Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751281AbaLROwn (ORCPT ); Thu, 18 Dec 2014 09:52:43 -0500 Received: from resqmta-po-08v.sys.comcast.net ([96.114.154.167]:37939 "EHLO resqmta-po-08v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751108AbaLROwm (ORCPT ); Thu, 18 Dec 2014 09:52:42 -0500 Date: Thu, 18 Dec 2014 08:52:40 -0600 (CST) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Dave Hansen cc: Fenghua Yu , Thomas Gleixner , "H. Peter Anvin" , Ingo Molnar , Glenn Williamson , linux-kernel , x86 Subject: Re: [PATCH v2] X86-32: Allocate 256 bytes for pgd in PAE paging In-Reply-To: <54921EF2.9070004@intel.com> Message-ID: References: <1418852859-18852-1-git-send-email-fenghua.yu@intel.com> <54921EF2.9070004@intel.com> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 17 Dec 2014, Dave Hansen wrote: > IOW, do *ALL* of the sl*b allocators in all of their forms with all of > their debugging options guarantee 32-byte alignment when allocating > 256-byte objects? No. For that the arch has to set a macro call ARCH_KMALLOC_MINALIGN or ARCH_DMA_MINALIGN. Default alignment is to a word boundary. > I know we at least try to align to a cacheline, which would be good > enough, but I'm fuzzy on what we *guarantee*. Sorry we only do this if requested for a slab cache. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/