From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: [PATCH v2 net] macvlan: Add support for 'always_on' offload features Date: Mon, 03 Mar 2014 15:49:40 -0800 Message-ID: <53151514.4080906@candelatech.com> References: <1393878833-17667-1-git-send-email-vyasevic@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Florian Westphal , Christian Borntraeger , Jason Wang , "Michael S. Tsirkin" To: Vlad Yasevich Return-path: Received: from mail.candelatech.com ([208.74.158.172]:53342 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755182AbaCCXtx (ORCPT ); Mon, 3 Mar 2014 18:49:53 -0500 In-Reply-To: <1393878833-17667-1-git-send-email-vyasevic@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On 03/03/2014 12:33 PM, Vlad Yasevich wrote: > Macvlan currently inherits all of its features from the lower > device. When lower device disables offload support, this causes > macvlan to disable offload support as well. This causes > performance regression when using macvlan/macvtap in bridge > mode. > > It can be easily demonstrated by creating 2 namespaces using > macvlan in bridge mode and running netperf between them: > > MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.0.0.1 () port 0 AF_INET > Recv Send Send > Socket Socket Message Elapsed > Size Size Size Time Throughput > bytes bytes bytes secs. 10^6bits/sec > > 87380 16384 16384 20.00 1204.61 > > To restore the performance, we add software offload features > to the list of "always_on" features for macvlan. This way > when a namespace or a guest using macvtap initially sends a > packet, this packet will not be segmented at macvlan level. > It will only be segmented when macvlan sends the packet > to the lower device. If users specifically disable the offload features on the macvlan using ethtool, will they be turned off? If not, then I think that logic should be kept somehow? Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com