Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752090AbXA2Wpp (ORCPT ); Mon, 29 Jan 2007 17:45:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752091AbXA2Wpp (ORCPT ); Mon, 29 Jan 2007 17:45:45 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:49736 "EHLO omx2.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752090AbXA2Wpn (ORCPT ); Mon, 29 Jan 2007 17:45:43 -0500 Date: Mon, 29 Jan 2007 14:45:06 -0800 (PST) From: Christoph Lameter To: Andrew Morton cc: Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter Subject: Re: [PATCH 0/8] Create ZONE_MOVABLE to partition memory between movable and non-movable pages In-Reply-To: <20070129143654.27fcd4a4.akpm@osdl.org> Message-ID: References: <20070125234458.28809.5412.sendpatchset@skynet.skynet.ie> <20070126030753.03529e7a.akpm@osdl.org> <20070126114615.5aa9e213.akpm@osdl.org> <20070126122747.dde74c97.akpm@osdl.org> <20070129143654.27fcd4a4.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1309 Lines: 28 On Mon, 29 Jan 2007, Andrew Morton wrote: > > All 64 bit machine will only have a single zone if we have such a range > > alloc mechanism. The 32bit ones with HIGHMEM wont be able to avoid it, > > true. But all arches that do not need gymnastics to access their memory > > will be able run with a single zone. > > What is "such a range alloc mechanism"? As I mentioned above: A function that allows an allocation to specify which physical memory ranges are permitted. > So please stop telling me what a wonderful world it is to not have multiple > zones. It just isn't going to happen for a long long time. The > multiple-zone kernel is the case we need to care about most by a very large > margin indeed. Single-zone is an infinitesimal corner-case. We can still reduce the number of zones for those that require highmem to two which may allows us to avoid ZONE_DMA/DMA32 issues and allow dma devices to avoid bunce buffers that can do I/O to memory ranges not compatible with the current boundaries of DMA/DMA32. And I am also repeating myself. - 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/