From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f178.google.com (mail-lb0-f178.google.com [209.85.217.178]) by kanga.kvack.org (Postfix) with ESMTP id 1FDF76B0031 for ; Tue, 1 Jul 2014 22:06:56 -0400 (EDT) Received: by mail-lb0-f178.google.com with SMTP id 10so7493746lbg.37 for ; Tue, 01 Jul 2014 19:06:55 -0700 (PDT) Received: from e28smtp07.in.ibm.com (e28smtp07.in.ibm.com. [122.248.162.7]) by mx.google.com with ESMTPS id kr7si21179784lac.39.2014.07.01.19.06.53 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 01 Jul 2014 19:06:54 -0700 (PDT) Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 2 Jul 2014 07:36:50 +0530 Received: from d28relay01.in.ibm.com (d28relay01.in.ibm.com [9.184.220.58]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 838A6E0044 for ; Wed, 2 Jul 2014 07:38:07 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s622888j62980298 for ; Wed, 2 Jul 2014 07:38:09 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s6226l43022774 for ; Wed, 2 Jul 2014 07:36:47 +0530 Date: Wed, 2 Jul 2014 10:06:46 +0800 From: Wei Yang Subject: Re: mm: slub: invalid memory access in setup_object Message-ID: <20140702020646.GB6961@richard> Reply-To: Wei Yang References: <53AAFDF7.2010607@oracle.com> <20140701144947.5ce3f93729759d8f38d7813a@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140701144947.5ce3f93729759d8f38d7813a@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Christoph Lameter , David Rientjes , Sasha Levin , Wei Yang , Pekka Enberg , Matt Mackall , "linux-mm@kvack.org" , LKML , Dave Jones On Tue, Jul 01, 2014 at 02:49:47PM -0700, Andrew Morton wrote: >On Tue, 1 Jul 2014 09:58:52 -0500 (CDT) Christoph Lameter wrote: > >> On Mon, 30 Jun 2014, David Rientjes wrote: >> >> > It's not at all clear to me that that patch is correct. Wei? >> >> Looks ok to me. But I do not like the convoluted code in new_slab() which >> Wei's patch does not make easier to read. Makes it difficult for the >> reader to see whats going on. >> >> Lets drop the use of the variable named "last". >> >> >> Subject: slub: Only call setup_object once for each object >> >> Modify the logic for object initialization to be less convoluted >> and initialize an object only once. >> > >Well, um. Wei's changelog was much better: > >: When a kmem_cache is created with ctor, each object in the kmem_cache will >: be initialized before use. In the slub implementation, the first object >: will be initialized twice. >: >: This patch avoids the duplication of initialization of the first object. >: >: Fixes commit 7656c72b5a63: ("SLUB: add macros for scanning objects in a >: slab"). > >I can copy that text over and add the reported-by etc (ho hum) but I >have a tiny feeling that this patch hasn't been rigorously tested? >Perhaps someone (Wei?) can do that? Ok, I will apply this one and give a shot. > >And we still don't know why Sasha's kernel went oops. Yep, if there is some procedure to reproduce it, I'd like to do it at my side. -- Richard Yang Help you, Help me -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org