From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Jarosch Subject: [PATCH] vmxnet3: Fix inconsistent LRO state after initialization Date: Mon, 16 May 2011 18:28:15 +0200 Message-ID: <201105161828.15237.thomas.jarosch@intra2net.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: Shreyas Bhatewara To: netdev@vger.kernel.org Return-path: Received: from rs04.intra2net.com ([85.214.66.2]:49714 "EHLO rs04.intra2net.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752311Ab1EPRDm (ORCPT ); Mon, 16 May 2011 13:03:42 -0400 Sender: netdev-owner@vger.kernel.org List-ID: During initialization of vmxnet3, the state of LRO gets out of sync with netdev->features. This leads to very poor TCP performance in a IP forwarding setup and is hitting many VMware users. Simplified call sequence: 1. vmxnet3_declare_features() initializes "adapter->lro" to true. 2. The kernel automatically disables LRO if IP forwarding is enabled, so vmxnet3_set_flags() gets called. This also updates netdev->features. 3. Now vmxnet3_setup_driver_shared() is called. "adapter->lro" is still set to true and LRO gets enabled again, even though netdev->features shows it's disabled. Fix it by updating "adapter->lro", too. The private vmxnet3 adapter flags are scheduled for removal in net-next, see commit a0d2730c9571aeba793cb5d3009094ee1d8fda35 "net: vmxnet3: convert to hw_features". Patch applies to 2.6.37 / 2.6.38 and 2.6.39-rc6. Please CC: comments. Signed-off-by: Thomas Jarosch diff -u -r -p linux-2.6.37.i686/drivers/net/vmxnet3/vmxnet3_ethtool.c linux-2.6.37.lro/drivers/net/vmxnet3/vmxnet3_ethtool.c --- linux-2.6.37.i686/drivers/net/vmxnet3/vmxnet3_ethtool.c 2011-05-16 17:43:26.652081801 +0200 +++ linux-2.6.37.lro/drivers/net/vmxnet3/vmxnet3_ethtool.c 2011-05-16 17:47:52.784081802 +0200 @@ -287,6 +287,9 @@ vmxnet3_set_flags(struct net_device *net /* toggle the LRO feature*/ netdev->features ^= NETIF_F_LRO; + /* Update private LRO flag */ + adapter->lro = lro_requested; + /* update harware LRO capability accordingly */ if (lro_requested) adapter->shared->devRead.misc.uptFeatures |=