From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 96D84A00C4; Fri, 1 Jul 2022 11:48:44 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 41DBF4069D; Fri, 1 Jul 2022 11:48:44 +0200 (CEST) Received: from mail-wr1-f53.google.com (mail-wr1-f53.google.com [209.85.221.53]) by mails.dpdk.org (Postfix) with ESMTP id A9A6740150 for ; Fri, 1 Jul 2022 11:48:43 +0200 (CEST) Received: by mail-wr1-f53.google.com with SMTP id d17so2376657wrc.10 for ; Fri, 01 Jul 2022 02:48:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind.com; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=2F5WdfUf+nlle4fV4Q7CkOfHjwD+1fnnDofngFfMpQE=; b=C4uNZskvr4hSWwIBk2bz6hGUOAj7XAKjikA44Yej9BUqLCjGnYkpHh/uOMe3m7b5NA 8U9sDx3b5rpR/+MNoK1HeNc3qGfu3YpoDpmgudzG7leWskNX6vmO2/x3zhcdRApoOi8f jPvx6b+t2xKVh15+ss0v/IcSoGSp3HM5GSEA32kjprUAX2cL2tnpMtP0ZJB5geRREXdC zfRaMqDssNA6CRPxerU1JhxT7AbmDEQyzePSdnLXwzBr8a9VPhHsUlpov2T5ZmR5ITsz uVVdz2sNr/0oH3uLlVSCltYDG5bF5vBqm/OFH2u45LbJkzMp4jIIzzMQZGEZAhfCRpXv 01fg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=2F5WdfUf+nlle4fV4Q7CkOfHjwD+1fnnDofngFfMpQE=; b=CUwV37I+HX81BeOULToHAsDYi6SKRm17ZrjFLLNuVifkWywbfu85LSk+CFc7X+oLoM rMMYgIsB+EUQM4ABJEQO4JGJzWaPkqnccKrTQhjo1/tJ+602lJaUpFEMnTt59GegCpZn IOz7yDTVPyykerzvnZ1PrMQP0+Ho1mA80gVqpg5p1cFWYakbIyimMr+HVzshyMtKdvdm psA6mUqKACULoEjdvHpN5eoOMmhhDhGxWe5rBeV+1YGt8XNqFFtYH9jXGbC348sANluB Ew0Ci2iEWrL8dQUvX2H0MK8zRtk/Du+EH5lD54+QCp5AIqLgL7kSjCca2e8nC6Xfv3SV giyw== X-Gm-Message-State: AJIora+WEcnZrcRNnHA/siIgj+XeASXiipN19l28J8HC/vGAdOeJSHXR RvkYQwhxYoB+1eb6vROaSwDNyw== X-Google-Smtp-Source: AGRyM1tUIGJbhmTT4BIGr31t0D77yQQzjzC1ptFErpmDH5Olb8YPRYIcS01PePpxJG9IzT/OTVPXmg== X-Received: by 2002:adf:e252:0:b0:21b:827e:4c63 with SMTP id bl18-20020adfe252000000b0021b827e4c63mr12516035wrb.307.1656668923345; Fri, 01 Jul 2022 02:48:43 -0700 (PDT) Received: from 6wind.com ([2a01:e0a:5ac:6460:c065:401d:87eb:9b25]) by smtp.gmail.com with ESMTPSA id q12-20020a5d61cc000000b0021cf31e1f7csm14052861wrv.102.2022.07.01.02.48.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 Jul 2022 02:48:42 -0700 (PDT) Date: Fri, 1 Jul 2022 11:48:41 +0200 From: Olivier Matz To: Bruce Richardson Cc: Shijith Thotton , jerinj@marvell.com, thomas@monjalon.net, dev@dpdk.org Subject: Re: [PATCH] mbuf: add mbuf physical address field to dynamic field Message-ID: References: <57d2ab7fff672716d37ba4078e2e3bb2db126607.1656605763.git.sthotton@marvell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Hi, On Thu, Jun 30, 2022 at 05:55:21PM +0100, Bruce Richardson wrote: > On Thu, Jun 30, 2022 at 09:55:16PM +0530, Shijith Thotton wrote: > > If all devices are configured to run in IOVA mode as VA, physical > > address field of mbuf (buf_iova) won't be used. In such cases, buf_iova > > space is free to use as a dynamic field. So a new dynamic field member > > (dynfield2) is added in mbuf structure to make use of that space. > > > > A new mbuf flag RTE_MBUF_F_DYNFIELD2 is introduced to help identify the > > mbuf that can use dynfield2. > > > > Signed-off-by: Shijith Thotton > > --- > I disagree with this patch. The mbuf should always record the iova of the > buffer directly, rather than forcing the drivers to query the EAL mode. > This will likely also break all vector drivers right now, as they are > sensitive to the mbuf layout and the position of the IOVA address in the > buffer. I have the same opinion than Stephen and Bruce. This field is widely used in DPDK, I don't think it is a good idea to disable it if some conditions are met.