Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759357AbYCEU44 (ORCPT ); Wed, 5 Mar 2008 15:56:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755515AbYCEU4p (ORCPT ); Wed, 5 Mar 2008 15:56:45 -0500 Received: from relay1.sgi.com ([192.48.171.29]:59522 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755267AbYCEU4o (ORCPT ); Wed, 5 Mar 2008 15:56:44 -0500 Date: Wed, 5 Mar 2008 12:56:33 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Nick Piggin cc: Pekka Enberg , netdev@vger.kernel.org, Linux Kernel Mailing List , yanmin_zhang@linux.intel.com, David Miller , Eric Dumazet Subject: Re: [rfc][patch 1/3] slub: fix small HWCACHE_ALIGN alignment In-Reply-To: <20080305002821.GD1510@wotan.suse.de> Message-ID: References: <20080303093449.GA15091@wotan.suse.de> <20080303200613.GC8974@wotan.suse.de> <20080303201701.GF8974@wotan.suse.de> <84144f020803031330i2c0ea1f6kc5b02c8b26145797@mail.gmail.com> <47CC6F30.50802@cs.helsinki.fi> <20080305002821.GD1510@wotan.suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 943 Lines: 21 On Wed, 5 Mar 2008, Nick Piggin wrote: > It started out as a SLUB regression that was exposing poor code in the > percpu allocator due to different SLUB kmalloc alignments. That prompted That was due to SLUB's support for smaller allocation sizes. AFAICT has nothing to do with alignment. > The SMP flag was just an RFC. I think some people (like Christoph) were > being confused about the HWCACHE_ALIGN flag being for avoiding false > sharing on SMP systems. It would actually be also generally useful to > have the SMP flag (eg. see the sites I added it to in patch #3). Hmmm. We could define a global constant for that? Determine it on bootup and then pass it as an alignment parameter? -- 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/