From: Bart Van Assche <bvanassche@acm.org>
To: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, linux-scsi@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 04/14] blk-mq: pass in request/bio flags to queue mapping
Date: Mon, 29 Oct 2018 10:30:36 -0700 [thread overview]
Message-ID: <1540834236.196084.61.camel@acm.org> (raw)
In-Reply-To: <20181029163738.10172-5-axboe@kernel.dk>
On Mon, 2018-10-29 at 10:37 -0600, Jens Axboe wrote:
> @@ -400,9 +402,15 @@ void blk_mq_sched_insert_requests(struct request_queue *q,
> struct blk_mq_ctx *ctx,
> struct list_head *list, bool run_queue_async)
> {
> - struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
> - struct elevator_queue *e = hctx->queue->elevator;
> + struct blk_mq_hw_ctx *hctx;
> + struct elevator_queue *e;
> + struct request *rq;
> +
> + /* For list inserts, requests better be on the same hw queue */
> + rq = list_first_entry(list, struct request, queuelist);
> + hctx = blk_mq_map_queue(q, rq->cmd_flags, ctx->cpu);
Passing all request cmd_flags bits to blk_mq_map_queue() makes it possible
for that function to depend on every single cmd_flags bit even if different
requests have different cmd_flags. Have you considered to pass the hw_ctx
type only to blk_mq_map_queue() to avoid that that function would start
depending on other cmd_flags?
Additionally, what guarantees that all requests in queuelist have the same
hw_ctx type? If a later patch will guarantee that, please mention that in
the comment about list_first_entry().
Thanks,
Bart.
next prev parent reply other threads:[~2018-10-29 17:30 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-29 16:37 [PATCHSET v2 0/14] blk-mq: Add support for multiple queue maps Jens Axboe
2018-10-29 16:37 ` [PATCH 01/14] blk-mq: kill q->mq_map Jens Axboe
2018-10-29 16:46 ` Bart Van Assche
2018-10-29 16:51 ` Jens Axboe
2018-10-29 16:37 ` [PATCH 02/14] blk-mq: abstract out queue map Jens Axboe
2018-10-29 18:33 ` Bart Van Assche
2018-10-29 16:37 ` [PATCH 03/14] blk-mq: provide dummy blk_mq_map_queue_type() helper Jens Axboe
2018-10-29 17:22 ` Bart Van Assche
2018-10-29 17:27 ` Jens Axboe
2018-10-29 16:37 ` [PATCH 04/14] blk-mq: pass in request/bio flags to queue mapping Jens Axboe
2018-10-29 17:30 ` Bart Van Assche [this message]
2018-10-29 17:33 ` Jens Axboe
2018-10-29 16:37 ` [PATCH 05/14] blk-mq: allow software queue to map to multiple hardware queues Jens Axboe
2018-10-29 17:34 ` Bart Van Assche
2018-10-29 17:35 ` Jens Axboe
2018-10-29 16:37 ` [PATCH 06/14] blk-mq: add 'type' attribute to the sysfs hctx directory Jens Axboe
2018-10-29 17:40 ` Bart Van Assche
2018-10-29 16:37 ` [PATCH 07/14] blk-mq: support multiple hctx maps Jens Axboe
2018-10-29 18:15 ` Bart Van Assche
2018-10-29 19:24 ` Jens Axboe
2018-10-29 16:37 ` [PATCH 08/14] blk-mq: separate number of hardware queues from nr_cpu_ids Jens Axboe
2018-10-29 18:31 ` Bart Van Assche
2018-10-29 16:37 ` [PATCH 09/14] blk-mq: ensure that plug lists don't straddle hardware queues Jens Axboe
2018-10-29 19:27 ` Bart Van Assche
2018-10-29 19:30 ` Jens Axboe
2018-10-29 19:49 ` Jens Axboe
2018-10-30 8:08 ` Ming Lei
2018-10-30 17:22 ` Jens Axboe
2018-10-29 16:37 ` [PATCH 10/14] blk-mq: initial support for multiple queue maps Jens Axboe
2018-10-29 19:40 ` Bart Van Assche
2018-10-29 19:53 ` Jens Axboe
2018-10-29 20:00 ` Bart Van Assche
2018-10-29 20:09 ` Jens Axboe
2018-10-29 20:25 ` Bart Van Assche
2018-10-29 20:29 ` Jens Axboe
2018-10-29 16:37 ` [PATCH 11/14] irq: add support for allocating (and affinitizing) sets of IRQs Jens Axboe
2018-10-29 17:08 ` Thomas Gleixner
2018-10-29 17:09 ` Jens Axboe
2018-10-30 9:25 ` Ming Lei
2018-10-30 14:26 ` Keith Busch
2018-10-30 14:36 ` Jens Axboe
2018-10-30 14:45 ` Keith Busch
2018-10-30 14:53 ` Jens Axboe
2018-10-30 15:08 ` Keith Busch
2018-10-30 15:18 ` Jens Axboe
2018-10-30 16:02 ` Keith Busch
2018-10-30 16:42 ` Jens Axboe
2018-10-30 17:09 ` Jens Axboe
2018-10-30 17:22 ` Keith Busch
2018-10-30 17:33 ` Jens Axboe
2018-10-30 17:35 ` Keith Busch
2018-10-30 17:25 ` Thomas Gleixner
2018-10-30 17:34 ` Jens Axboe
2018-10-30 17:43 ` Jens Axboe
2018-10-30 17:46 ` Thomas Gleixner
2018-10-30 17:47 ` Jens Axboe
2018-10-29 16:37 ` [PATCH 12/14] nvme: utilize two queue maps, one for reads and one for writes Jens Axboe
2018-10-29 16:37 ` [PATCH 13/14] block: add REQ_HIPRI and inherit it from IOCB_HIPRI Jens Axboe
2018-10-29 16:37 ` [PATCH 14/14] nvme: add separate poll queue map Jens Axboe
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