Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756761AbZJSPcH (ORCPT ); Mon, 19 Oct 2009 11:32:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756694AbZJSPcG (ORCPT ); Mon, 19 Oct 2009 11:32:06 -0400 Received: from mail-px0-f179.google.com ([209.85.216.179]:53729 "EHLO mail-px0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756686AbZJSPcE (ORCPT ); Mon, 19 Oct 2009 11:32:04 -0400 Message-ID: <4ADC8677.7000607@anirban.org> Date: Mon, 19 Oct 2009 08:32:07 -0700 From: Anirban Sinha User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.4pre) Gecko/20090915 Thunderbird/3.0b4 MIME-Version: 1.0 To: Oleg Nesterov CC: linux-kernel@vger.kernel.org, David Miller , netdev@vger.kernel.org, Anirban Sinha Subject: Re: Kernel oops when clearing bgp neighbor info with TCP MD5SUM enabled References: <20091008.155429.02850661.davem@davemloft.net> <20091008.175703.83006470.davem@davemloft.net> <4ADA7EDC.5010402@anirban.org> <4ADB7856.7000803@anirban.org> <20091019121327.GA11423@redhat.com> In-Reply-To: <20091019121327.GA11423@redhat.com> X-Enigmail-Version: 0.97a Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1196 Lines: 36 Once upon a time, like on 09-10-19 5:13 AM, Oleg Nesterov wrote: > Hi Anirban, > > On 10/18, Anirban Sinha wrote: >> >> I have a question for you. The queue_work() routine which is called from >> schedule_work() does a put_cpu() which in turn does a enable_preempt(). Is >> this an attempt to trigger the scheduler? > > No. please note that queue_work() does get_cpu() + put_cpu() to protect > against cpu_down() in between. grrr! Ah yes, my eyes failed me (or it saw what I wanted it to see :)). You do have a get_cpu() and put_cpu() together in the same code path. I guess I will have to keep looking at inet_twdr_hangman(). >> Is is >> it illegal to schedule a work function from within a timer callback? > > Yes sure. hmm. may be in that case, that function needs to be re-written. > I'd suppose that this unbalance comes from inet_twdr_hangman() pathes. > > Could you verify this? I'll keep looking. Thanks for the help Oleg. Ani -- 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/