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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 4582DC433E3 for ; Wed, 19 Aug 2020 10:49:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 269C72076E for ; Wed, 19 Aug 2020 10:49:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728033AbgHSKtZ (ORCPT ); Wed, 19 Aug 2020 06:49:25 -0400 Received: from verein.lst.de ([213.95.11.211]:37194 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727019AbgHSKtT (ORCPT ); Wed, 19 Aug 2020 06:49:19 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 2F14E68BEB; Wed, 19 Aug 2020 12:49:16 +0200 (CEST) Date: Wed, 19 Aug 2020 12:49:15 +0200 From: Christoph Hellwig To: Javier Gonzalez Cc: Christoph Hellwig , Kanchan Joshi , kbusch@kernel.org, Damien.LeMoal@wdc.com, axboe@kernel.dk, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, johannes.thumshirn@wdc.com, Nitesh Shetty , SelvaKumar S Subject: Re: [PATCH 2/2] nvme: add emulation for zone-append Message-ID: <20200819104915.GA3153@lst.de> References: <20200818052936.10995-1-joshi.k@samsung.com> <20200818052936.10995-3-joshi.k@samsung.com> <20200818071249.GB2544@lst.de> <20200818095033.h6ybdwiq3ljagl5a@mpHalley.local> <20200818155004.GA26688@lst.de> <20200818180428.obipue6adpqqpwjj@MacBook-Pro.localdomain> <20200819074035.GA21991@lst.de> <20200819083353.rwblagiesocfcq7i@mpHalley.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200819083353.rwblagiesocfcq7i@mpHalley.local> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 19, 2020 at 10:33:53AM +0200, Javier Gonzalez wrote: > I would ask you to reconsider this position. I have a hard time > understanding how zone append emulation is a good idea in SCSI and not > in NVMe, when there is no performance penalty. Per the numbers on btrfs and zonefs numbers zone append emulation is faster than using serialized writes, but also way slower than native zone append. Zone append emulation for SCSI is the way to bring support for pre-existing standards into the brave new world. Not requiring Zone Append in a standard designed around it because of bowing down to last minute political interventions in the standards committee is shooting ourselves in the foot. 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=-5.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 7BA71C433E1 for ; Wed, 19 Aug 2020 10:49:28 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 47073207DE for ; Wed, 19 Aug 2020 10:49:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Dxu/sUvU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 47073207DE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de 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=merlin.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=xQkhIfcFbfQu1qgp5QRTllGHrUNRDrNq9Q0dDmRvRxE=; b=Dxu/sUvUh+60FFUja2NATpFwA jBbQBH4tD8F9TiL8Uv4+BlevEzka/o3ijatOAlJMQzbQ53kX1kGDB95cStmextNL826nKJc7W2Ezc WFAopHcxFc3s/RnbpGKHn/TgP+F9FrpqfAAbYKcrBL3FveP340BiZkhc5ItFKE/eCPuKxKedMyxIk GUVfrh7O2PtHAoRrG8Nx85gePSy8Zgo/KxHGJKgziPhfsKp5HMGzXSPnqDZnIzeiZKUiZlQ4feqW0 xVKcSUvNiN1Ht54It4L4iQetsntLEagywb1kdUkROKMQ8sbs+GHSeJ2RecNn83ZxS0pg9hWsSygIL oBkmv3ZaQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8Lem-0003Tf-Ct; Wed, 19 Aug 2020 10:49:24 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8Leh-0003RL-1E for linux-nvme@lists.infradead.org; Wed, 19 Aug 2020 10:49:20 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 2F14E68BEB; Wed, 19 Aug 2020 12:49:16 +0200 (CEST) Date: Wed, 19 Aug 2020 12:49:15 +0200 From: Christoph Hellwig To: Javier Gonzalez Subject: Re: [PATCH 2/2] nvme: add emulation for zone-append Message-ID: <20200819104915.GA3153@lst.de> References: <20200818052936.10995-1-joshi.k@samsung.com> <20200818052936.10995-3-joshi.k@samsung.com> <20200818071249.GB2544@lst.de> <20200818095033.h6ybdwiq3ljagl5a@mpHalley.local> <20200818155004.GA26688@lst.de> <20200818180428.obipue6adpqqpwjj@MacBook-Pro.localdomain> <20200819074035.GA21991@lst.de> <20200819083353.rwblagiesocfcq7i@mpHalley.local> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200819083353.rwblagiesocfcq7i@mpHalley.local> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200819_064919_297123_49B16CB7 X-CRM114-Status: GOOD ( 10.77 ) 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: axboe@kernel.dk, Damien.LeMoal@wdc.com, SelvaKumar S , sagi@grimberg.me, Kanchan Joshi , johannes.thumshirn@wdc.com, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, Nitesh Shetty , kbusch@kernel.org, Christoph Hellwig 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 Wed, Aug 19, 2020 at 10:33:53AM +0200, Javier Gonzalez wrote: > I would ask you to reconsider this position. I have a hard time > understanding how zone append emulation is a good idea in SCSI and not > in NVMe, when there is no performance penalty. Per the numbers on btrfs and zonefs numbers zone append emulation is faster than using serialized writes, but also way slower than native zone append. Zone append emulation for SCSI is the way to bring support for pre-existing standards into the brave new world. Not requiring Zone Append in a standard designed around it because of bowing down to last minute political interventions in the standards committee is shooting ourselves in the foot. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme