From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Bart Van Assche" Subject: Re: [Bugme-new] [Bug 8778] New: Ocotea board: kernel reports access of bad area during boot with DEBUG_SLAB=y Date: Wed, 18 Jul 2007 20:43:46 +0200 Message-ID: References: <20070718005253.942f0464.akpm@linux-foundation.org> <20070718083425.GA29722@gate.ebshome.net> <1184766070.3699.2.camel@zod.rchland.ibm.com> <20070718155940.GB29722@gate.ebshome.net> <20070718095537.d344dc0a.akpm@linux-foundation.org> <20070718170433.GC29722@gate.ebshome.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1603235888==" Return-path: In-Reply-To: <20070718170433.GC29722@gate.ebshome.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Mime-version: 1.0 Sender: linuxppc-embedded-bounces+glppe-linuxppc-embedded-2=m.gmane.org@ozlabs.org Errors-To: linuxppc-embedded-bounces+glppe-linuxppc-embedded-2=m.gmane.org@ozlabs.org To: Eugene Surovegin Cc: netdev@vger.kernel.org, linux-mm@kvack.org, "bugme-daemon@kernel-bugs.osdl.org" , linuxppc-embedded@ozlabs.org, Andrew Morton , Christoph Lameter List-Id: linux-mm.kvack.org --===============1603235888== Content-Type: multipart/alternative; boundary="----=_Part_101522_6960589.1184784226940" ------=_Part_101522_6960589.1184784226940 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline On 7/18/07, Eugene Surovegin wrote: > > > It's kmalloc, at least this is how I think skbs are allocated. > > Andrew, I don't have access to PPC hw right now (doing MIPS > development these days), so I cannot quickly check that my theory is > still correct for the latest kernel. I'd wait for the reporter to try > my hack and then we can decide what to do. IIRC there was some > provision in slab allocator to enforce alignment, when I was debugging > this problem more then a year ago, that option didn't work. > > BTW, I think slob allocator had the same issue with alignment as slab > with enabled debugging (at least at the time I looked at it). Hello Eugene, In case you didn't notice yet, I have added the following comment to the kernel bugzilla item: ------- *Comment #5 From Bart Van Assche 2007-07-18 07:12:49 * [reply] ------- I have downloaded the patch from http://kernel.ebshome.net/emac_slab_debug.diff, and I have tried it. Hereby I confirm that this patch solves the reported kernel oops. -- Regards, Bart Van Assche. ------=_Part_101522_6960589.1184784226940 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline On 7/18/07, Eugene Surovegin <ebs@ebshome.net> wrote:

It's kmalloc, at least this is how I think skbs are allocated.

Andrew, I don't have access to PPC hw right now (doing MIPS
development these days), so I cannot quickly check that my theory is
still correct for the latest kernel. I'd wait for the reporter to try
my hack and then we can decide what to do. IIRC there was some
provision in slab allocator to enforce alignment, when I was debugging
this problem more then a year ago, that option didn't work.

BTW, I think slob allocator had the same issue with alignment as slab
with enabled debugging (at least at the time I looked at it).


Hello Eugene,

In case you didn't notice yet, I have added the following comment to the kernel bugzilla item:


------- Comment #5 From Bart Van Assche 2007-07-18 07:12:49 [reply] -------
I have downloaded the patch from
http://kernel.ebshome.net/emac_slab_debug.diff, and I have tried it. Hereby I
confirm that this patch solves the reported kernel oops.


--
Regards,

Bart Van Assche. ------=_Part_101522_6960589.1184784226940-- --===============1603235888== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded --===============1603235888==--