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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACBC5C61DA4 for ; Mon, 13 Mar 2023 19:09:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229791AbjCMTJr (ORCPT ); Mon, 13 Mar 2023 15:09:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229723AbjCMTJq (ORCPT ); Mon, 13 Mar 2023 15:09:46 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D557102 for ; Mon, 13 Mar 2023 12:09:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C69F161461 for ; Mon, 13 Mar 2023 19:09:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5846C433EF; Mon, 13 Mar 2023 19:09:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678734584; bh=3khtob64uBXvckIf4dufyQjeuB+SGmmGMMKn0zv9hhY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=uH6GEvPumFTnxFZizlJ1VlzwnWfnSZPgtqhf35ZP0Tmb0BCvoOs/cKXr2VO9mIE3D p1dwU+kkFZgzuMhaExLDfk6yHbooURx1kCKnWZD2Hili63YTHLLvUrJ5F6UmiyHEpA vK6uw4FjeMdpNpJMelaZfXuLh4RS6+6XU5yqC/2g/uSZDkgrxxH7SGWhaRLI/FHPNN QCDPDKqJX+87aZTQCsEAgc6JzVvuDcC32ucKwRp2+pdySuf9/uZ/U6jzvWpaXtp+Sy IFT7xTSUyjlyFUwqPq2d8qfqbANS+xR4ZsFwSvXvNbxDIzvWrkltQMwYySRyoD1POn 3fynKncB/FPkg== Date: Mon, 13 Mar 2023 12:09:42 -0700 From: Jakub Kicinski To: Gal Pressman Cc: Shay Agroskin , David Miller , netdev@vger.kernel.org, "Woodhouse, David" , "Machulsky, Zorik" , "Matushevsky, Alexander" , Saeed Bshara , "Wilson, Matt" , "Liguori, Anthony" , "Bshara, Nafea" , "Belgazal, Netanel" , "Saidi, Ali" , "Herrenschmidt, Benjamin" , "Kiyanovski, Arthur" , "Dagan, Noam" , "Arinzon, David" , "Itzko, Shahar" , "Abboud, Osama" Subject: Re: [PATCH v4 net-next 1/5] ethtool: Add support for configuring tx_push_buf_len Message-ID: <20230313120942.75599b8e@kernel.org> In-Reply-To: References: <20230309131319.2531008-1-shayagr@amazon.com> <20230309131319.2531008-2-shayagr@amazon.com> <316ee596-e184-8613-d136-cd2cb13a589f@nvidia.com> <20230309225326.2976d514@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, 12 Mar 2023 14:41:39 +0200 Gal Pressman wrote: > On 10/03/2023 8:53, Jakub Kicinski wrote: > > On Thu, 9 Mar 2023 19:15:43 +0200 Gal Pressman wrote: > >> I know Jakub prefers the new parameter, but the description of this > >> still sounds extremely similar to TX copybreak to me.. > >> TX copybreak was traditionally used to copy packets to preallocated DMA > >> buffers, but this could be implemented as copying the packet to the > >> (preallocated) WQE's inline part. That usually means DMA memory, but > >> could also be device memory in this ENA LLQ case. > >> > >> Are we drawing a line that TX copybreak is the threshold for DMA memory > >> and tx_push_buf_len is the threshold for device memory? > > > > Pretty much, yes. Not an amazing distinction but since TX copybreak can > > already mean two different things (inline or DMA buf) I'd err on > > the side of not overloading it with another one. > > Can we document that please? Shay, could you add a paragraph in the docs regarding copybreak in v5?