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

[Jens Axboe]

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