From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Bart Van Assche , Hannes Reinecke , Johannes Thumshirn Subject: [PATCH 03/12] blk-mq: Explain when 'active_queues' is decremented Date: Thu, 17 Aug 2017 16:23:02 -0700 Message-Id: <20170817232311.25948-4-bart.vanassche@wdc.com> In-Reply-To: <20170817232311.25948-1-bart.vanassche@wdc.com> References: <20170817232311.25948-1-bart.vanassche@wdc.com> List-ID: It is nontrivial to derive from the blk-mq source code when blk_mq_tags.active_queues is decremented. Hence add a comment that explains this. Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Johannes Thumshirn --- block/blk-mq.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index f84d145490bf..b86d2cafc355 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -834,6 +834,10 @@ static void blk_mq_timeout_work(struct work_struct *work) } else { struct blk_mq_hw_ctx *hctx; + /* + * All requests finished (latest request timeout) seconds ago, + * so mark each hctx as idle. + */ queue_for_each_hw_ctx(q, hctx, i) { /* the hctx may be unmapped, so check it here */ if (blk_mq_hw_queue_mapped(hctx)) -- 2.14.0