From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: [PATCH net] ipv4: allow local fragmentation in ip_finish_output_gso() Date: Wed, 02 Nov 2016 18:17:32 +0100 Message-ID: <1478107052.1833947.775286313.0A06B9DC@webmail.messagingengine.com> References: <1478104158-9504-1-git-send-email-lrichard@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit To: Lance Richardson , netdev@vger.kernel.org, fw@strlen.de, jtluka@redhat.com Return-path: Received: from out2-smtp.messagingengine.com ([66.111.4.26]:51383 "EHLO out2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933374AbcKBRRd (ORCPT ); Wed, 2 Nov 2016 13:17:33 -0400 In-Reply-To: <1478104158-9504-1-git-send-email-lrichard@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Nov 2, 2016, at 17:29, Lance Richardson wrote: > Some configurations (e.g. geneve interface with default > MTU of 1500 over an ethernet interface with 1500 MTU) result > in the transmission of packets that exceed the configured MTU. > While this should be considered to be a "bad" configuration, > it is still allowed and should not result in the sending > of packets that exceed the configured MTU. > > Fix by dropping the assumption in ip_finish_output_gso() that > locally originated gso packets will never need fragmentation. > Basic testing using iperf (observing CPU usage and bandwidth) > have shown no measurable performance impact for traffic not > requiring fragmentation. > > Fixes: c7ba65d7b649 ("net: ip: push gso skb forwarding handling down the > stack") > Reported-by: Jan Tluka > Signed-off-by: Lance Richardson Acked-by: Hannes Frederic Sowa