From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anirban Chakraborty Subject: Re: [PATCH net-next] xen-netfront: convert to GRO API and advertise this feature Date: Sun, 22 Sep 2013 23:09:35 +0000 Message-ID: References: <1379779543-27122-1-git-send-email-wei.liu2@citrix.com> <1379861723.3431.10.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Cc: Wei Liu , "" , "" , Ian Campbell To: Eric Dumazet Return-path: Received: from co1ehsobe001.messaging.microsoft.com ([216.32.180.184]:52245 "EHLO co1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752340Ab3IVXJl convert rfc822-to-8bit (ORCPT ); Sun, 22 Sep 2013 19:09:41 -0400 In-Reply-To: <1379861723.3431.10.camel@edumazet-glaptop> Content-Language: en-US Content-ID: <5D5580385783D147BB6F04707B1B07C8@namprd05.prod.outlook.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sep 22, 2013, at 7:55 AM, Eric Dumazet wrote: > On Sat, 2013-09-21 at 17:05 +0100, Wei Liu wrote: >> Anirban was seeing netfront received MTU size packets, which downgraded >> throughput. The following patch makes netfront use GRO API which >> improves throughput for that case. > >> - netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO; >> + netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO | >> + NETIF_F_GRO; > > > This part is not needed. Shouldn't the flag be set? In dev_gro_receive() we do check if this flag is set or not: if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb)) goto normal; -Anirban