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From: Sagi Grimberg <sagi@grimberg.me>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-nvme@lists.infradead.org,
	Keith Busch <keith.busch@intel.com>,
	linux-block@vger.kernel.org, Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH 4/5] nvme-tcp: support separate queue maps for read and write
Date: Tue, 11 Dec 2018 15:11:19 -0800	[thread overview]
Message-ID: <0b392933-9cdd-bfba-ea14-cdabc31a1dcb@grimberg.me> (raw)
In-Reply-To: <20181211134135.GD20614@lst.de>


>> +static int nvme_tcp_map_queues(struct blk_mq_tag_set *set)
>> +{
>> +	struct nvme_tcp_ctrl *ctrl = set->driver_data;
>> +	struct blk_mq_queue_map *map;
>> +
>> +	if (ctrl->ctrl.opts->nr_write_queues) {
>> +		/* separate read/write queues */
>> +		map = &set->map[HCTX_TYPE_DEFAULT];
>> +		map->queue_offset = 0;
>> +		map->nr_queues = ctrl->ctrl.opts->nr_write_queues;
>> +		blk_mq_map_queues(map);
> 
> Shouldn't this use nr_io_queues?

The intent is that HCTX_TYPE_READ will always use nr_io_queues and
HCTX_TYPE_DEFAULT will use nr_write_queues.. I'll document that
in the change log.

> Also I find the reused local map variable a little odd and not helpful
> for readability.  What about something like:
> 
> static int nvme_tcp_map_queues(struct blk_mq_tag_set *set)
> {
> 	struct nvme_tcp_ctrl *ctrl = set->driver_data;
> 
> 	set->map[HCTX_TYPE_DEFAULT].queue_offset = 0;
> 	set->map[HCTX_TYPE_DEFAULT].nr_queues = ctrl->ctrl.opts->nr_io_queues;
> 	blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
> 
> 	if (ctrl->ctrl.opts->nr_write_queues) {
> 		/* separate read/write queues */
> 		set->map[HCTX_TYPE_READ].queue_offset =
> 				ctrl->ctrl.opts->nr_io_queues;
> 		set->map[HCTX_TYPE_READ].nr_queues =
> 				ctrl->ctrl.opts->nr_write_queues;
> 	} else {
> 		/* mixed read/write queues */
> 		set->map[HCTX_TYPE_READ].queue_offset = 0;
> 		set->map[HCTX_TYPE_READ].nr_queues =
> 				ctrl->ctrl.opts->nr_io_queues;
> 	}
> 	blk_mq_map_queues(&set->map[HCTX_TYPE_READ]);
> 	return 0;
> }

That's better.. I'll update the patch with a change according to my
note above..

WARNING: multiple messages have this Message-ID (diff)
From: sagi@grimberg.me (Sagi Grimberg)
Subject: [PATCH 4/5] nvme-tcp: support separate queue maps for read and write
Date: Tue, 11 Dec 2018 15:11:19 -0800	[thread overview]
Message-ID: <0b392933-9cdd-bfba-ea14-cdabc31a1dcb@grimberg.me> (raw)
In-Reply-To: <20181211134135.GD20614@lst.de>


>> +static int nvme_tcp_map_queues(struct blk_mq_tag_set *set)
>> +{
>> +	struct nvme_tcp_ctrl *ctrl = set->driver_data;
>> +	struct blk_mq_queue_map *map;
>> +
>> +	if (ctrl->ctrl.opts->nr_write_queues) {
>> +		/* separate read/write queues */
>> +		map = &set->map[HCTX_TYPE_DEFAULT];
>> +		map->queue_offset = 0;
>> +		map->nr_queues = ctrl->ctrl.opts->nr_write_queues;
>> +		blk_mq_map_queues(map);
> 
> Shouldn't this use nr_io_queues?

The intent is that HCTX_TYPE_READ will always use nr_io_queues and
HCTX_TYPE_DEFAULT will use nr_write_queues.. I'll document that
in the change log.

> Also I find the reused local map variable a little odd and not helpful
> for readability.  What about something like:
> 
> static int nvme_tcp_map_queues(struct blk_mq_tag_set *set)
> {
> 	struct nvme_tcp_ctrl *ctrl = set->driver_data;
> 
> 	set->map[HCTX_TYPE_DEFAULT].queue_offset = 0;
> 	set->map[HCTX_TYPE_DEFAULT].nr_queues = ctrl->ctrl.opts->nr_io_queues;
> 	blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
> 
> 	if (ctrl->ctrl.opts->nr_write_queues) {
> 		/* separate read/write queues */
> 		set->map[HCTX_TYPE_READ].queue_offset =
> 				ctrl->ctrl.opts->nr_io_queues;
> 		set->map[HCTX_TYPE_READ].nr_queues =
> 				ctrl->ctrl.opts->nr_write_queues;
> 	} else {
> 		/* mixed read/write queues */
> 		set->map[HCTX_TYPE_READ].queue_offset = 0;
> 		set->map[HCTX_TYPE_READ].nr_queues =
> 				ctrl->ctrl.opts->nr_io_queues;
> 	}
> 	blk_mq_map_queues(&set->map[HCTX_TYPE_READ]);
> 	return 0;
> }

That's better.. I'll update the patch with a change according to my
note above..

  reply	other threads:[~2018-12-11 23:11 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-11 10:49 [PATCH 0/5] implement nvmf read/write queue maps Sagi Grimberg
2018-12-11 10:49 ` Sagi Grimberg
2018-12-11 10:49 ` [PATCH 1/5] blk-mq-rdma: pass in queue map to blk_mq_rdma_map_queues Sagi Grimberg
2018-12-11 10:49   ` Sagi Grimberg
2018-12-11 13:34   ` Christoph Hellwig
2018-12-11 13:34     ` Christoph Hellwig
2018-12-11 10:49 ` [PATCH 2/5] nvme-fabrics: add missing nvmf_ctrl_options documentation Sagi Grimberg
2018-12-11 10:49   ` Sagi Grimberg
2018-12-11 13:35   ` Christoph Hellwig
2018-12-11 13:35     ` Christoph Hellwig
2018-12-11 10:49 ` [PATCH 3/5] nvme-fabrics: allow user to set nr_write_queues for separate queue maps Sagi Grimberg
2018-12-11 10:49   ` Sagi Grimberg
2018-12-11 13:35   ` Christoph Hellwig
2018-12-11 13:35     ` Christoph Hellwig
2018-12-11 10:49 ` [PATCH 4/5] nvme-tcp: support separate queue maps for read and write Sagi Grimberg
2018-12-11 10:49   ` Sagi Grimberg
2018-12-11 13:41   ` Christoph Hellwig
2018-12-11 13:41     ` Christoph Hellwig
2018-12-11 23:11     ` Sagi Grimberg [this message]
2018-12-11 23:11       ` Sagi Grimberg
2018-12-11 10:49 ` [PATCH 5/5] nvme-rdma: support read/write queue separation Sagi Grimberg
2018-12-11 10:49   ` Sagi Grimberg
2018-12-11 13:42   ` Christoph Hellwig
2018-12-11 13:42     ` Christoph Hellwig
2018-12-11 10:49 ` [PATCH nvme-cli 6/5] fabrics: pass in nr_write_queues Sagi Grimberg
2018-12-11 10:49   ` Sagi Grimberg
2018-12-11 19:30   ` Keith Busch
2018-12-11 19:30     ` Keith Busch
2018-12-11 23:34     ` Sagi Grimberg
2018-12-11 23:34       ` Sagi Grimberg
2018-12-11 13:28 ` [PATCH 0/5] implement nvmf read/write queue maps Christoph Hellwig
2018-12-11 13:28   ` Christoph Hellwig

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