From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yurij M. Plotnikov" Subject: Re: PMTU discovery is broken on kernel 3.7.1 for UDP sockets Date: Mon, 21 Jan 2013 15:31:20 +0400 Message-ID: <50FD2708.6060906@oktetlabs.ru> References: <50D1BCC0.2000208@oktetlabs.ru> <1355924119.2676.6.camel@bwh-desktop.uk.solarflarecom.com> <50D1CECE.7090706@oktetlabs.ru> <1355945864.2676.21.camel@bwh-desktop.uk.solarflarecom.com> <20121220073445.GM18940@secunet.com> <50D2F4E5.4050904@oktetlabs.ru> <20121220123535.GN18940@secunet.com> <20121221102253.GO18940@secunet.com> <50F3C153.9030204@oktetlabs.ru> <20130118081145.GB24987@secunet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Ben Hutchings , netdev@vger.kernel.org, "Alexandra N. Kossovsky" To: Steffen Klassert Return-path: Received: from shelob.oktetlabs.ru ([195.131.132.186]:44115 "EHLO shelob.oktetlabs.ru" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752332Ab3AULbb (ORCPT ); Mon, 21 Jan 2013 06:31:31 -0500 In-Reply-To: <20130118081145.GB24987@secunet.com> Sender: netdev-owner@vger.kernel.org List-ID: On 01/18/13 12:11, Steffen Klassert wrote: > On Mon, Jan 14, 2013 at 12:26:59PM +0400, Yurij M. Plotnikov wrote: > >> Could you, please, tell me is there any news about this bug? >> >> > Ok, I tried to reconstruct your testcase and I can confirm this bug. > It happens only on the first pmtu event on a given route. It works > if I run this test again. Actually it works sometimes even on the > first pmtu event, so it took me quite a while to understand what's ging on. > > This is because standart routes (no pmtu or redirect events happened on > that route) are per cpu, so each cpu has it's own struct rtable. This means > that we do not invalidate the socket cached route if the NET_RX_SOFTIRQ > (which handles the pmtu event) is not served by the same cpu that the > sending socket uses. Exceptional routes (routes where a pmtu or redirect > event occured) are not per cpu, so there is no problem. > > I'll send three patches in reply to this mail. Applying patch one and two > should fix the bug you reported. If you use IPsec you need patch three too. > The patches are marked as RFC, I'll do proper patch submission if you can > confirm that they fix this bug. > Sorry for long delay. I've just checked patches 1+2 and they fix the bug for me. Yurij.