On Mon, 2017-06-05 at 23:59 +0800, Ming Lei wrote:
> +static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
> + struct request *rq,
> + blk_qc_t *cookie, bool may_sleep)
> {
> struct request_queue *q = rq->q;
> struct blk_mq_queue_data bd = {
> .rq = rq,
> .last = true,
> };
> - struct blk_mq_hw_ctx *hctx;
> blk_qc_t new_cookie;
> int ret;
> + bool run_queue = true;
> +
> + if (blk_mq_hctx_stopped(hctx)) {
> + run_queue = false;
> + goto insert;
> + }
>
> if (q->elevator)
> goto insert;
>
> - if (!blk_mq_get_driver_tag(rq, &hctx, false))
> + if (!blk_mq_get_driver_tag(rq, NULL, false))
> goto insert;
>
> new_cookie = request_to_qc_t(hctx, rq);
> @@ -1439,7 +1445,7 @@ static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie,
>
> __blk_mq_requeue_request(rq);
> insert:
> - blk_mq_sched_insert_request(rq, false, true, false, may_sleep);
> + blk_mq_sched_insert_request(rq, false, run_queue, false, may_sleep);
> }
>
> static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
> @@ -1447,7 +1453,7 @@ static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
> {
> if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
> rcu_read_lock();
> - __blk_mq_try_issue_directly(rq, cookie, false);
> + __blk_mq_try_issue_directly(hctx, rq, cookie, false);
> rcu_read_unlock();
> } else {
> unsigned int srcu_idx;
> @@ -1455,7 +1461,7 @@ static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
> might_sleep();
>
> srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu);
> - __blk_mq_try_issue_directly(rq, cookie, true);
> + __blk_mq_try_issue_directly(hctx, rq, cookie, true);
> srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx);
> }
> }
Hello Ming,
It seems like you are assuming that the hardware queue of the rq argument
passed to __blk_mq_try_issue_directly() matches the hctx argument? Sorry
but I think that's an incorrect assumption. Please have a look at the
following code in blk_mq_make_request():
if (same_queue_rq)
blk_mq_try_issue_directly(data.hctx, same_queue_rq,
&cookie);
Bart.
