From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74E12C77B7D for ; Sat, 13 May 2023 14:12:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231736AbjEMOMx (ORCPT ); Sat, 13 May 2023 10:12:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238993AbjEMOMx (ORCPT ); Sat, 13 May 2023 10:12:53 -0400 Received: from mail-qt1-x833.google.com (mail-qt1-x833.google.com [IPv6:2607:f8b0:4864:20::833]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05EA230C0 for ; Sat, 13 May 2023 07:12:52 -0700 (PDT) Received: by mail-qt1-x833.google.com with SMTP id d75a77b69052e-3f389c21fe8so39453331cf.3 for ; Sat, 13 May 2023 07:12:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1683987171; x=1686579171; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=mA6DdBwaCGj/+RZQvUf+gresNy3xMkdlzHnsTxDq2Eo=; b=imHyEZ08OxVy4dYc5daSWrtXJYiH3rp5LJyyUk2Li0pdKi6R0fUBIELqpjMFXJvYEk tfMMqYiY9+y0CuMhVyLgkEia2rDem1IJ/0/MX9zdNYsWEUbY/1g17QvAlyroS9OWXfOb fQUDQZUufjotEubcRYglsNfLYQrgsO2SSzG5E7eQvKHNt2sXLjK8OoTEqcVfeG1ntF+i tSIEYjeAw/krSz72d+fqMtqWKJUHEKd8Jnd6cLJirVkcDSvSCqeNghKs6/cxwWw6tYGT t/CxCY/gsuvDkS7Hmr985elMTr43i9ZaCU2epDOLPFxMInM+OTp0jvXcYbgzPkYBBcqV TVrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683987171; x=1686579171; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=mA6DdBwaCGj/+RZQvUf+gresNy3xMkdlzHnsTxDq2Eo=; b=O0E3hbZAN47xrWNlgU3n5nQr4SpfZ/xblhcUKOqFtaC9VeK22wUmCvoQjN0lSukU9O TreKVSsjQc4FwjsulL1rqCHtJyD7TICG3QMCRhgbLgMJ5LGHpM3srWCaEGNPAfzpdyLL jAH/j2TlBNKzkDePMVpyAQZ4ol6W/73WqFxHkQXo4Wokr31lyFJNXpy3OugYn0H1OV7J tdinun4R6BM609nZdvl0VJzdS6OaB+x+deI7D9bdgQS0G8BMMKXN6MnyxImhwLmqII5a BImZFAgB97j3expnaQD3wwelqaqA/Mfnqc59JilX9rl+p9DlpRghZv1U2KZswPi+xHar F1lg== X-Gm-Message-State: AC+VfDyz5XMxqy+xPV7Ak3VvLRF5iWAnRVNtWSzDvRtF33nF0z+kX/FN 6mpt3qyCAz3lO86Em+WhQWOaZPKORMU= X-Google-Smtp-Source: ACHHUZ5/8tEkur9GPqsG8uPhvAv+fDvYzCaqYEOysLvqBcImQKFRmqw7iCQjnDEAWZvPASBOSpDVaA== X-Received: by 2002:a05:622a:1807:b0:3f4:dc79:1a6e with SMTP id t7-20020a05622a180700b003f4dc791a6emr21553015qtc.19.1683987171028; Sat, 13 May 2023 07:12:51 -0700 (PDT) Received: from tian-Alienware-15-R4.fios-router.home (pool-173-77-254-84.nycmny.fios.verizon.net. [173.77.254.84]) by smtp.gmail.com with ESMTPSA id pc8-20020a05620a840800b0074de8d07052sm2617qkn.47.2023.05.13.07.12.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 13 May 2023 07:12:50 -0700 (PDT) From: Tian Lan To: axboe@kernel.dk, linux-block@vger.kernel.org Cc: Tian Lan Subject: [PATCH 1/1] blk-mq: fix blk_mq_hw_ctx active request accounting Date: Sat, 13 May 2023 10:12:34 -0400 Message-Id: <20230513141234.8395-1-tilan7663@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Tian Lan 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 --- block/blk-mq.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index 9c8dc70020bc..5b374fab169c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1593,6 +1593,9 @@ void blk_mq_put_rq_ref(struct request *rq) if (rq->end_io(rq, 0) == RQ_END_IO_FREE) blk_mq_free_request(rq); } else if (req_ref_put_and_test(rq)) { + if (rq->rq_flags & RQF_MQ_INFLIGHT) + __blk_mq_dec_active_requests(rq->mq_hctx) + __blk_mq_free_request(rq); } } -- 2.34.1