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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id B0159C25B76 for ; Wed, 5 Jun 2024 15:25:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=dW8kDUiWv1a4BNKFcv8PNWV+19665yDTaUr8bUH+HN0=; b=BvB5ijv2syw1I8wfGHKz1yJlu6 kzx4zkIw6MeKCtufsQY3mvLK+eov6t98uqVRYhV82uKuejwMDas2eyHy5Ww/MlML97r1BZiNFmc0+ 47jyAeHFl0hFgOINmRuUh3aXgBCrA7CjvygWdM3hYdbE3ztDBAIVBb0krN20YdCW7mmFKvIj4MdWp +Y1Y7+EsBC1J/9QobGArafHsgOkz9qMmsZFP29OFsom60GiwKnn02loRvCjDkDBYu6JsHnjt24MkI /GQF2Dp9eRYyk+63LdWmqZCj3peGhgx9NalmMPjWJAQcXOe5euaOmiNOJ8FvFijAqu9QLqvkqxrc/ 1AEPxAKQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sEsVR-00000006bcj-0R84; Wed, 05 Jun 2024 15:24:53 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sELqn-00000001BYk-2YDa for linux-nvme@lists.infradead.org; Tue, 04 Jun 2024 04:32:47 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id D3F6168D12; Tue, 4 Jun 2024 06:32:42 +0200 (CEST) Date: Tue, 4 Jun 2024 06:32:42 +0200 From: Christoph Hellwig To: Nitesh Shetty Cc: Christoph Hellwig , Jens Axboe , Jonathan Corbet , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Keith Busch , Sagi Grimberg , Chaitanya Kulkarni , Alexander Viro , Christian Brauner , Jan Kara , martin.petersen@oracle.com, bvanassche@acm.org, david@fromorbit.com, hare@suse.de, damien.lemoal@opensource.wdc.com, anuj20.g@samsung.com, joshi.k@samsung.com, nitheshshetty@gmail.com, gost.dev@samsung.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, dm-devel@lists.linux.dev, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v20 00/12] Implement copy offload support Message-ID: <20240604043242.GC28886@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.17 (2007-11-01) X-Bad-Reply: 'Re:' in Subject but no References or In-Reply-To headers X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240603_213245_888486_B1BE21E5 X-CRM114-Status: GOOD ( 14.97 ) X-Mailman-Approved-At: Wed, 05 Jun 2024 08:24:51 -0700 X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Mon, Jun 03, 2024 at 10:53:39AM +0000, Nitesh Shetty wrote: > The major benefit of this copy-offload/emulation framework is > observed in fabrics setup, for copy workloads across the network. > The host will send offload command over the network and actual copy > can be achieved using emulation on the target (hence patch 4). > This results in higher performance and lower network consumption, > as compared to read and write travelling across the network. > With this design of copy-offload/emulation we are able to see the > following improvements as compared to userspace read + write on a > NVMeOF TCP setup: What is the use case of this? What workloads does raw copies a lot of data inside a single block device?