/4] cgroup/cpuset: Fix partition related locking issues Waiman Long
2026-02-06 20:37 ` [PATCH/for-next v4 1/4] cgroup/cpuset: Clarify exclusion rules for cpuset internal variables Waiman Long
2026-02-09 3:41 ` Chen Ridong
2026-02-09 19:58 ` Waiman Long
2026-02-06 20:37 ` [PATCH/for-next v4 2/4] cgroup/cpuset: Defer housekeeping_update() calls from CPU hotplug to workqueue Waiman Long
2026-02-06 22:28 ` Frederic Weisbecker [this message]
2026-02-08 2:00 ` Waiman Long
2026-02-10 15:46 ` Frederic Weisbecker
2026-02-10 18:53 ` Waiman Long
2026-02-09 6:57 ` Chen Ridong
2026-02-06 20:37 ` [PATCH/for-next v4 3/4] cgroup/cpuset: Call housekeeping_update() without holding cpus_read_lock Waiman Long
2026-02-09 7:12 ` Chen Ridong
2026-02-09 20:29 ` Waiman Long
2026-02-10 1:29 ` Chen Ridong
2026-02-10 14:01 ` Waiman Long
2026-02-09 7:23 ` Chen Ridong
2026-02-09 20:20 ` Waiman Long
2026-02-10 1:39 ` Chen Ridong
2026-02-10 14:39 ` Waiman Long
2026-02-06 20:37 ` [PATCH/for-next v4 4/4] cgroup/cpuset: Eliminate some duplicated rebuild_sched_domains() calls Waiman Long
2026-02-09 7:53 ` Chen Ridong
2026-02-09 20:47 ` Waiman Long
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