From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH] Disable TSO for non standard qdiscs Date: Thu, 31 Jan 2008 09:23:27 -0800 Message-ID: <20080131092327.75b9c369@extreme> References: <20080131124632.GA25299@basil.nowhere.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Andi Kleen Return-path: Received: from mail.vyatta.com ([216.93.170.194]:48055 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753732AbYAaRXc (ORCPT ); Thu, 31 Jan 2008 12:23:32 -0500 In-Reply-To: <20080131124632.GA25299@basil.nowhere.org> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 31 Jan 2008 13:46:32 +0100 Andi Kleen wrote: > > TSO interacts badly with many queueing disciplines because they rely on > reordering packets from different streams and the large TSO packets can > make this difficult. This patch disables TSO for sockets that send over > devices with non standard queueing disciplines. That's anything but noop > or pfifo_fast and pfifo right now. > > Longer term other queueing disciplines could be checked if they > are also ok with TSO. If yes they can set the TCQ_F_GSO_OK flag too. > > It is still enabled for the standard pfifo_fast because that will never > reorder packets with the same type-of-service. This means 99+% of all users > will still be able to use TSO just fine. > > The status is only set up at socket creation so a shifted route > will not reenable TSO on a existing socket. I don't think that's a > problem though. > > Signed-off-by: Andi Kleen > Fix the broken qdisc instead. -- Stephen Hemminger