From: Omar Sandoval <osandov@osandov.com>
To: Jens Axboe <axboe@fb.com>, linux-block@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>,
Keith Busch <keith.busch@intel.com>, Josef Bacik <jbacik@fb.com>,
kernel-team@fb.com
Subject: [PATCH v2] blk-mq: remap queues when adding/removing hardware queues
Date: Fri, 31 Mar 2017 13:43:41 -0700 [thread overview]
Message-ID: <c14ba78ad1898eef31415e86383e3b5a8ad082b9.1490992756.git.osandov@fb.com> (raw)
In-Reply-To: <20170331204428.GM20181@localhost.localdomain>
From: Omar Sandoval <osandov@fb.com>
blk_mq_update_nr_hw_queues() used to remap hardware queues, which is the
behavior that drivers expect. However, commit 4e68a011428a changed
blk_mq_queue_reinit() to not remap queues for the case of CPU
hotplugging, inadvertently making blk_mq_update_nr_hw_queues() not remap
queues as well. This breaks, for example, NBD's multi-connection mode,
leaving the added hardware queues unused. Fix it by making
blk_mq_update_nr_hw_queues() explicitly remap the queues.
Fixes: 4e68a011428a ("blk-mq: don't redistribute hardware queues on a CPU hotplug event")
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
block/blk-mq.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 061fc2cc88d3..70fa2b0d385a 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2478,6 +2478,14 @@ static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
return 0;
}
+static int blk_mq_update_queue_map(struct blk_mq_tag_set *set)
+{
+ if (set->ops->map_queues)
+ return set->ops->map_queues(set);
+ else
+ return blk_mq_map_queues(set);
+}
+
/*
* Alloc a tag set to be associated with one or more request queues.
* May fail with EINVAL for various error conditions. May adjust the
@@ -2532,10 +2540,7 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
if (!set->mq_map)
goto out_free_tags;
- if (set->ops->map_queues)
- ret = set->ops->map_queues(set);
- else
- ret = blk_mq_map_queues(set);
+ ret = blk_mq_update_queue_map(set);
if (ret)
goto out_free_mq_map;
@@ -2627,6 +2632,7 @@ void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
blk_mq_freeze_queue(q);
set->nr_hw_queues = nr_hw_queues;
+ blk_mq_update_queue_map(set);
list_for_each_entry(q, &set->tag_list, tag_set_list) {
blk_mq_realloc_hw_ctxs(set, q);
blk_mq_queue_reinit(q, cpu_online_mask);
@@ -2634,6 +2640,7 @@ void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
list_for_each_entry(q, &set->tag_list, tag_set_list)
blk_mq_unfreeze_queue(q);
+
}
EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
--
2.12.1
next prev parent reply other threads:[~2017-03-31 20:44 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-31 18:59 [PATCH] blk-mq: remap queues when adding/removing hardware queues Omar Sandoval
2017-03-31 19:01 ` Omar Sandoval
2017-03-31 20:30 ` Keith Busch
2017-03-31 20:30 ` Omar Sandoval
2017-03-31 20:44 ` Keith Busch
2017-03-31 20:43 ` Omar Sandoval [this message]
2017-03-31 20:46 ` [PATCH v2] " Omar Sandoval
2017-03-31 20:48 ` [PATCH v3] " Omar Sandoval
2017-03-31 21:09 ` Keith Busch
2017-04-04 6:24 ` Christoph Hellwig
2017-04-05 12:01 ` Sagi Grimberg
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