From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx148.postini.com [74.125.245.148]) by kanga.kvack.org (Postfix) with SMTP id D42586B0062 for ; Wed, 31 Oct 2012 14:16:38 -0400 (EDT) Received: by mail-pa0-f41.google.com with SMTP id fa10so1278363pad.14 for ; Wed, 31 Oct 2012 11:16:38 -0700 (PDT) Date: Wed, 31 Oct 2012 11:16:35 -0700 (PDT) From: David Rientjes Subject: Re: [PART3 Patch 00/14] introduce N_MEMORY In-Reply-To: <1351670652-9932-1-git-send-email-wency@cn.fujitsu.com> Message-ID: References: <1351670652-9932-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Wen Congyang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, Rob Landley , Andrew Morton , Yasuaki Ishimatsu , Lai Jiangshan , Jiang Liu , KOSAKI Motohiro , Minchan Kim , Mel Gorman , Yinghai Lu , "rusty@rustcorp.com.au" On Wed, 31 Oct 2012, Wen Congyang wrote: > From: Lai Jiangshan > > This patch is part3 of the following patchset: > https://lkml.org/lkml/2012/10/29/319 > > Part1 is here: > https://lkml.org/lkml/2012/10/31/30 > > Part2 is here: > http://marc.info/?l=linux-kernel&m=135166705909544&w=2 > > You can apply this patchset without the other parts. > > we need a node which only contains movable memory. This feature is very > important for node hotplug. So we will add a new nodemask > for all memory. N_MEMORY contains movable memory but N_HIGH_MEMORY > doesn't contain it. > > We don't remove N_HIGH_MEMORY because it can be used to search which > nodes contains memory that the kernel can use. > This doesn't describe why we need the new node state, unfortunately. It makes sense to boot with node(s) containing only ZONE_MOVABLE, but it doesn't show why we need a nodemask to specify such nodes and such information should be available from the kernel log or /proc/zoneinfo. Node hotplug should fail if all memory cannot be offlined, so why do we need another nodemask? Only offline the node if all memory is offlined. -- 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