From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 29 Jan 2007 14:45:06 -0800 (PST) From: 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: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter List-ID: 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, 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