Return-path: Received: from gir.skynet.ie ([193.1.99.77]:58361 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756133AbZINR7h (ORCPT ); Mon, 14 Sep 2009 13:59:37 -0400 Date: Mon, 14 Sep 2009 18:59:42 +0100 From: Mel Gorman To: Christoph Lameter Cc: Zhu Yi , "Chatre, Reinette" , Frans Pop , Larry Finger , "John W. Linville" , Pekka Enberg , "linux-kernel@vger.kernel.org" , "linux-wireless@vger.kernel.org" , "ipw3945-devel@lists.sourceforge.net" , Andrew Morton , "Krauss, Assaf" , Johannes Berg , "Abbas, Mohamed" Subject: Re: iwlagn: order 2 page allocation failures Message-ID: <20090914175942.GH11778@csn.ul.ie> References: <4AA67139.80301@lwfinger.net> <20090909150418.GI24614@csn.ul.ie> <200909091759.33655.elendil@planet.nl> <20090909165545.GK24614@csn.ul.ie> <1252526738.30150.91.camel@rc-desk> <20090910090206.GA22276@csn.ul.ie> <1252617290.30150.321.camel@rc-desk> <20090911084717.GB32497@csn.ul.ie> <1252897270.5650.169.camel@debian> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 In-Reply-To: Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, Sep 14, 2009 at 11:42:15AM -0400, Christoph Lameter wrote: > On Mon, 14 Sep 2009, Zhu Yi wrote: > > > BTW, does SLAB/SLUB guarantee size of multiple PAGE_SIZE __kmalloc() > > allocation align on PAGE_SIZE (or 256 bytes) boundary? > > Page allocators guarantee page aligned data. Slab allocators do not. > > You can create a slab that aligns objects on 256 byte boundary if you > want. > The allocation of buffers >= PAGE_SIZE even when allocated with kmalloc() are page-aligned though right? It's not an explicit guarantee but is it not always the case? -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab