From: Jens Axboe <axboe@kernel.dk>
To: linux-block@vger.kernel.org, linux-nvme@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 08/16] blk-mq: separate number of hardware queues from nr_cpu_ids
Date: Tue, 30 Oct 2018 12:32:44 -0600 [thread overview]
Message-ID: <20181030183252.17857-9-axboe@kernel.dk> (raw)
In-Reply-To: <20181030183252.17857-1-axboe@kernel.dk>
With multiple maps, nr_cpu_ids is no longer the maximum number of
hardware queues we support on a given devices. The initializer of
the tag_set can have set ->nr_hw_queues larger than the available
number of CPUs, since we can exceed that with multiple queue maps.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/blk-mq.c | 28 +++++++++++++++++++++-------
1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 9d6e2f6f8ee9..1ca48cf3bbc7 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2668,6 +2668,19 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
mutex_unlock(&q->sysfs_lock);
}
+/*
+ * Maximum number of hardware queues we support. For single sets, we'll never
+ * have more than the CPUs (software queues). For multiple sets, the tag_set
+ * user may have set ->nr_hw_queues larger.
+ */
+static unsigned int nr_hw_queues(struct blk_mq_tag_set *set)
+{
+ if (set->nr_maps == 1)
+ return nr_cpu_ids;
+
+ return max(set->nr_hw_queues, nr_cpu_ids);
+}
+
struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
struct request_queue *q)
{
@@ -2687,7 +2700,8 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
/* init q->mq_kobj and sw queues' kobjects */
blk_mq_sysfs_init(q);
- q->queue_hw_ctx = kcalloc_node(nr_cpu_ids, sizeof(*(q->queue_hw_ctx)),
+ q->nr_queues = nr_hw_queues(set);
+ q->queue_hw_ctx = kcalloc_node(q->nr_queues, sizeof(*(q->queue_hw_ctx)),
GFP_KERNEL, set->numa_node);
if (!q->queue_hw_ctx)
goto err_percpu;
@@ -2699,7 +2713,6 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
INIT_WORK(&q->timeout_work, blk_mq_timeout_work);
blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);
- q->nr_queues = nr_cpu_ids;
q->tag_set = set;
q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
@@ -2889,12 +2902,13 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
set->queue_depth = min(64U, set->queue_depth);
}
/*
- * There is no use for more h/w queues than cpus.
+ * There is no use for more h/w queues than cpus if we just have
+ * a single map
*/
- if (set->nr_hw_queues > nr_cpu_ids)
+ if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids)
set->nr_hw_queues = nr_cpu_ids;
- set->tags = kcalloc_node(nr_cpu_ids, sizeof(struct blk_mq_tags *),
+ set->tags = kcalloc_node(nr_hw_queues(set), sizeof(struct blk_mq_tags *),
GFP_KERNEL, set->numa_node);
if (!set->tags)
return -ENOMEM;
@@ -2937,7 +2951,7 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
{
int i, j;
- for (i = 0; i < nr_cpu_ids; i++)
+ for (i = 0; i < nr_hw_queues(set); i++)
blk_mq_free_map_and_requests(set, i);
for (j = 0; j < set->nr_maps; j++) {
@@ -3069,7 +3083,7 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
lockdep_assert_held(&set->tag_list_lock);
- if (nr_hw_queues > nr_cpu_ids)
+ if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids)
nr_hw_queues = nr_cpu_ids;
if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues)
return;
--
2.17.1
next prev parent reply other threads:[~2018-10-30 18:34 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-30 18:32 [PATCHSET v3 0/16] blk-mq: Add support for multiple queue maps Jens Axboe
2018-10-30 18:32 ` [PATCH 01/16] blk-mq: kill q->mq_map Jens Axboe
2018-10-31 0:28 ` Sagi Grimberg
2018-10-30 18:32 ` [PATCH 02/16] blk-mq: abstract out queue map Jens Axboe
2018-10-31 0:31 ` Sagi Grimberg
2018-10-31 14:17 ` Jens Axboe
2018-10-30 18:32 ` [PATCH 03/16] blk-mq: provide dummy blk_mq_map_queue_type() helper Jens Axboe
2018-10-31 0:32 ` Sagi Grimberg
2018-10-30 18:32 ` [PATCH 04/16] blk-mq: pass in request/bio flags to queue mapping Jens Axboe
2018-10-31 0:37 ` Sagi Grimberg
2018-10-31 14:18 ` Jens Axboe
2018-10-30 18:32 ` [PATCH 05/16] blk-mq: allow software queue to map to multiple hardware queues Jens Axboe
2018-10-31 0:49 ` Sagi Grimberg
2018-10-31 14:19 ` Jens Axboe
2018-10-30 18:32 ` [PATCH 06/16] blk-mq: add 'type' attribute to the sysfs hctx directory Jens Axboe
2018-10-31 0:53 ` Sagi Grimberg
2018-10-31 14:21 ` Jens Axboe
2018-11-01 21:59 ` Omar Sandoval
2018-11-01 22:50 ` Jens Axboe
2018-10-30 18:32 ` [PATCH 07/16] blk-mq: support multiple hctx maps Jens Axboe
2018-10-31 0:59 ` Sagi Grimberg
2018-10-31 14:23 ` Jens Axboe
2018-10-30 18:32 ` Jens Axboe [this message]
2018-10-31 1:00 ` [PATCH 08/16] blk-mq: separate number of hardware queues from nr_cpu_ids Sagi Grimberg
2018-10-30 18:32 ` [PATCH 09/16] blk-mq: cache request hardware queue mapping Jens Axboe
2018-10-31 1:01 ` Sagi Grimberg
2018-11-01 9:27 ` Hannes Reinecke
2018-11-01 12:22 ` Jens Axboe
2018-10-30 18:32 ` [PATCH 10/16] blk-mq: cleanup and improve list insertion Jens Axboe
2018-10-31 1:03 ` Sagi Grimberg
2018-11-01 9:28 ` Hannes Reinecke
2018-10-30 18:32 ` [PATCH 11/16] blk-mq: improve plug list sorting Jens Axboe
2018-10-31 1:04 ` Sagi Grimberg
2018-11-01 9:30 ` Hannes Reinecke
2018-10-30 18:32 ` [PATCH 12/16] blk-mq: initial support for multiple queue maps Jens Axboe
2018-10-31 1:14 ` Sagi Grimberg
2018-10-30 18:32 ` [PATCH 13/16] irq: add support for allocating (and affinitizing) sets of IRQs Jens Axboe
2018-10-31 1:17 ` Sagi Grimberg
2018-11-02 14:37 ` Ming Lei
2018-11-02 15:09 ` Keith Busch
2018-11-03 2:22 ` Ming Lei
2018-10-30 18:32 ` [PATCH 14/16] nvme: utilize two queue maps, one for reads and one for writes Jens Axboe
2018-10-31 1:57 ` Sagi Grimberg
2018-10-31 14:32 ` Jens Axboe
2018-10-30 18:32 ` [PATCH 15/16] block: add REQ_HIPRI and inherit it from IOCB_HIPRI Jens Axboe
2018-10-31 1:58 ` Sagi Grimberg
2018-10-30 18:32 ` [PATCH 16/16] nvme: add separate poll queue map Jens Axboe
2018-10-30 18:35 ` [PATCHSET v3 0/16] blk-mq: Add support for multiple queue maps Keith Busch
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181030183252.17857-9-axboe@kernel.dk \
--to=axboe@kernel.dk \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvme@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).