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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB337C3A5A6 for ; Thu, 19 Sep 2019 14:13:09 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BEC6E205F4 for ; Thu, 19 Sep 2019 14:13:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="OaeiyamI"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="jN4dbbHT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BEC6E205F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8EAeLVLf59Nk4OuXIH9mVW4LR8jfzh5hK9uoe5InJoo=; b=OaeiyamI60okou szkEov+RwWD8NICRkoW0p5amGH+Fc0ePPq9QPaf8dWKOZnLjwMKZrvc+hCLrNrGSoYQZk7Llg+dgl RKYk9aNq79a2q95hp6yXNVUnrC31Y6pp0ND+7y/ZQYcAiaGYkG4jApftmilvp/d5ZCTOrdgrnmA0Y WJQMSOl4OfUK2v3bDq0ZXxwbM9ddEWupt4GNcVb+qNg41zWGXq9SYSBQIBY1XIn6MgHBBrAL8AzBE PAQtSti6hM8e42icPrhjdWhW9kxh4ZPspou68JxT4LpD744RjseyuG617oQp7gTPfnHxpihiu+AbW GhONXBETwbfLgJN2Rs6w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iAxBD-0000fq-3q; Thu, 19 Sep 2019 14:13:07 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iAxBA-0000fQ-5j for linux-nvme@lists.infradead.org; Thu, 19 Sep 2019 14:13:05 +0000 Received: from C02WT3WMHTD6 (unknown [8.36.226.102]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 329CD2067B; Thu, 19 Sep 2019 14:13:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568902383; bh=Fduf10OMcAOvnRZMP54/18uKfFU1Trz0JGIfeGeiB4A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jN4dbbHT21aYx902Chc1XXK8Kdi9Df4rkc3LIUIfNdMNrCDpcMm/HGWxuJVKpj41j UqzqSFg+JVY61WyyiE6LgTiPPxrk3kXuwgSfcumAmWgylc/3arkAL47IZGS0bxVKeY +VVd/nu3WZlz/ol+YKw71u/gNP84D1k5TAXs8uDk= Date: Thu, 19 Sep 2019 08:13:01 -0600 From: Keith Busch To: Bharat Kumar Gogada Subject: Re: NVMe Poll CQ on timeout Message-ID: <20190919141301.GA61660@C02WT3WMHTD6> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190919_071304_242270_070AA545 X-CRM114-Status: GOOD ( 13.28 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "keith.busch@intel.com" , Keith Busch , "linux-kernel@vger.kernel.org" , "linux-nvme@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Thu, Sep 19, 2019 at 01:47:50PM +0000, Bharat Kumar Gogada wrote: > Hi All, > > We are testing NVMe cards on ARM64 platform, the card uses MSI-X interrupts. > We are hitting following case in drivers/nvme/host/pci.c > /* > * Did we miss an interrupt? > */ > if (__nvme_poll(nvmeq, req->tag)) { > dev_warn(dev->ctrl.device, > "I/O %d QID %d timeout, completion polled\n", > req->tag, nvmeq->qid); > return BLK_EH_DONE; > } > > Can anyone tell when does nvme_timeout gets invoked ? Timeout is invoked when the driver didn't see a completion to a submitted command. > In what cases we see this interrupt miss ? That usually happens for one of two reasons: 1. The device didn't send any MSIx message for a CQE 2. The device sent the MSIx message before posting the CQE I've also seen h/w errata where the MSIx and CQE are re-ordered, which can also lead to this. A hardware trace would provide the most detailed view of what's happening. You might be able to infer if you carefully account for commands sent, interrupts received, and spurious interrupts detected. > We are seeing this issue only for reads with following fio command > fio --name=randwrite --ioengine=libaio --iodepth=1 --rw=randread --bs=128k --direct=0 \ > --size=128M --numjobs=3 --group_reporting --filename=/dev/nvme0n1 > > We are not seeing issue with --rw=randwrite for same size. > > Please let us know what can cause this issue. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme