From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f169.google.com (mail-pd0-f169.google.com [209.85.192.169]) by kanga.kvack.org (Postfix) with ESMTP id C179C6B0031 for ; Wed, 12 Feb 2014 02:08:49 -0500 (EST) Received: by mail-pd0-f169.google.com with SMTP id v10so8667580pde.28 for ; Tue, 11 Feb 2014 23:08:49 -0800 (PST) Received: from song.cn.fujitsu.com ([222.73.24.84]) by mx.google.com with ESMTP id gj4si21648756pac.147.2014.02.11.23.08.46 for ; Tue, 11 Feb 2014 23:08:48 -0800 (PST) Message-ID: <52FB1E96.5010509@cn.fujitsu.com> Date: Wed, 12 Feb 2014 15:11:18 +0800 From: Tang Chen MIME-Version: 1.0 Subject: Re: [PATCH RESEND part2 v2 1/8] x86: get pg_data_t's memory from other node References: <529D3FC0.6000403@cn.fujitsu.com> <529D4048.9070000@cn.fujitsu.com> <20140116171112.GB24740@suse.de> <52DCD065.7040408@cn.fujitsu.com> <20140120151409.GU4963@suse.de> <20140206101230.GA21345@suse.de> <52F86745.2060204@cn.fujitsu.com> <20140211110842.GI6732@suse.de> In-Reply-To: <20140211110842.GI6732@suse.de> Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-15; format=flowed Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Zhang Yanfei , Andrew Morton , Tejun Heo , Len Brown , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Toshi Kani , Wanpeng Li , Thomas Renninger , Yinghai Lu , Jiang Liu , Wen Congyang , Lai Jiangshan , Yasuaki Ishimatsu , Taku Izumi , Minchan Kim , "mina86@mina86.com" , "gong.chen@linux.intel.com" , Vasilis Liaskovitis , "lwoodman@redhat.com" , Rik van Riel , "jweiner@redhat.com" , Prarit Bhargava , "linux-kernel@vger.kernel.org" , Linux MM , Chen Tang , Zhang Yanfei Hi Mel, On 02/11/2014 07:08 PM, Mel Gorman wrote: ...... >>>> I think they should be warned if the ratio is high and have an option of >>>> specifying a ratio manually even if that means that additional nodes >>>> will not be hot-removable. >> >> I think this is easy to do, provide an option for users to specify a >> Normal:Movable ratio. This is not phys addr, and it is easy to use. >> > > Yes. It would even be some help if the parameter forced some NUMA nodes > to be Normal instead of Movable regardless of what SRAT says. There > still would be an administrative burden in discovering what nodes are > now pluggable but they must have been dealing with this already. > OK, I will start this work, and send patches soon. >>>> >>>> This is all still a kludge around the fact that node memory hot-remove >>>> did not try and cope with full migration by breaking some of the 1:1 >>>> virt:phys mapping assumptions when hot-remove was enabled. >> >> I also said before, the implementation now can only be a temporary >> solution for memory hotplug since it would take us a lot of time to >> deal with 1:1 mapping thing. >> >> But about "breaking some of the 1:1 mapping", would you please give me >> any hint of it ? I want to do it too, but I cannot see where to start. >> > > Some hints on how it might be tackled were given back in November 2012 > https://lkml.org/lkml/2012/11/29/190 but I never researched it in > detail. > Thank you very much. I will read it one more time, and start trying to migrate some of the kernel pages first. Thanks. -- 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