From: Waiman Long <longman@redhat.com>
To: "Michal Koutný" <mkoutny@suse.com>
Cc: Chen Ridong <chenridong@huawei.com>, Tejun Heo <tj@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>,
cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/2] cgroup/cpuset: Skip security check for hotplug induced v1 task migration
Date: Mon, 20 Apr 2026 13:44:39 -0400 [thread overview]
Message-ID: <ec115c35-4484-483e-bd06-9ee35bd98a93@redhat.com> (raw)
In-Reply-To: <7i2hhyijet57lfwvz3ipzlwrze3i6bm343evgpjixmj6bj44kl@rhszdi6rlycg>
On 4/20/26 1:08 PM, Michal Koutný wrote:
> On Tue, Mar 31, 2026 at 11:11:08AM -0400, Waiman Long <longman@redhat.com> wrote:
>> If a strict security policy is in place, however, the task migration
>> may fail when security_task_setscheduler() call in cpuset_can_attach()
>> returns a -EACCESS error.
> I think this should be generally safe to skip (since v2 doesn't consider
> the object of cpuset migration at all).
>
>> That will mean that those tasks will have no CPU to run on. The system
>> administrators will have to explicitly intervene to either add CPUs to
>> that cpuset or move the tasks elsewhere if they are aware of it.
> That "no CPU to run on" means the affected tasks would remain in
> schedule() indefinitely?
I believe the scheduler has a fallback mechanism in that particular
case, but it can be any CPU. So I don't think we should rely on that.
Cheers,
Longman
next prev parent reply other threads:[~2026-04-20 17:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-31 15:11 [PATCH v3 0/2] cgroup/cpuset: Fix v1 task migration failure from empty cpuset Waiman Long
2026-03-31 15:11 ` [PATCH v3 1/2] cgroup/cpuset: Simplify setsched decision check in task iteration loop of cpuset_can_attach() Waiman Long
2026-03-31 15:11 ` [PATCH v3 2/2] cgroup/cpuset: Skip security check for hotplug induced v1 task migration Waiman Long
2026-04-20 17:08 ` Michal Koutný
2026-04-20 17:44 ` Waiman Long [this message]
2026-04-21 14:04 ` Michal Koutný
2026-03-31 19:22 ` [PATCH v3 0/2] cgroup/cpuset: Fix v1 task migration failure from empty cpuset Tejun Heo
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