Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932361AbWAKGTE (ORCPT ); Wed, 11 Jan 2006 01:19:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932366AbWAKGTE (ORCPT ); Wed, 11 Jan 2006 01:19:04 -0500 Received: from omx1-ext.sgi.com ([192.48.179.11]:14468 "EHLO omx1.americas.sgi.com") by vger.kernel.org with ESMTP id S932361AbWAKGTC (ORCPT ); Wed, 11 Jan 2006 01:19:02 -0500 Date: Tue, 10 Jan 2006 22:18:46 -0800 (PST) From: Christoph Lameter To: akpm@osdl.org cc: KAMEZAWA Hiroyuki , Cliff Wickman , linux-kernel@vger.kernel.org, lhms-devel@lists.sourceforge.net, Hirokazu Takahashi Subject: Re: [PATCH 0/5] Direct Migration V9: Overview In-Reply-To: <43C47AD9.10800@jp.fujitsu.com> Message-ID: References: <20060110224114.19138.10463.sendpatchset@schroedinger.engr.sgi.com> <43C47AD9.10800@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1368 Lines: 32 On Wed, 11 Jan 2006, KAMEZAWA Hiroyuki wrote: > I think current limitation is just Hugetlb pages and mlocked pages. right ? > Could you make it clear and add comment or doc before going to -mm ? These are checked by the code in mm/mempolicy.c. Add some comments to migrate_pages() stating the limitations. Signed-off-by: Christoph Lameter Index: linux-2.6.15/mm/vmscan.c =================================================================== --- linux-2.6.15.orig/mm/vmscan.c 2006-01-10 22:13:37.000000000 -0800 +++ linux-2.6.15/mm/vmscan.c 2006-01-10 22:16:45.000000000 -0800 @@ -842,6 +842,12 @@ EXPORT_SYMBOL(migrate_page); * are movable anymore because t has become empty * or no retryable pages exist anymore. * + * Limitations: + * Cannot migrate mlocked pages because there is a danger + * that those may be swapped out. Also cannot migrate + * huge pages. We also cannot migrate pages of VMA's with + * special attributes (VM_IO, VM_LOCKED, VM_PFNMAP). + * * Return: Number of pages not migrated when "to" ran empty. */ int migrate_pages(struct list_head *from, struct list_head *to, - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/