From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx133.postini.com [74.125.245.133]) by kanga.kvack.org (Postfix) with SMTP id 2DC358D0001 for ; Fri, 11 May 2012 12:20:49 -0400 (EDT) Date: Fri, 11 May 2012 11:20:44 -0500 (CDT) From: Christoph Lameter Subject: Re: Allow migration of mlocked page? In-Reply-To: <1336728026.1017.7.camel@twins> Message-ID: References: <4FAC9786.9060200@kernel.org> <1336728026.1017.7.camel@twins> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: Minchan Kim , Johannes Weiner , Mel Gorman , Rik van Riel , Andrew Morton , Andrea Arcangeli , KAMEZAWA Hiroyuki , "linux-mm@kvack.org" , tglx@linutronix.de, Ingo Molnar , Theodore Ts'o On Fri, 11 May 2012, Peter Zijlstra wrote: > On Fri, 2012-05-11 at 13:37 +0900, Minchan Kim wrote: > > I hope hear opinion from rt guys, too. > > Its a problem yes, not sure your solution is any good though. As it > stands mlock() simply doesn't guarantee no faults, all it does is > guarantee no major faults. There are two different way to lock pages down in memory that have different counters in /proc//status and also different semantics. VmLck: Mlocked pages. This means there is a prohibition against evicting pages. These pages can undergo page migration and therefore also be handled by compation. These pages have PG_mlock set. VmPin: Pinned pages. Page cannot be moved. These pages have an elevated refcount that makes page migration fail. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org