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,URIBL_BLOCKED, 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 07F34C3F2CD for ; Thu, 5 Mar 2020 15:15:37 +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 CAC622070E for ; Thu, 5 Mar 2020 15:15:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KoDTHr07"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="rtV+cSrB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CAC622070E 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=Di02vBPFzE5nCLOp34srhj8Ib+u0vwkuezyeBMvAOAE=; b=KoDTHr07X6erRx Fh0aPr31HGtIOakToYGeXRM/SDRNeivcrondwWcFs+MfNrcWrdzVLFdB27BPfTJhvMWD28uJ2bXuZ ubogCCKwvjibKW5EFlNMMKaS+SLVti8lHbUjbRiM7+qPZJ5G75pEC/oiA6795gdWaqL3LbPrqqjBF ZiIyFcM66E3EYvePsDqmZ92e5FZ3GTM8MQ2wBw/iHvzg3LZ5phcQqVsQOhGI2RqKYFsyad56vQnGU rMEC8efA8xK9mOhmOiJaaIRxAM747fy0HiB25URprVp9EtKf/G8F1yC+at8dhcCyKCJrzQgX4I4Qd BPm+bK1xy2kZvL6SnPag==; 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 1j9sDi-0000N8-Cy; Thu, 05 Mar 2020 15:15:30 +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 1j9sDf-0000Mb-Gz for linux-nvme@lists.infradead.org; Thu, 05 Mar 2020 15:15:28 +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 EFCD92070E; Thu, 5 Mar 2020 15:15:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583421326; bh=ItX38qm1pswyptVVy91LZsyl5zmL/0WJQBmFJVkJaoI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rtV+cSrBl1dF+ETv5i743nj08XLXvdU8UiMDY/nKX4KZrp2ra4/lcyU8axaJ+2Scq c4bgKeyKr9o3OEDe/kqVHJVhRo5vSKZBPyoU32cXSGJ6UY0jJ9KGCtfpuuu6gDxJdB uTAlI1KQ4bmHDQmtBfUAzQlLwWAmH0FJjlQM37CU= Date: Fri, 6 Mar 2020 00:15:23 +0900 From: Keith Busch To: Dongli Zhang Subject: Re: [PATCHv2 2/3] nvme-pci: Remove two-pass completions Message-ID: <20200305151523.GA28317@redsun51.ssa.fujisawa.hgst.com> References: <20200304181246.481835-1-kbusch@kernel.org> <20200304181246.481835-3-kbusch@kernel.org> 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-20200305_071527_587769_3DD27E18 X-CRM114-Status: GOOD ( 12.34 ) 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: bijan.mottahedeh@oracle.com, hch@lst.de, linux-nvme@lists.infradead.org, sagi@grimberg.me 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, Mar 05, 2020 at 01:50:58AM -0800, Dongli Zhang wrote: > Hi Keith, > > On 3/4/20 10:12 AM, Keith Busch wrote: > > Completion handling had been done in two steps: find all new completions > > under a lock, then handle those completions outside the lock. This was > > done to make the locked section as short as possible so that other > > threads using the same lock wait less time. > > > > The driver no longer shares locks during completion, and is in fact > > lockless for interrupt driven queues, so the optimization no longer > > About "no longer shares locks", would you mind share is it a specific nvme > driver commit, or the transition from sq to mq? They're all nvme specific commits. For the record, nvme never transitioned from 'sq' to 'mq'. We were bio-based before 'mq' existed. Commit splitting locks: 1ab0cd6966fc4a7e9dfbd7c6eda917ae9c977f42 Commit removing cq lock: 3a7afd8ee42a68d4f24ab9c947a4ef82d4d52375 _______________________________________________ linux-nvme mailing list linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme