From: Tejun Heo <tj@kernel.org>
To: Tao Cui <cui.tao@linux.dev>
Cc: Tao Cui <cuitao@kylinos.cn>,
void@manifault.com, arighi@nvidia.com, changwoo@igalia.com,
mingo@redhat.com, peterz@infradead.org,
sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org,
bpf@vger.kernel.org
Subject: Re: [PATCH] sched_ext: don't BUG_ON a destroyed DSQ in process_deferred_reenq_users
Date: Fri, 14 Aug 2026 08:56:54 -1000 [thread overview]
Message-ID: <f3a7965cc9d6527de793fdda816b6b63@kernel.org> (raw)
In-Reply-To: <20260811075913.344033-1-cui.tao@linux.dev>
Hello,
On Tue, Aug 11, 2026 at 03:59:12PM +0800, Tao Cui wrote:
> - BUG_ON(dsq->id & SCX_DSQ_FLAG_BUILTIN);
> + /* destroy_dsq() may race and invalidate @dsq; skip */
> + if (unlikely(dsq->id & SCX_DSQ_FLAG_BUILTIN))
> + continue;
Nice catch, but this also swallows states which can never occur
legitimately. The only builtin-flagged value that can show up here is
SCX_DSQ_INVALID from destroy_dsq(). Let's keep the BUG_ON for everything
else:
/* destroy_dsq() may have raced and invalidated @dsq, nothing to reenq */
if (unlikely(dsq->id == SCX_DSQ_INVALID))
continue;
BUG_ON(dsq->id & SCX_DSQ_FLAG_BUILTIN);
Can you please spin v2? Also, please capitalize the subject after the
prefix ("Don't ...") and remove the blank line between the tags.
Thanks.
--
tejun
next prev parent reply other threads:[~2026-08-14 18:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-11 7:59 [PATCH] sched_ext: don't BUG_ON a destroyed DSQ in process_deferred_reenq_users Tao Cui
2026-08-14 18:56 ` Tejun Heo [this message]
2026-08-15 0:01 ` Tao Cui
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