From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 24 May 2006 16:45:24 +0100 (BST) From: Hugh Dickins Subject: Re: Allow migration of mlocked pages In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: akpm@osdl.org, linux-mm@kvack.org, KAMEZAWA Hiroyuki List-ID: On Wed, 24 May 2006, Christoph Lameter wrote: > > I ran a test program that mlocked an array of pages and then migrated it > via sys_move_pages() and then verified what happened. Will run some more > stress tests today. > > ldso and glibc create some mlocked pages for each binary. If we do > migration with MPOL_MF_MOVE_ALL (common way of migrating pages) then > we usually will have to migrate VM_LOCKED pages of ldso and glibc. So > almost any testng of page migration will invariably involve migration of > VM_LOCKED pages. Oh, I'm not worried about whether ordinary VM_LOCKED pages will get migrated properly, I can't see any problem with that. It's whether something somewhere is using mlock and somehow relying on the physical pages to be pinned. I don't know what form that "somehow" would take, and I'm not saying there is or can be any such thing: just worried that we want wide exposure yet few testers migrate. Hugh -- 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