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 A9F92E71062 for ; Thu, 21 Sep 2023 12:33:28 +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-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=eynQlZvjE27JhyoDUSsmCVMjkh9tOc45JWjWr2Vd8i4=; b=4Kmt+rb5VvaaVA7EunuRPn2Btn cTv86N++iBmCz0gf5SsG8mFrMavETKxBmdtXlh1cXRXHLju+lEVr4TVXr2VmCjoxFcHlwvWoMd3HR JBk2NGL5sqZ8GUWgmAAU7GNqaLr5CxGvHiU9F/aKyLq+7DX+WXh6sGxFzZhVFWGPn5erRu5WL76aC FbR3wKU6Ag/5VMoomtNwS/Kd3eWUrPEa3+WGTk8JDJH7ySPWCG6h2FkC241f2rdfvUD9nW3mzkGe8 K1UosF90ipCaYsJ75FgSZ5jFPEHKGRa7kjGMbhJXNYeAtrJ6eso9BQBQOChvzn4g8TUX7BPZB2D55 JrrJxrMQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qjIry-0061rv-2g; Thu, 21 Sep 2023 12:33:22 +0000 Received: from sin.source.kernel.org ([145.40.73.55]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qjIrw-0061pA-07 for linux-nvme@lists.infradead.org; Thu, 21 Sep 2023 12:33:21 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id D4010CE220F; Thu, 21 Sep 2023 12:33:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45C28C32781; Thu, 21 Sep 2023 12:33:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695299592; bh=I2wdsC3bwatwPq1wviIFhcLzP9nRh4x476U8QpzzmYo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=NC8H/ohiAWX3OutaLR4Cya1zHBgBXqp7c2GIxnn8JAcfcpw7xwjEjAdQaNzq0/YBS FTUUhrz0vR+5jF2OmTX1zVZPdeyizSjanbALvylLLsr1qW5Ibw/JkdVBla0IMCaRwl tmr+1t9d8u5l3stCZt2xmSWtBn5coDerTofphOvUytFzG3T2qkJZTGTasnW8ydIw8G KsNMumgxh0LjKs8MFjhUYrBITMx88d3J0vLwsAAI/ilhVQEVOnxZq1aYlDj/v5jX6T 8XWNwoqKkdyMYiePha7rrNeU2+o2AkrH0FtDATXlenRLv1j0t3IJGKcXEBAXJbP1dO jRrhZkKj49SXg== Message-ID: Date: Thu, 21 Sep 2023 06:33:10 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH v15 01/20] net: Introduce direct data placement tcp offload To: Aurelien Aptel , linux-nvme@lists.infradead.org, netdev@vger.kernel.org, sagi@grimberg.me, hch@lst.de, kbusch@kernel.org, axboe@fb.com, chaitanyak@nvidia.com, davem@davemloft.net, kuba@kernel.org Cc: Boris Pismenny , aurelien.aptel@gmail.com, smalin@nvidia.com, malin1024@gmail.com, ogerlitz@nvidia.com, yorayz@nvidia.com, galshalom@nvidia.com, mgurtovoy@nvidia.com, edumazet@google.com, pabeni@redhat.com, imagedong@tencent.com References: <20230912095949.5474-1-aaptel@nvidia.com> <20230912095949.5474-2-aaptel@nvidia.com> <4ae938a0-6331-f5d6-baa5-62eb8b07e63f@kernel.org> <253y1h0j7j6.fsf@mtr-vdi-124.i-did-not-set--mail-host-address--so-tickle-me> Content-Language: en-US From: David Ahern In-Reply-To: <253y1h0j7j6.fsf@mtr-vdi-124.i-did-not-set--mail-host-address--so-tickle-me> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230921_053320_270091_00537A03 X-CRM114-Status: GOOD ( 11.77 ) 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 9/21/23 1:43 AM, Aurelien Aptel wrote: > David Ahern writes: >> Not consolidating frags into linear is a requirement for any Rx ZC >> solution (e.g., the gpu devmem RFC set and accompanying io_uring set for >> userspace memory). Meaning, the bit can be more generic and less tied to >> ulp_ddp. > > In our view the ULP Direct Data Placement has a very specific design and > avoiding skb coalescing is just one aspect of it. > It would be hard to make it generic for any type of zero copy design. We > can rename the bit to "ddp" or "zerocopy" if you prefer but it might end > up being more misleading. The number of single use case bits on sk_buff are piling up. In this case, skb->ulp_ddp is only used to avoid skb_condense, so name it accordingly. skb->no_condense for example.