From: Tejun Heo <tj@kernel.org>
To: Qiurong Fang <fangqiurong@kylinos.cn>
Cc: void@manifault.com, arighi@nvidia.com, changwoo@igalia.com,
sched-ext@lists.linux.dev
Subject: Re: [PATCH] sched_ext: Delete sub-scheduler kobjects before releasing scx_enable_mutex
Date: Tue, 1 Sep 2026 09:56:51 -1000 [thread overview]
Message-ID: <apcuA5kzwRCu_P-V@slm.duckdns.org> (raw)
In-Reply-To: <20260901102240.2671888-1-fangqiurong@kylinos.cn>
On Tue, Sep 01, 2026 at 06:22:40PM +0800, Qiurong Fang wrote:
> From: fangqiurong <fangqiurong@kylinos.cn>
>
> The sub-scheduler disable path deletes the scheduler's kobjects after
> releasing scx_enable_mutex, while the root path deletes them before
> releasing it. A concurrent enable on the same cgroup can therefore hit
> kobject_add() with the same "sub-%llu" name still in the hierarchy and
> fail with -EEXIST, tearing down an otherwise healthy scheduler.
>
> Move the two kobject_del() calls above mutex_unlock() to match the root
> path.
Why is this a problem? The subsched hasn't been fully unloaded yet so if you
try to attach a new one, it's going to fail.
Thanks.
--
tejun
next prev parent reply other threads:[~2026-09-01 19:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-01 10:22 [PATCH] sched_ext: Delete sub-scheduler kobjects before releasing scx_enable_mutex Qiurong Fang
2026-09-01 19:56 ` Tejun Heo [this message]
2026-09-02 3:22 ` Qiurong Fang
2026-09-02 6:02 ` Tejun Heo
2026-09-01 20:17 ` Andrea Righi
-- strict thread matches above, loose matches on Subject: below --
2026-09-02 6:20 Qiurong Fang
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