From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: Re: [RFC PATCH net-next] qfq: handle the case that front slot is empty Date: Tue, 23 Oct 2012 16:53:52 +0800 Message-ID: <1350982432.26308.8.camel@cr0> References: <1350965711-4390-1-git-send-email-amwang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Stephen Hemminger , Eric Dumazet , "David S. Miller" To: Paolo Valente Return-path: Received: from mx1.redhat.com ([209.132.183.28]:8760 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932503Ab2JWIyH (ORCPT ); Tue, 23 Oct 2012 04:54:07 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 2012-10-23 at 09:09 +0200, Paolo Valente wrote: > The crash you reported is one of the problems I tried to solve with my last fixes. > After those fixes I could not reproduce this crash (and other crashes) any more, but of course I am still missing something. I am using the latest net-next, so if your patches are in net-next, then the problem of course still exists. > > Il giorno 23/ott/2012, alle ore 06:15, Cong Wang ha scritto: > > > I am not sure if this patch fixes the real problem or just workarounds > > it. At least, after this patch I don't see the crash I reported any more. > > It is actually a workaround: if the condition that triggers your workaround holds true, then the group data structure is already inconstent, and qfq is likely not to schedule classes correctly. > I will try to reproduce the crash with the steps you suggest, and try to understand what is still wrong as soon as I can. > OK, I don't pretend I understand qfq. And I can help you to test patches. Thanks!