Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758083Ab2HJOMz (ORCPT ); Fri, 10 Aug 2012 10:12:55 -0400 Received: from nlpi157.sbcis.sbc.com ([207.115.36.171]:45590 "EHLO nlpi157.prodigy.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757618Ab2HJOMt (ORCPT ); Fri, 10 Aug 2012 10:12:49 -0400 Date: Fri, 10 Aug 2012 09:12:25 -0500 (CDT) From: "Christoph Lameter (Open Source)" X-X-Sender: cl@greybox.home To: Hanjun Guo cc: Wu Jianguo , Jiang Liu , Tony Luck , Pekka Enberg , Matt Mackall , Mel Gorman , Yinghai Lu , KAMEZAWA Hiroyuki , KOSAKI Motohiro , David Rientjes , Minchan Kim , Keping Chen , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jiang Liu Subject: Re: [RFC PATCH] mm: introduce N_LRU_MEMORY to distinguish between normal and movable memory In-Reply-To: <5024CADC.1010202@huawei.com> Message-ID: References: <1344482788-4984-1-git-send-email-guohanjun@huawei.com> <50233EF5.3050605@huawei.com> <5024CADC.1010202@huawei.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1826 Lines: 42 On Fri, 10 Aug 2012, Hanjun Guo wrote: > On 2012/8/9 22:06, Christoph Lameter (Open Source) wrote: > > On Thu, 9 Aug 2012, Hanjun Guo wrote: > > > >> Now, We have node masks for both N_NORMAL_MEMORY and > >> N_HIGH_MEMORY to distinguish between normal and highmem on platforms such as x86. > >> But we still don't have such a mechanism to distinguish between "normal" and "movable" > >> memory. > > > > What is the exact difference that you want to establish? > > Hi Christoph, > Thanks for your comments very much! > > We want to identify the node only has ZONE_MOVABLE memory. > for example: > node 0: ZONE_DMA, ZONE_DMA32, ZONE_NORMAL--> N_LRU_MEMORY, N_NORMAL_MEMORY > node 1: ZONE_MOVABLE --> N_LRU_MEMORY > thus, in SLUB allocator, will not allocate memory control structures for node1. So this would change the N_NORMAL_MEMORY definition so that N_NORMAL means !LRU allocs possible? So far N_NORMAL_MEMORY has a wider scope of meaning. We need an accurate definition of the meaning of all these attributes. > > For the slab case that you want to solve here you will need to know if the > > node has *only* movable memory and will never have any ZONE_NORMAL memory. > > If so then memory control structures for allocators that do not allow > > movable memory will not need to be allocated for these node. The node can > > be excluded from handling. > > I think this is what we are trying to do in this patch. > did I miss something? THe meaning of ZONE_NORMAL seems to change which causes confusion. Please describe in detail what each of these attributes mean. -- 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/