From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: Page allocator: Single Zone optimizations Date: Sat, 28 Oct 2006 09:12:01 -0700 References: <20061027214324.4f80e992.akpm@osdl.org> In-Reply-To: <20061027214324.4f80e992.akpm@osdl.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200610280912.01547.ak@suse.de> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Christoph Lameter , Nick Piggin , KAMEZAWA Hiroyuki , linux-mm@kvack.org List-ID: > It's all pretty simple. But it'd be hacky to implement it in terms of > "highmem". It would be better if we could just tell the core MM "here's a > 4G zone" and "here's a 60G zone". The 60G zone is only used for > GFP_HIGHUSER allocations and is hence unpluggable. > > I don't think there's any other (practical) way of implementing hot-unplug. If it's implemented this way it would be important that the boundaries between nodes are not fixed, but tunable. Otherwise kernel memory intensive loads might be suddenly impossible. > > But hot-unplug is just an example. My main point here is that it is > desirable that we get away from the up-to-four magical hard-wired zones in > core MM. I mostly agree. At least GFP_DMA needs to go and replaced with some API that gives memory masks and lets an underlying allocator figure it out. GFP_DMA32 might still have a better case though because those are pretty common, but ultimatively a mask based interface is here much better too. -Andi -- 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