From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753881AbYE3STU (ORCPT ); Fri, 30 May 2008 14:19:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752601AbYE3STF (ORCPT ); Fri, 30 May 2008 14:19:05 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:47716 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752403AbYE3STE (ORCPT ); Fri, 30 May 2008 14:19:04 -0400 Date: Fri, 30 May 2008 20:18:39 +0200 From: Ingo Molnar To: Ilpo J?rvinen Cc: LKML , Netdev , "David S. Miller" , "Rafael J. Wysocki" , Andrew Morton Subject: Re: [bug] stuck localhost TCP connections, v2.6.26-rc3+ Message-ID: <20080530181839.GA31915@elte.hu> References: <20080526115628.GA31316@elte.hu> <20080529084524.GA24892@elte.hu> <20080529112257.GA18130@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080529112257.GA18130@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > after about 50 bootups i got a hung test again: > > titan:~/tip> netstat -nt > Active Internet connections (w/o servers) > Proto Recv-Q Send-Q Local Address Foreign Address > State > tcp 0 0 10.0.1.14:22 10.0.1.16:58062 ESTABLISHED > tcp 0 0 10.0.1.14:22 10.0.1.16:60109 ESTABLISHED > tcp 0 86368 10.0.1.14:43914 10.0.1.16:3632 ESTABLISHED > > and this time with CUBIC_TCP disabled - so that was a red herring. ah, in retrospect i realized that this test had one flaw: some of the systems i the build cluster already ran a newer kernel and hence were targets for this bug. so i turned off CONFIG_TCP_CONG_CUBIC on all the testboxes and rebooted the cluster boxes into 2.6.25, and the hung sockets are now gone. (about 150 successful iterations) i did another change as well: i removed the localhost distcc component. I'll reinstate that now to make sure it's really related to TCP_CONG_CUBIC and not to localhost networking. Ingo