Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932289AbVJQMmy (ORCPT ); Mon, 17 Oct 2005 08:42:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932298AbVJQMmy (ORCPT ); Mon, 17 Oct 2005 08:42:54 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:29654 "EHLO e3.ny.us.ibm.com") by vger.kernel.org with ESMTP id S932289AbVJQMmx (ORCPT ); Mon, 17 Oct 2005 08:42:53 -0400 Date: Mon, 17 Oct 2005 18:06:55 +0530 From: Dipankar Sarma To: Eric Dumazet Cc: Jean Delvare , torvalds@osdl.org, Serge Belyshev , LKML , Andrew Morton , Manfred Spraul Subject: Re: [RCU problem] was VFS: file-max limit 50044 reached Message-ID: <20051017123655.GD6257@in.ibm.com> Reply-To: dipankar@in.ibm.com References: <20051017084609.GA6257@in.ibm.com> <43536A6C.102@cosmosbay.com> <20051017103244.GB6257@in.ibm.com> <435394A1.7000109@cosmosbay.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <435394A1.7000109@cosmosbay.com> User-Agent: Mutt/1.5.10i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1295 Lines: 34 On Mon, Oct 17, 2005 at 02:10:09PM +0200, Eric Dumazet wrote: > Dipankar Sarma a ?crit : > >On Mon, Oct 17, 2005 at 11:10:04AM +0200, Eric Dumazet wrote: > > > >Agreed. It is not designed to work that way, so there must be > >a bug somewhere and I am trying to track it down. It could very well > >be that at maxbatch=10 we are just queueing at a rate far too high > >compared to processing. > > > > I can freeze my test machine with a program that 'only' use dentries, no > files. > > No message, no panic, but machine becomes totally unresponsive after few > seconds. > > Just greping for call_rcu in kernel sources gave me another call_rcu() use > from syscalls. And yes 2.6.13 has the same problem. Can you try it with rcupdate.maxbatch set to 10000 in boot command line ? FWIW, the open/close test problem goes away if I set maxbatch to 10000. I had introduced this limit some time ago to curtail the effect long running softirq handlers have on scheduling latencies, which now conflicts with OOM avoidance requirements. Thanks Dipankar - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/