From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id A1F246B0071 for ; Wed, 3 Feb 2010 19:08:10 -0500 (EST) Date: Thu, 4 Feb 2010 09:07:56 +0900 From: Paul Mundt Subject: Re: [RFC] slub: ARCH_SLAB_MINALIGN defaults to 8 on x86_32. is this too big? Message-ID: <20100204000755.GA451@linux-sh.org> References: <1265206946.2118.57.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1265206946.2118.57.camel@localhost> Sender: owner-linux-mm@kvack.org To: Richard Kennedy Cc: Christoph Lameter , penberg , Ingo Molnar , Thomas Gleixner , lkml , linux-mm List-ID: On Wed, Feb 03, 2010 at 02:22:26PM +0000, Richard Kennedy wrote: > Can I define a ARCH_SLAB_MINALIGN in x86_64 to sizeof(void *) ? > or would it be ok to change the default in slub.c to sizeof(void *) ? > Note that this is precisely what ARCH_SLAB_MINALIGN was introduced to avoid (BYTES_PER_WORD alignment used to be the default for slab, before ARCH_SLAB_MINALIGN was introduced). Consider the case of 64-bit platforms using a 32-bit ABI, the native alignment remains 64-bit while sizeof(void *) == 4. There are a number of (mainly embedded) architectures that support these sorts of configurations in-tree. -- 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