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Date: Mon, 10 Aug 2026 08:48:49 -1000
From: Tejun Heo <tj@kernel.org>
To: Usama Arif <usama.arif@linux.dev>
Cc: axboe@kernel.dk, cgroups@vger.kernel.org, josef@toxicpanda.com,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	shakeel.butt@linux.dev, hannes@cmpxchg.org, riel@surriel.com,
	kernel-team@meta.com
Subject: Re: [PATCH 1/3] blk-iolatency: clear delay state when freeing policy
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References: <20260806183742.946953-1-usama.arif@linux.dev>
 <20260806183742.946953-2-usama.arif@linux.dev>
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In-Reply-To: <20260806183742.946953-2-usama.arif@linux.dev>

On Thu, Aug 06, 2026 at 11:37:18AM -0700, Usama Arif wrote:
>  static void iolatency_pd_free(struct blkg_policy_data *pd)
>  {
> +	struct blkcg_gq *blkg = pd_to_blkg(pd);
> +
> +	/*
> +	 * Groups throttled as collateral have min_lat_nsec == 0, so
> +	 * iolatency_pd_offline() leaves their delay set.  Drop it here, where
> +	 * no in-flight bio can re-arm it via check_scale_change().
> +	 */
> +	if (blkg)

When can blkg be NULL here?

Thanks.

-- 
tejun