From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932122AbWGCXr0 (ORCPT ); Mon, 3 Jul 2006 19:47:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932292AbWGCXr0 (ORCPT ); Mon, 3 Jul 2006 19:47:26 -0400 Received: from ns.suse.de ([195.135.220.2]:48527 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S932122AbWGCXrZ (ORCPT ); Mon, 3 Jul 2006 19:47:25 -0400 From: Andi Kleen To: Christoph Lameter Subject: Re: [RFC 0/8] Reduce MAX_NR_ZONES and remove useless zones. Date: Tue, 4 Jul 2006 01:47:10 +0200 User-Agent: KMail/1.9.3 Cc: Christoph Hellwig , linux-kernel@vger.kernel.org, akpm@osdl.org, Hugh Dickins , Con Kolivas , Marcelo Tosatti , Nick Piggin References: <20060703215534.7566.8168.sendpatchset@schroedinger.engr.sgi.com> <20060703221712.GB14273@infradead.org> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200607040147.10995.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > So we want to change the definition of ZONE_DMA to refer to the first 16MB > only? ZONE_DMA32 is always a 4GB border? (Andy disagrees about DMA32 see > his message!). Hmm? I didn't write anything about DMA32. Just noted a minor comment thinko about highmem. > It seems to me that DMA can be run on ZONE_NORMAL. ZONE_DMAxx is used for > situations in which DMA cannot be done to all of memory. ZONE_DMA allows > an architecture to define a single exception zone that ends at > MAX_DMA_ADDRESS (which is arch specific). It's really architecture dependent. The portable interfaces are dma_alloc_* and suitable device masks and the architecture should sort out then what zone to use. I would say nearly everybody who uses GFP_DMA directly outside {arch,asm}/* is wrong. -Andi