Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261887AbVEPV0C (ORCPT ); Mon, 16 May 2005 17:26:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261891AbVEPVWg (ORCPT ); Mon, 16 May 2005 17:22:36 -0400 Received: from dvhart.com ([64.146.134.43]:60065 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S261887AbVEPVVG (ORCPT ); Mon, 16 May 2005 17:21:06 -0400 Date: Mon, 16 May 2005 14:21:01 -0700 From: "Martin J. Bligh" Reply-To: "Martin J. Bligh" To: Jesse Barnes Cc: Christoph Lameter , Dave Hansen , Andy Whitcroft , Andrew Morton , linux-mm , Linux Kernel Mailing List , shai@scalex86.org, steiner@sgi.com Subject: Re: NUMA aware slab allocator V3 Message-ID: <740100000.1116278461@flay> In-Reply-To: <200505161410.43382.jbarnes@virtuousgeek.org> References: <714210000.1116266915@flay> <200505161410.43382.jbarnes@virtuousgeek.org> X-Mailer: Mulberry/2.1.2 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1304 Lines: 29 > Right, the SGI boxes have discontiguous memory within a node, but it's > not represented by pgdats (like you said, one 'virtual memmap' spans > the whole address space of a node). Sparse can help simplify this > across platforms, but has the potential to be more expensive for > systems with dynamically sized holes, due to the additional calculation > and potential cache miss associated with indexing into the correct > memmap (Dave can probably correct me here, it's been awhile). With a > virtual memmap, you only occasionally take a TLB miss on the struct > page access after indexing into the array. That's exactly what was brilliant about Andy's code ... it fixed that, there shouldn't be extra references ... >> transition config options are a bit of a mess ... Andy, I presume >> CONFIG_NEED_MULTIPLE_NODES is really CONFIG_NEED_MULTIPLE_PGDATS ? > > Yeah, makes sense for the NUMA aware slab allocator to depend on > CONFIG_NUMA. Andy confirmed offline that this is really CONFIG_NEED_MULTIPLE_PGDATS, and is just named wrong. M. - 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/