From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 24 May 2006 09:09:11 -0700 (PDT) From: Christoph Lameter 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: Hugh Dickins Cc: akpm@osdl.org, linux-mm@kvack.org, KAMEZAWA Hiroyuki List-ID: On Wed, 24 May 2006, Hugh Dickins wrote: > 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. All of these driver mappings are installed using remap_pfn_page. These are mappings that are not considered by page migration at all because: 1. They are marked VM_PFNMAP and VM_IO. vma_migratable() checks for those. vmas so marked will not be scanned for pages to migrate. 2. No page struct exists. check_pte_range and do_move_pages will skip these entries. There will never be an attempt to migrate. -- 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