From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C04ED512 for ; Mon, 12 Jun 2023 10:51:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0523FC4339C; Mon, 12 Jun 2023 10:51:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1686567061; bh=0cyYx0L4udcF3sFr86PyDu7MhaotetV0bmOuV3Kqb0k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fCHrBE5w4OGWwawcKZPOcoA63xGrjzDegzG18hwLHVvrzxJGmGCe4p/LNIwWvf3Os Yf6C5aeIe3O7ZKKMMocy5aKrsgBb2k4jxniMabNcqMuZ1xbmtXjr5NjY+8QF+j6CZi QYrq2ZaruQWlzslH22Yq5gQ1ppHUGyYohbQi7Oq8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tian Lan , Ming Lei , Jens Axboe , Sasha Levin Subject: [PATCH 6.3 135/160] blk-mq: fix blk_mq_hw_ctx active request accounting Date: Mon, 12 Jun 2023 12:27:47 +0200 Message-ID: <20230612101721.246495166@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230612101715.129581706@linuxfoundation.org> References: <20230612101715.129581706@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Tian Lan [ Upstream commit ddad59331a4e16088468ca0ad228a9fe32d7955a ] The nr_active counter continues to increase over time which causes the blk_mq_get_tag to hang until the thread is rescheduled to a different core despite there are still tags available. kernel-stack INFO: task inboundIOReacto:3014879 blocked for more than 2 seconds Not tainted 6.1.15-amd64 #1 Debian 6.1.15~debian11 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:inboundIOReacto state:D stack:0 pid:3014879 ppid:4557 flags:0x00000000 Call Trace: __schedule+0x351/0xa20 scheduler+0x5d/0xe0 io_schedule+0x42/0x70 blk_mq_get_tag+0x11a/0x2a0 ? dequeue_task_stop+0x70/0x70 __blk_mq_alloc_requests+0x191/0x2e0 kprobe output showing RQF_MQ_INFLIGHT bit is not cleared before __blk_mq_free_request being called. 320 320 kworker/29:1H __blk_mq_free_request rq_flags 0x220c0 in-flight 1 b'__blk_mq_free_request+0x1 [kernel]' b'bt_iter+0x50 [kernel]' b'blk_mq_queue_tag_busy_iter+0x318 [kernel]' b'blk_mq_timeout_work+0x7c [kernel]' b'process_one_work+0x1c4 [kernel]' b'worker_thread+0x4d [kernel]' b'kthread+0xe6 [kernel]' b'ret_from_fork+0x1f [kernel]' Signed-off-by: Tian Lan Fixes: 2e315dc07df0 ("blk-mq: grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter") Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20230513221227.497327-1-tilan7663@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-mq.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index ae08c4936743d..f2e2ffd135baf 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -717,6 +717,10 @@ static void __blk_mq_free_request(struct request *rq) blk_crypto_free_request(rq); blk_pm_mark_last_busy(rq); rq->mq_hctx = NULL; + + if (rq->rq_flags & RQF_MQ_INFLIGHT) + __blk_mq_dec_active_requests(hctx); + if (rq->tag != BLK_MQ_NO_TAG) blk_mq_put_tag(hctx->tags, ctx, rq->tag); if (sched_tag != BLK_MQ_NO_TAG) @@ -728,15 +732,11 @@ static void __blk_mq_free_request(struct request *rq) void blk_mq_free_request(struct request *rq) { struct request_queue *q = rq->q; - struct blk_mq_hw_ctx *hctx = rq->mq_hctx; if ((rq->rq_flags & RQF_ELVPRIV) && q->elevator->type->ops.finish_request) q->elevator->type->ops.finish_request(rq); - if (rq->rq_flags & RQF_MQ_INFLIGHT) - __blk_mq_dec_active_requests(hctx); - if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) laptop_io_completion(q->disk->bdi); -- 2.39.2