From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McManus Subject: Re: [fixed] [patch] Re: [bug] stuck localhost TCP connections, v2.6.26-rc3+ Date: Thu, 05 Jun 2008 19:29:31 -0400 Message-ID: <1212708571.19522.10.camel@tng> References: <20080603094057.GA29480@elte.hu> <20080603.150344.145518113.davem@davemloft.net> <20080605142244.GA19216@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Ingo Molnar , David Miller , peterz@infradead.org, LKML , Netdev , rjw@sisk.pl, Andrew Morton , johnpol@2ka.mipt.ru To: Ilpo =?ISO-8859-1?Q?J=E4rvinen?= Return-path: Received: from linode.ducksong.com ([64.22.125.164]:56784 "EHLO linode.ducksong.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753268AbYFEX32 (ORCPT ); Thu, 5 Jun 2008 19:29:28 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 2008-06-06 at 00:13 +0300, Ilpo J=E4rvinen wrote: >=20 > I'm out of new ideas what could be still wrong (I got confused and > lost=20 > track number of times while I tried to verify socket locking today an= d=20 > probably don't have more time for that now)... Unless somebody else=20 > (Patrick?) comes up with something quickly, Sorry, I don't see anything - it seems to boil down to the same code in the DA and non-DA case as far as I can tell, but after a while all the twisty passages seem to look alike. If Ingo confirms that the recv end was running the locking patch code, it would be interesting to just confirm the sysreq+t looks the same as before - it is possible the patch turned the race into a non-obvious deadlock. I'm sure your smaller revert will make the problem go away just as the larger one did, fwiw.=20 The other odd thing is that Ingo did a lot of experimentation and was only making this happen on localhost before (though I agree there is nothing inherent about that lock and localhost) - isn't it odd that the first trigger of it now is between two hosts? What do you make of that?