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Subject: Re: [PATCH BUGFIX/IMPROVEMENT 1/6] block, bfq: always inject I/O of
 queues blocked by wakers
To:     Paolo Valente <paolo.valente@linaro.org>
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jan Kara <jack@suse.cz>
References: <20210126105102.53102-1-paolo.valente@linaro.org>
 <20210126105102.53102-2-paolo.valente@linaro.org>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <23cc8281-a869-b260-ba0c-22127db2019b@kernel.dk>
Date:   Tue, 26 Jan 2021 09:17:55 -0700
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On 1/26/21 3:50 AM, Paolo Valente wrote:
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index 445cef9c0bb9..a83149407336 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -4487,9 +4487,15 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
>  			bfq_bfqq_busy(bfqq->bic->bfqq[0]) &&
>  			bfqq->bic->bfqq[0]->next_rq ?
>  			bfqq->bic->bfqq[0] : NULL;
> +		struct bfq_queue *blocked_bfqq =
> +			!hlist_empty(&bfqq->woken_list) ?
> +			container_of(bfqq->woken_list.first,
> +				     struct bfq_queue,
> +				     woken_list_node)
> +			: NULL;

hlist_first_entry_or_null?

-- 
Jens Axboe