From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f41.google.com ([74.125.83.41]:36443 "EHLO mail-pg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751649AbdDCVnI (ORCPT ); Mon, 3 Apr 2017 17:43:08 -0400 Received: by mail-pg0-f41.google.com with SMTP id g2so130864338pge.3 for ; Mon, 03 Apr 2017 14:43:08 -0700 (PDT) From: Omar Sandoval To: Jens Axboe , linux-block@vger.kernel.org Cc: kernel-team@fb.com Subject: [PATCH 4/5] blk-mq: remap queues when adding/removing hardware queues Date: Mon, 3 Apr 2017 14:42:04 -0700 Message-Id: <4ab0628bf930d80f618609caa564a3a036b6cbc0.1491254827.git.osandov@fb.com> In-Reply-To: References: In-Reply-To: References: 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") Reviewed-by: Keith Busch 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 477951d10cc9..b49fdfde7e06 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2483,6 +2483,14 @@ 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 @@ -2537,10 +2545,7 @@ 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; @@ -2632,6 +2637,7 @@ 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); -- 2.12.2