From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.ebshome.net (gate.ebshome.net [208.106.21.240]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (Client CN "gate.ebshome.net", Issuer "gate.ebshome.net" (not verified)) by ozlabs.org (Postfix) with ESMTP id 670AEDDE1D for ; Wed, 18 Jul 2007 18:41:09 +1000 (EST) Date: Wed, 18 Jul 2007 01:34:25 -0700 From: Eugene Surovegin To: Andrew Morton Subject: Re: [Bugme-new] [Bug 8778] New: Ocotea board: kernel reports access of bad area during boot with DEBUG_SLAB=y Message-ID: <20070718083425.GA29722@gate.ebshome.net> References: <20070718005253.942f0464.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20070718005253.942f0464.akpm@linux-foundation.org> Cc: bart.vanassche@gmail.com, netdev@vger.kernel.org, "bugme-daemon@kernel-bugs.osdl.org" , linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Jul 18, 2007 at 12:52:53AM -0700, Andrew Morton wrote: > On Wed, 18 Jul 2007 00:07:50 -0700 (PDT) bugme-daemon@bugzilla.kernel.org wrote: > > > http://bugzilla.kernel.org/show_bug.cgi?id=8778 > > > > Summary: Ocotea board: kernel reports access of bad area during > > boot with DEBUG_SLAB=y Slab debugging is probably the culprit here. I had similar problem couple of years ago, not sure something has changed since then, haven't checked. When slab debugging was enabled it made memory allocations non L1 cache line aligned. This is very bad for DMA on non-coherent cache arches (PPC440 is one of those archs). I have a hack for EMAC which tries to "workaround" this problem: http://kernel.ebshome.net/emac_slab_debug.diff which might help. -- Eugene