From: Theodore Tso Subject: Re: upcoming kerneloops.org item: get_page_from_freelist Date: Thu, 25 Jun 2009 18:05:04 -0400 Message-ID: <20090625220504.GG6472@mit.edu> References: <20090624150714.c7264768.akpm@linux-foundation.org> <20090625132544.GB9995@mit.edu> <20090625193806.GA6472@mit.edu> <20090625194423.GB6472@mit.edu> <20090625203743.GD6472@mit.edu> <20090625212628.GO3385@webber.adilger.int> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Rientjes , Andrew Morton , Linus Torvalds , penberg@cs.helsinki.fi, arjan@infradead.org, linux-kernel@vger.kernel.org, cl@linux-foundation.org, npiggin@suse.de, linux-ext4@vger.kernel.org To: Andreas Dilger Return-path: Received: from thunk.org ([69.25.196.29]:46274 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753441AbZFYWF1 (ORCPT ); Thu, 25 Jun 2009 18:05:27 -0400 Content-Disposition: inline In-Reply-To: <20090625212628.GO3385@webber.adilger.int> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Jun 25, 2009 at 11:26:28PM +0200, Andreas Dilger wrote: > IIRC there was also a good reason for this in the past, related to > the buffers being submitted to the block device layer, and if they > were allocated from the slab cache with CONFIG_DEBUG_SLAB or something > similar enabled the buffer would be misaligned and cause grief. So what does SLAB/SLUB/SLOB do if we create a slab cache which is a power of two? Can one of the allocators still return misaligned blocks of memory in some circumstances? - Ted