Re: [PATCH] sched_ext: don't BUG_ON a destroyed DSQ in process_deferred_reenq_users

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