From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 131C0A04AC; Mon, 31 Aug 2020 18:59:31 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 668631C0BD; Mon, 31 Aug 2020 18:59:29 +0200 (CEST) Received: from mail-pj1-f66.google.com (mail-pj1-f66.google.com [209.85.216.66]) by dpdk.org (Postfix) with ESMTP id B1DCC1C08C for ; Mon, 31 Aug 2020 18:59:27 +0200 (CEST) Received: by mail-pj1-f66.google.com with SMTP id o16so112053pjr.2 for ; Mon, 31 Aug 2020 09:59:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=c5q+niWIxGaYt2pGr+RCjy0udVcEWYADFY2aedihRtg=; b=tn2JokNEm60uvLxwctua6hIatIVA0aFHTi4Hy2vSDulY0E8Tsy1Bh3rYTespsxW6CX P0xYhgv7NetTARlflQ//xpVMyMblsl6O5i27D/Bf8XKoWjPmbCYaH7iKd+IJ+S9T2Ook VGIDY6jiS7pHDgjQsyIr3bqTcB89/vEB5Hoc58sOsMgjsrRvRLb9D/CgoSYzGFfhbAfy qd3wJW7UARbjav+jYvMsuv3gpsq4fMexzlIxabpCpbl5nmzvfouE0p9d63w/kJY2MeTo AMWeIBvCPeyZVztTjhPhkRPiVcYBxD09D1iBzxgk+34iiu06u2ZlR7n4nEtO72/KqQO0 YAlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=c5q+niWIxGaYt2pGr+RCjy0udVcEWYADFY2aedihRtg=; b=aMN+aRFIrzO67trJsG8+/8SXT9OWGfZ5wHhOfmb9bTc4GdSBXiaNg8mqeGgpfmJ/zh RSHwEIrRoMT++sRimMjgvqQ6srglAQm2+lwttQ/JX9G1X3hcOeS3FVW7w+7W+vDvPf10 CTI5tVNyY1pQfTH4hgpWCL11ptdTokLq2SJPOuKM6eW5+H6cfRcVO3fQbBDpiqr65tjm XfjT3FCTYjRfGoDtqka4AWzJd+k6BcfOABAYZgLt0cbFB642kt47JlaijC/FODTHOi47 SlMXztM/ZD7oM/mZcCfCo31Xf4ZpFY4uoK4x3XqTr5P5Tm42CYRBtSP1fI5wRqBfg1S4 ZQng== X-Gm-Message-State: AOAM531YHY+cYPkPeJeePq2ZPVpzEUcDX3c0vZ28+OHXQ4sZvFzLcwT2 M+taynWL0+jZz6CYOIZSOHqTTg== X-Google-Smtp-Source: ABdhPJzJ587DOLhTP0yUmwMVugaVer9nGV1qTz1q+4X9AmtRsZoVhVwz81ybYCfXFNkVSTR9RDv2kA== X-Received: by 2002:a17:90a:d90f:: with SMTP id c15mr265169pjv.85.1598893166727; Mon, 31 Aug 2020 09:59:26 -0700 (PDT) Received: from hermes.lan (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id np4sm136310pjb.4.2020.08.31.09.59.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Aug 2020 09:59:26 -0700 (PDT) Date: Mon, 31 Aug 2020 09:59:18 -0700 From: Stephen Hemminger To: Andrew Rybchenko Cc: Slava Ovsiienko , "dev@dpdk.org" , Matan Azrad , Raslan Darawsheh , Thomas Monjalon , "ferruh.yigit@intel.com" , "jerinjacobk@gmail.com" , "ajit.khaparde@broadcom.com" , "maxime.coquelin@redhat.com" , "olivier.matz@6wind.com" , "david.marchand@redhat.com" Message-ID: <20200831095918.6d357675@hermes.lan> In-Reply-To: References: <79886244-1390-6c99-287d-1d868bb4090a@solarflare.com> <20200830112658.0d5f532e@hermes.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH] doc: announce changes to ethdev rxconf structure X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Mon, 31 Aug 2020 09:35:18 +0300 Andrew Rybchenko wrote: > >>>>> multisegment packets. > >>>> > >>>> I hope it will be mentioned in the feature documentation in the future, but > >>>> I'm not 100% sure that it is required. See below. > >>> I suppose there is the hierarchy: > >>> - applications configures DEV_RX_OFFLOAD_SCATTER on the port and tells in this way: > >>> "Hey, driver, I'm ready to handle multi-segment packets". Readiness in general. > >>> - application configures BUFFER_SPLIT and tells PMD _HOW_ it wants to split, in particular way: > >>> "Hey, driver, please, drop ten bytes here, here and here, and the rest - over there" > >> > >> My idea is to keep SCATTER and BUFFER_SPLIT independent. > >> SCATTER is a possibility to make multi-segment packets getting > >> mbufs from main rxq mempool as many as required. > >> BUFFER_SPLIT is support of many mempools and splitting > >> received packets as specified. > > > > No. > > Once again, drivers should take anything from application and rely on using > > logic to choose best path. Modern CPU's have good branch predictors, and making > > the developer do that work is counter productive. > > Please, add a bit more details. I simply can see relationship. > So, right now for me it looks like just misunderstanding. > > Thanks, > Andrew. Ok, documenting the existing behaviour is good. I was just concerned that this was going to lead to more per-queue flags.