From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx125.postini.com [74.125.245.125]) by kanga.kvack.org (Postfix) with SMTP id 549A66B00C1 for ; Fri, 30 Nov 2012 10:37:03 -0500 (EST) Received: by mail-pb0-f41.google.com with SMTP id xa7so532856pbc.14 for ; Fri, 30 Nov 2012 07:37:02 -0800 (PST) Message-ID: <50B8D288.4080204@gmail.com> Date: Fri, 30 Nov 2012 23:36:40 +0800 From: Jiang Liu MIME-Version: 1.0 Subject: Re: [PATCH v2 0/5] Add movablecore_map boot option References: <1353667445-7593-1-git-send-email-tangchen@cn.fujitsu.com> <50B5CFAE.80103@huawei.com> <3908561D78D1C84285E8C5FCA982C28F1C95EDCE@ORSMSX108.amr.corp.intel.com> <50B68467.5020008@zytor.com> <20121129110045.GX8218@suse.de> <50B82064.9000405@huawei.com> <50B824DE.40702@jp.fujitsu.com> In-Reply-To: <50B824DE.40702@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Yasuaki Ishimatsu Cc: Jiang Liu , Mel Gorman , "H. Peter Anvin" , "Luck, Tony" , Tang Chen , "akpm@linux-foundation.org" , "rob@landley.net" , "laijs@cn.fujitsu.com" , "wency@cn.fujitsu.com" , "linfeng@cn.fujitsu.com" , "yinghai@kernel.org" , "kosaki.motohiro@jp.fujitsu.com" , "minchan.kim@gmail.com" , "rientjes@google.com" , "rusty@rustcorp.com.au" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-doc@vger.kernel.org" , Len Brown , "Wang, Frank" On 11/30/2012 11:15 AM, Yasuaki Ishimatsu wrote: > Hi Jiang, > >> >> For the first issue, I think we could automatically convert pages >> from movable zones into normal zones. Congyan from Fujitsu has provided >> a patchset to manually convert pages from movable zones into normal zones, >> I think we could extend that mechanism to automatically convert when >> normal zones are under pressure by hooking into the slow page allocation >> path. >> >> We rely on hardware features to solve the second and third issues. >> Some new platforms provide a new RAS feature called "hardware memory >> migration", which transparent migrate memory from one memory device >> to another. With hardware memory migration, we could configure one >> memory device on a NUMA node to host normal zone, and the other memory >> devices to host movable zone. By this configuration, it won't cause >> performance drop because each NUMA node still has local normal zone. >> When trying to remove a memory device hosting normal zone, we just >> need to find another spare memory device and use hardware memory migration >> to transparently migrate memory content to the spare one. The drawback >> is we have strong dependency on hardware features so it's not a common >> solution for all architectures. > > I agree with you. If BIOS and hardware support memory hotplug, OS should > use them. But if OS cannot use them, we need to solve in OS. I think > that our proposal which used ZONE_MOVABLE is first step for supporting > memory hotplug. Hi Yasuaki, It's true, we should start with first step then improve it. Regards! Gerry -- 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