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Date: Mon, 06 Jul 2026 13:40:42 -1000
Message-ID: <ecef28b2d5677149e2a5ce187e2dcd86@kernel.org>
From: Tejun Heo <tj@kernel.org>
To: sashiko-bot@kernel.org
Cc: sched-ext@lists.linux.dev
Subject: Re: [PATCH v2 sched_ext/for-7.3 17/36] sched_ext: RCU-protect the sub-sched tree's children/sibling lists
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On Mon, 06 Jul 2026 02:08:10 +0000, sashiko-bot wrote:
> - [High] Incomplete inheritance of bypass state in scx_link_sched() leaves the new sub-scheduler in a broken bypass mode.
> - [High] RCU-001: Remove Before Reclaim Ordering Violation in scheduler disable paths.

17-1 (bypass inherit): fixed for v3. Instead of inheriting bypass_depth
(which the per-cpu bypass flag never actually sets), scx_link_sched() now
rejects linking under a bypassing ancestor with -EBUSY.

17-2 (remove-before-reclaim): false positive. @sch and its pshards are freed
by scx_sched_free_rcu_work() (call_rcu, a full grace period after
list_del_rcu), and no walker calls a BPF op on a dying sub. The ordering is
fine, not a UAF.