From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f54.google.com (mail-pa0-f54.google.com [209.85.220.54]) by dpdk.org (Postfix) with ESMTP id 8D870532D for ; Sat, 10 May 2014 02:39:01 +0200 (CEST) Received: by mail-pa0-f54.google.com with SMTP id bj1so3728024pad.41 for ; Fri, 09 May 2014 17:39:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-type:content-transfer-encoding; bh=Q1uMBj9cvo67KSqMmQQQvM9u/NVrHMgPXL11XccaSVU=; b=Qiw8c1Vw5pwqtOxphjHKopPcYmXpx44CusJQrYHiAwhTHzXkuuG0k/uz6Ku42eGMaz eBT+KVqZufhRHuAB3JvWNj6i27d1HIq4zy3a4SvRh6pQUM4IRVgemXZk7C7GXAP+GqRy jrPL8rotmX0Hr8kc28oFTNkgAvLMGvToQCaIFELMCN+Xb6u1q0xR40NEthVqvCh0/Igq SciIfc8f+FHim5ui7Pbu8sRtn9WE4gl8t/fI2rpww8GcOb/57ZOeQDtrnYoaQ08WG3Sd 9CTpQrqUxYVtcvxkfSoPzncL1cWmhvG5vKFC1FHSUwSsr5zbcv+O5s8B66kb+I857ri3 QloA== X-Gm-Message-State: ALoCoQnRYHVBXxekhyJCYu4mD000IkgQpB6kQa7iEeIkmdjwdJVpCmQXrcje2d8ZE9EN3ApP4R6O X-Received: by 10.66.240.130 with SMTP id wa2mr26283319pac.73.1399682347513; Fri, 09 May 2014 17:39:07 -0700 (PDT) Received: from nehalam.linuxnetplumber.net (static-50-53-83-51.bvtn.or.frontiernet.net. [50.53.83.51]) by mx.google.com with ESMTPSA id no9sm9702096pbc.83.2014.05.09.17.39.06 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 09 May 2014 17:39:07 -0700 (PDT) Date: Fri, 9 May 2014 17:39:03 -0700 From: Stephen Hemminger To: Olivier MATZ Message-ID: <20140509173903.7c5464af@nehalam.linuxnetplumber.net> In-Reply-To: <536D4D79.4080609@6wind.com> References: <1399647038-15095-1-git-send-email-olivier.matz@6wind.com> <20140509100431.7af69959@nehalam.linuxnetplumber.net> <536D4D79.4080609@6wind.com> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH RFC 00/11] ixgbe/mbuf: add TSO support X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 10 May 2014 00:39:02 -0000 On Fri, 09 May 2014 23:49:45 +0200 Olivier MATZ wrote: > Hi Stephen, > > On 05/09/2014 07:04 PM, Stephen Hemminger wrote: > > I would also like to propose changing the checksum offload flags. > > Many devices can indicate good checksum in some cases but can't test > > for many other types of packets. By changing the flags to be: > > PKT_RX_L4_CKSUM_GOOD and PKT_RX_IP_CKSUM_GOOD > > > > It is then possible to support devices where some cases (IPv4 + TCP) > > are supported but others are not. > > I agree. That's also what I'm talking about in the commit log of > the patch 08/11. > > If there is not much rework for all the patches, I think it's feasible > to include this kind of modification in the v2 of this series. > > Regards, > Olivier > There are three checksum states: 1. Known good 2. Known bad 3. Can't tell Current choice of flags makes handling #3 impossible. If you change it to CKSUM_GOOD then 1 => GOOD, 2 => not GOOD, 3 => not GOOD. And for case #3 the software can validate it. For most cases IP checksum offload is meaning less anyway because the IP header fits in a single cache line, and the cost to checksum is minimal.