From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f41.google.com ([74.125.83.41]:33932 "EHLO mail-pg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753430AbdCaUtf (ORCPT ); Fri, 31 Mar 2017 16:49:35 -0400 Received: by mail-pg0-f41.google.com with SMTP id 21so81405370pgg.1 for ; Fri, 31 Mar 2017 13:49:35 -0700 (PDT) From: Omar Sandoval To: Jens Axboe , linux-block@vger.kernel.org Cc: Christoph Hellwig , Keith Busch , Josef Bacik , kernel-team@fb.com Subject: [PATCH v3] blk-mq: remap queues when adding/removing hardware queues Date: Fri, 31 Mar 2017 13:48:35 -0700 Message-Id: <9753ebd0c51a9d49f110a6d0d00888170905d97a.1490993257.git.osandov@fb.com> In-Reply-To: <20170331204603.GB11462@vader> References: <20170331204603.GB11462@vader> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org From: Omar Sandoval 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 --- block/blk-mq.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 061fc2cc88d3..dbc0f2f745e3 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); -- 2.12.1