From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mgw.gov.kz (mgw.gov.kz [89.218.88.242]) by dpdk.org (Postfix) with ESMTP id 0E60658EE for ; Thu, 4 Sep 2014 07:05:53 +0200 (CEST) Received: from mgw.gov.kz (mx.ctsat.kz [178.89.4.95]) by mgw.gov.kz with ESMTP id s845AVlN020067-s845AVlO020067; Thu, 4 Sep 2014 11:10:31 +0600 Received: from EXCASHUB2.rgp.local (192.168.40.53) by EdgeForefront.rgp.local (192.168.40.59) with Microsoft SMTP Server (TLS) id 14.2.247.3; Thu, 4 Sep 2014 11:09:26 +0600 Received: from [192.168.35.15] (192.168.35.15) by excashub2.rgp.local (192.168.40.48) with Microsoft SMTP Server (TLS) id 14.2.247.3; Thu, 4 Sep 2014 11:10:26 +0600 Message-ID: <5407F3E9.6080907@sts.kz> Date: Thu, 4 Sep 2014 11:08:57 +0600 From: Yerden Zhumabekov User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: "dev@dpdk.org" References: <1409759378-10113-1-git-send-email-bruce.richardson@intel.com> <1409759378-10113-12-git-send-email-bruce.richardson@intel.com> In-Reply-To: <1409759378-10113-12-git-send-email-bruce.richardson@intel.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset="windows-1251" Content-Transfer-Encoding: 8bit X-Originating-IP: [192.168.35.15] X-FEAS-SYSTEM-WL: e_zhumabekov@sts.kz Subject: Re: [dpdk-dev] [PATCH 11/13] mbuf: move l2_len and l3_len to second cache line 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: Thu, 04 Sep 2014 05:05:54 -0000 Hello Bruce, I'm a little bit concerned about performance issues that would arise if these fields would go to the 2nd cache line. For exampe, l2_len and l3_len fields are used by librte_ip_frag to find L3 and L4 headers position inside mbuf data. Thus, these values should be calculated by NIC offload, or by user on RX leg. Secondly, (I wouldn't say on behalf of everyone, but) we use these fields in our libraries as well for needs of classification. For instance, in case you try to support other ethertypes which are not supported by NIC offload (MPLS, IPX etc), but you still need to point out L3 and L3 headers. If my concerns are consistent, what would be possible suggestions? 03.09.2014 21:49, Bruce Richardson пишет: > The l2_len and l3_len fields are used for TX offloads and so should be > put on the second cache line, along with the other fields only used on > TX. > > Signed-off-by: Bruce Richardson -- Sincerely, Yerden Zhumabekov STS, ACI Astana, KZ