From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 9 Nov 2007 11:58:20 -0800 (PST) From: Christoph Lameter Subject: Re: about page migration on UMA In-Reply-To: <6934efce0711091154x74fe4405q5a9e291b3d9780f0@mail.gmail.com> Message-ID: References: <20071016191949.cd50f12f.kamezawa.hiroyu@jp.fujitsu.com> <20071016192341.1c3746df.kamezawa.hiroyu@jp.fujitsu.com> <20071017141609.0eb60539.kamezawa.hiroyu@jp.fujitsu.com> <20071017145009.e4a56c0d.kamezawa.hiroyu@jp.fujitsu.com> <02f001c8108c$a3818760$3708a8c0@arcapub.arca.com> <6934efce0711091131n1acd2ce1h7bb17f9f3cb0f235@mail.gmail.com> <6934efce0711091154x74fe4405q5a9e291b3d9780f0@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Jared Hulbert Cc: "Jacky(GuangXiang Lee)" , linux-mm@kvack.org, Yasunori Goto , KAMEZAWA Hiroyuki List-ID: On Fri, 9 Nov 2007, Jared Hulbert wrote: > On 11/9/07, Christoph Lameter wrote: > > On Fri, 9 Nov 2007, Jared Hulbert wrote: > > > > > For extreme low power systems it would be possible to shut down banks > > > in SDRAM chips that were not full thereby saving power. That would > > > require some defraging and migration to empty them prior to powering > > > down those banks. > > > > Yes we have discussed ideas like that a couple of time. If you do have the > > time then please make this work. You have my full support. > > So I would like to make this migration controlled by userspace. Are > there mechanisms to allow that today? If you give me a starting point > I'll look into something like this. Well one idea is to generate a sysfs file that can take a physical memory range? echo the range to the sysfs file. The kernel can then try to vacate the memory range. I am ccing the memory hotplug developers. They may be able to help you better. -- 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