Re: [PATCH RFC 10/14] block, bfq: add Early Queue Merge (EQM)

From	Jens Axboe <axboe@kernel.dk>
Newsgroups	linux.kernel
Subject	Re: [PATCH RFC 10/14] block, bfq: add Early Queue Merge (EQM)
Date	2017-03-15 18:00 +0100
Message-ID	<tlkrf-1Wi-3@gated-at.bofh.it> (permalink)
References	<thkpQ-3cO-5@gated-at.bofh.it> <thkpQ-3cO-11@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 03/04/2017 09:01 AM, Paolo Valente wrote:
> @@ -6330,7 +7012,41 @@ static void bfq_rq_enqueued(struct bfq_data *bfqd, struct bfq_queue *bfqq,
>  
>  static void __bfq_insert_request(struct bfq_data *bfqd, struct request *rq)
>  {
> -	struct bfq_queue *bfqq = RQ_BFQQ(rq);
> +	struct bfq_queue *bfqq = RQ_BFQQ(rq), *new_bfqq;
> +
> +	/*
> +	 * An unplug may trigger a requeue of a request from the device
> +	 * driver: make sure we are in process context while trying to
> +	 * merge two bfq_queues.
> +	 */
> +	if (!in_interrupt()) {

What's the reason for this? Don't use in_interrupt() to guide any of
your decision making here.

-- 
Jens Axboe

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Re: [PATCH RFC 10/14] block, bfq: add Early Queue Merge (EQM) Jens Axboe <axboe@kernel.dk> - 2017-03-15 18:00 +0100
  Re: [PATCH RFC 10/14] block, bfq: add Early Queue Merge (EQM) Paolo Valente <paolo.valente@linaro.org> - 2017-03-15 18:10 +0100
    Re: [PATCH RFC 10/14] block, bfq: add Early Queue Merge (EQM) Jens Axboe <axboe@kernel.dk> - 2017-03-15 22:10 +0100

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