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 D469EC25B76 for ; Sat, 1 Jun 2024 05:47:25 +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:In-Reply-To:Content-Type: MIME-Version:References: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:List-Owner; bh=FDfev2XRL1yXC5cfA4G95FQrsHO1upVV9pZfbw8Ys+Q=; b=LoJZ2XDrbxfhwtOblNKrBrdWui +GLrI/8ULDsQ7kSm1RmjxaJSZI71JpfXcZS1SpPSwMl4zesJTWKUitNDCJ+GAUlTEYPG7zds4f2Tx U1oJHp0xwM85UE4xYuz0s6x1Twu2wZ++vhQ4IsbcG4FCUgIkkwgxQW1w/0c430Dp1ssgYCmd98036 GVWl0+hRjUJhNyMaPLP/ugnp6UU1ZSo6zk+VI6WGjrls76UAnCtVdsxaxmrG8DV8hMNtJG6EHtbBR Q3FMxvfPcXP3MvYATpQxWK4zhg+bnSeLRoUIh8lnUmtYnw5Ux3Vh1rXwVSHBaMQfQNtfUOQ6kpSNn F3BCe4hA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sDHaJ-0000000C1SC-2qKm; Sat, 01 Jun 2024 05:47:19 +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 1sDHaF-0000000C1Qq-29wO for linux-nvme@lists.infradead.org; Sat, 01 Jun 2024 05:47:17 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 3EE1068D17; Sat, 1 Jun 2024 07:47:02 +0200 (CEST) Date: Sat, 1 Jun 2024 07:47:01 +0200 From: Christoph Hellwig To: Nitesh Shetty Cc: Jens Axboe , Jonathan Corbet , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Keith Busch , Christoph Hellwig , 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: <20240601054701.GA5613@lst.de> References: <20240520102033.9361-1-nj.shetty@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240520102033.9361-1-nj.shetty@samsung.com> 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-20240531_224715_722822_135E238A X-CRM114-Status: GOOD ( 15.65 ) 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, May 20, 2024 at 03:50:13PM +0530, Nitesh Shetty wrote: > So copy offload works only for request based storage drivers. I don't think that is actually true. It just requires a fair amount of code in a bio based driver to match the bios up. I'm missing any kind of information on what this patch set as-is actually helps with. What operations are sped up, for what operations does it reduce resource usage? Part of that might be that the included use case of offloading copy_file_range doesn't seem particularly useful - on any advance file system that would be done using reflinks anyway. Have you considered hooking into dm-kcopyd which would be an instant win instead? Or into garbage collection in zoned or other log structured file systems? Those would probably really like multiple source bios, though.