From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: tap/bridge: Dropping NETIF_F_GSO/NETIF_F_SG Date: Mon, 16 May 2011 12:48:21 +0300 Message-ID: <20110516094821.GA9427@redhat.com> References: <20110504181813.GA17547@redhat.com> <20110504223415.GA14819@gondor.apana.org.au> <20110504232854.GA11687@rere.qmqm.pl> <20110505084428.GB17647@redhat.com> <4DC26F33.8010700@cn.fujitsu.com> <20110505100506.GA20111@gondor.apana.org.au> <20110516073210.GB6610@redhat.com> <20110516080702.GA1857@gondor.apana.org.au> <20110516081841.GA8073@redhat.com> <20110516093822.GA2779@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Shan Wei , =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= , netdev@vger.kernel.org, Ben Hutchings To: Herbert Xu Return-path: Received: from mx1.redhat.com ([209.132.183.28]:39426 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753294Ab1EPJsV (ORCPT ); Mon, 16 May 2011 05:48:21 -0400 Content-Disposition: inline In-Reply-To: <20110516093822.GA2779@gondor.apana.org.au> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, May 16, 2011 at 07:38:22PM +1000, Herbert Xu wrote: > On Mon, May 16, 2011 at 11:18:41AM +0300, Michael S. Tsirkin wrote: > > > > There's no interface for userspace to enable it: userspace > > only has an ioctl to enable/disable checksum offloading. > > SG is an implementation detail. > > Yes there is: ethtool -K > > Cheers, Ok. You are right of course, I was confused. So it's just an info message: in the end if userspace DTRT features get enabled properly. Functionally, there is no regression. Both bridge and tun trigger the messages ATM. I note that dev.c takes pains to avoid these messages: Avoid warning from netdev_fix_features() for GSO without SG Should all drivers do this: clear _SG if they clear checksum? What about _GSO? If we start doing this, this spills info about flag dependencies out to drivers. -- MST