Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754479AbYKDHET (ORCPT ); Tue, 4 Nov 2008 02:04:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752157AbYKDHEI (ORCPT ); Tue, 4 Nov 2008 02:04:08 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:44764 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752116AbYKDHEH (ORCPT ); Tue, 4 Nov 2008 02:04:07 -0500 From: "Rafael J. Wysocki" To: Nigel Cunningham Subject: Re: [linux-pm] [PATCH] hibernation should work ok with memory hotplug Date: Tue, 4 Nov 2008 08:08:35 +0100 User-Agent: KMail/1.9.9 Cc: Dave Hansen , Matt Tolentino , linux-pm@lists.osdl.org, Dave Hansen , linux-kernel@vger.kernel.org, linux-mm@kvack.org, pavel@suse.cz, Mel Gorman , Andy Whitcroft , Andrew Morton References: <20081029105956.GA16347@atrey.karlin.mff.cuni.cz> <1225751665.12673.511.camel@nimitz> <1225771353.6755.16.camel@nigel-laptop> In-Reply-To: <1225771353.6755.16.camel@nigel-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200811040808.36464.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1338 Lines: 34 On Tuesday, 4 of November 2008, Nigel Cunningham wrote: > Hi. > > On Mon, 2008-11-03 at 14:34 -0800, Dave Hansen wrote: > > A node might have a node_start_pfn=0 and a node_end_pfn=100 (and it may > > have only one zone). But, there may be another node with > > node_start_pfn=10 and a node_end_pfn=20. This loop: > > > > for_each_zone(zone) { > > ... > > for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) > > if (page_is_saveable(zone, pfn)) > > memory_bm_set_bit(orig_bm, pfn); > > } > > > > will walk over the smaller node's pfn range multiple times. Is this OK? > > > > I think all you have to do to fix it is check page_zone(page) == zone > > and skip out if they don't match. > > So pfn 10 in the first node refers to the same memory as pfn 10 in the > second node? A pfn always refers to specific page frame and/or struct page, so yes. However, in one of the nodes these pfns are sort of "invalid" (they point to struct pages belonging to other zones). AFAICS. Thanks, Rafael -- 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/