From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932263AbXCRUYI (ORCPT ); Sun, 18 Mar 2007 16:24:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933092AbXCRUYI (ORCPT ); Sun, 18 Mar 2007 16:24:08 -0400 Received: from ug-out-1314.google.com ([66.249.92.175]:15546 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932223AbXCRUYE (ORCPT ); Sun, 18 Mar 2007 16:24:04 -0400 Date: Sun, 18 Mar 2007 22:24:44 +0200 From: "Michael S. Tsirkin" To: Alexey Kuznetsov Cc: "Michael S. Tsirkin" , Linux Kernel Mailing List , netdev@vger.kernel.org, general@lists.openfabrics.org, Roland Dreier Subject: Re: dst_ifdown breaks infiniband? Message-ID: <20070318202444.GC11078@mellanox.co.il> Reply-To: "Michael S. Tsirkin" References: <20070318155532.GG7958@mellanox.co.il> <20070318191238.GA20518@ms2.inr.ac.ru> <20070318194638.GA11078@mellanox.co.il> <20070318195558.GA27004@ms2.inr.ac.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070318195558.GA27004@ms2.inr.ac.ru> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Quoting Alexey Kuznetsov : > Subject: Re: dst_ifdown breaks infiniband? > > Hello! > > > Hmm. Something I don't understand: does the code > > in question not run on *each* device unregister? > > It does. > > > > Why do I only see this under stress? > > You should have some referenced destination entries to trigger bad path. > This should happen not only under stress. > > F.e. just try to ssh to something via this device. And unregister it. > Seems, the crash is inevitable. If you do not see crash, I will be puzzled. I did this. What happens is: neigh_setup is called dst_ifdown changes the neigh->dev to loopback device But the funny thing is that this neighbour can thinkably hang around indefinitely now, and if it does destructor won't be called and there won't be a crash. To trigger a crash, I did simply ifconfig lo down; ifconfig lo 127.0.0.1 and sure enough it crashes in drivers/infiniband/ulp/ipoib/ipoib_main.c. -- MST