Message ID | 201105161828.15237.thomas.jarosch@intra2net.com |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
On Mon, 16 May 2011 18:28:15 +0200 Thomas Jarosch <thomas.jarosch@intra2net.com> wrote: > 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 <thomas.jarosch@intra2net.com> > > 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 |= Thanks for finding this. Vyatta ended up changing the default of adapter->lro to workaround just this problem Acked-by: Stephen Hemminger <shemminger@vyatta.com>
From: Stephen Hemminger <shemminger@vyatta.com> Date: Mon, 16 May 2011 10:14:44 -0700 > On Mon, 16 May 2011 18:28:15 +0200 > Thomas Jarosch <thomas.jarosch@intra2net.com> wrote: > >> During initialization of vmxnet3, the state of LRO >> gets out of sync with netdev->features. ... >> Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com> > > Thanks for finding this. Vyatta ended up changing the default of adapter->lro > to workaround just this problem > > Acked-by: Stephen Hemminger <shemminger@vyatta.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 |=
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 <thomas.jarosch@intra2net.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html