From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 14 Aug 2007 12:33:30 -0700 (PDT) From: Christoph Lameter Subject: Re: Minor [?] page migration bug in check_pte_range() In-Reply-To: <1187105148.6281.38.camel@localhost> Message-ID: References: <1187105148.6281.38.camel@localhost> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Lee Schermerhorn Cc: Andi Kleen , Andrew Morton , linux-mm List-ID: On Tue, 14 Aug 2007, Lee Schermerhorn wrote: > What I see is that when you attempt to install an interleave policy and > migrate the pages to match that policy, any pages on nodes included in > the interleave node mask will not be migrated to match policy. This Right. The pages are already on permitted nodes. > occurs because of the clever, but overly simplistic test in > check_pte_range(): > > if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT)) > continue; > > Fixing this would, I think, involve checking each page against the > location dictated by the new policy. Altho' I don't think this is a > performance critical path, it is the inner-most loop of check_range(). > > Is this worth addressing, do you think? This is not going to be easy because you would have to move each individual pages to a particular node. Or setup lists for each node and then do several calls to migrate page. I think we can leave it as is. -- 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