From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denys Fedoryshchenko Subject: Re: BUG? locking issue(networking?) with latest git Date: Thu, 4 Sep 2008 12:46:11 +0300 Message-ID: <200809041246.11255.denys@visp.net.lb> References: <20080904072155.GA4691@ff.dom.local> <200809041203.07460.denys@visp.net.lb> <20080904093854.GA5407@ff.dom.local> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Jarek Poplawski Return-path: Received: from relay2.globalproof.net ([194.146.153.25]:45572 "EHLO relay2.globalproof.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752607AbYIDJrb (ORCPT ); Thu, 4 Sep 2008 05:47:31 -0400 In-Reply-To: <20080904093854.GA5407@ff.dom.local> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On Thursday 04 September 2008, Jarek Poplawski wrote: > On Thu, Sep 04, 2008 at 12:03:07PM +0300, Denys Fedoryshchenko wrote: > > On Thursday 04 September 2008, Jarek Poplawski wrote: > > > On 03-09-2008 13:22, Denys Fedoryshchenko wrote: > > > > I am getting strange lockup, all operations (tc, ifconfig,pppd) after > > > > few days running pppoe-server. > > > > > > > > Programgs getting blocked very strange way, i am not able to kill > > > > them even. Softlockup detection enabled, lock dependencies (except > > > > lock dependency engine debugging), RT mutexes and deadlock detection > > > > enabled too. > > > > > > > > I notice this bug few weeks ago, even before latest patches, and > > > > seems it still remains. > > > > > > Do you mean this didn't happen with some 2.6.27-rc's? (There was quite > > > substantial change in ppp_generic with lock_kernel() in 2.6.27-rc1.) > > > > I was not able to run early rc's on my pppoe's. Do you suggest to try > > reverse those changes? > > No, I don't think reverting them would be easy enough (except moving > back to 2.6.26). I simply wonder if you think there were some > 2.6.27-rc's tried by you, which didn't lockup like this. There is sadly my shapers, which crashing on early rc's. > > > > Alas it shows only some tasks waiting for locks. Maybe it's enough for > > > someone with better ppp knowledge, but unless there is such a response > > > I guess you should better try with PROVE_LOCKING turned on yet. > > > > It is already turned on. > > So I misread this "except lock dependency engine debugging" part. OK, > I'll try to think about it, but any additional logs should be helpful. > BTW, I wonder if it's possible to test this without SMP? Done, booted with nosmp flag. Till crash i need to wait 1-3 days. I tried to check for any additional logs, but there is nothing seems. Once i got softlockup for pppd, and server restarted. Other times it is just getting stuck on any network operations (ifconfig, pppd crashing in the middle, tc). I am not able to attach to processes by strace/gdb, so it is difficult to tell even on which point it does crash. > > Jarek P.