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 49341C47409 for ; Tue, 10 Dec 2019 16:57:16 +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 1895920836 for ; Tue, 10 Dec 2019 16:57:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KehLtcNQ"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="tEVSmZ12" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1895920836 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=qYuRpzFdxaZs/Fy05Ws8PN3WHEaLff3Nx2ifX9FfkE0=; b=KehLtcNQHladrt 1lSC9cQAY9/SJnYXL/isTTtgNvqFSVDaAexvLjSD8zwI0k3SfF5SM2qHIlKMPXeU4Y0kR3U+San4j n+mPidFTbyHtQUALK1TSwVh42UNjn4LcQBAFOw5vrwRTIXT3hAd47CxljeHT+uVsNX7tRUaDL81LF onAVkATqz02OhOil2cZcNjFJ8rVtK4YnUMHnfPnJnEbnIvsHZDhW7JiRC8CBABe8Bvp4aH4gq4epA Ob1Y3UXoLovmjy4AqjAUamrrvVvYCy3GJhcSXLigy7i+5pB34CDhbZ/0rAwi3n0roLZZ+Bx4nnTak 2hfuagogaIKFBsLb+x0A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ieioz-0002yo-5l; Tue, 10 Dec 2019 16:57:13 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ieiow-0002yD-Ko for linux-nvme@lists.infradead.org; Tue, 10 Dec 2019 16:57:11 +0000 Received: from redsun51.ssa.fujisawa.hgst.com (unknown [199.255.47.7]) (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 E48662073D; Tue, 10 Dec 2019 16:57:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575997030; bh=ZcxpO8bo/3SkxK0u5kzWONkJwzLKEQB6kvgfzIqsjZU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tEVSmZ1207Xa69bb7TVYci8YvMibx4g5HKoJD3cxbSr04SAxQPDDIvGfttsaNJuYC fkWcNRnRECjo837qecb23paVqqNbF/DFMinLoD6uRPUc3CJEFC6dUqb7GdBWCQej2V /1THml0dKc81DxLsLg//qCRVhmCV7wpMAsjgiok8= Date: Wed, 11 Dec 2019 01:57:04 +0900 From: Keith Busch To: Daniel Wagner Subject: Re: [PATCHv3 1/4] nvme/pci: Disable interrupts for threaded handler Message-ID: <20191210165704.GB4424@redsun51.ssa.fujisawa.hgst.com> References: <20191209175622.1964-1-kbusch@kernel.org> <20191209175622.1964-2-kbusch@kernel.org> <20191210151257.2a36ny3yy5tdohda@beryllium.lan> <20191210152840.xgpibkzex6mhnmne@linutronix.de> <20191210155433.GA4424@redsun51.ssa.fujisawa.hgst.com> <20191210164456.mdeff7xepsnw532j@beryllium.lan> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191210164456.mdeff7xepsnw532j@beryllium.lan> 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-20191210_085710_707907_9EF1DE9D X-CRM114-Status: GOOD ( 17.46 ) 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: sagi@grimberg.me, Sebastian Andrzej Siewior , linux-nvme@lists.infradead.org, ming.lei@redhat.com, tglx@linutronix.de, hch@lst.de 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 Tue, Dec 10, 2019 at 05:44:56PM +0100, Daniel Wagner wrote: > On Wed, Dec 11, 2019 at 12:54:33AM +0900, Keith Busch wrote: > > On Tue, Dec 10, 2019 at 04:28:40PM +0100, Sebastian Andrzej Siewior wrote: > > > On 2019-12-10 16:12:57 [+0100], Daniel Wagner wrote: > > > > On Tue, Dec 10, 2019 at 02:56:19AM +0900, Keith Busch wrote: > > > > > static irqreturn_t nvme_irq_check(int irq, void *data) > > > > > { > > > > > struct nvme_queue *nvmeq = data; > > > > > - if (nvme_cqe_pending(nvmeq)) > > > > > - return IRQ_WAKE_THREAD; > > > > > - return IRQ_NONE; > > > > > + > > > > > + if (!nvme_cqe_pending(nvmeq)) > > > > > + return IRQ_NONE; > > > > > > > > IIRC, returning IRQ_NONE tells the irq core code that this is > > > > an unhandled IRQ. If the core sees too many of them it will print > > > > 'spurious irq' message. See __handle_irq_event_percpu, > > > > handle_irq_event_percpu and note_interrupt > > > > > > This is okay / intended. If nvme_cqe_pending() does not recognise that > > > this interrupt belongs to that device then it should return IRQ_NONE. > > > > Also note this patch doesn't change the condition when IRQ_NONE is > > returned. We've been doing that since nvme's beginning, as it really is > > a spurious interrupt from a likely malfunctioning device. > > Sure, I am just a bit confused how IRQ_NONE is used. The comment on > nvme_cqe_pending says "We read the CQE phase first to check if the > rest of the entry is valid", which I read as "check if we have > anything to do" and not "this irq doesn't belong to this queue". Those two interpretations sound like the same thing to me. :) The interrupt notifies the driver it has something to do, and reading the CQE phase confirms whether or not that's true. _______________________________________________ linux-nvme mailing list linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme