From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 13 Feb 2008 15:38:29 +0000 From: Mel Gorman Subject: Re: [Bug 9941] New: Zone "Normal" missing in /proc/zoneinfo Message-ID: <20080213153829.GB1328@csn.ul.ie> References: <20080212100623.4fd6cf85.akpm@linux-foundation.org> <20080212234522.24bed8c1.akpm@linux-foundation.org> <20080213115225.GB4007@csn.ul.ie> <20080213152302.GA32416@shadowen.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20080213152302.GA32416@shadowen.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andy Whitcroft Cc: Andrew Morton , Bart Van Assche , bugme-daemon@bugzilla.kernel.org, linux-mm@kvack.org List-ID: On (13/02/08 15:23), Andy Whitcroft didst pronounce: > On Wed, Feb 13, 2008 at 11:52:25AM +0000, Mel Gorman wrote: > > > > > > > $ grep zone /proc/zoneinfo > > > > > > > > > > > > Output with 2.6.24: > > > > > > Node 0, zone DMA > > > > > > Node 0, zone DMA32 > > > > > > Node 0, zone Normal > > > > > > > > > > > > Output with 2.6.24.2: > > > > > > Node 0, zone DMA > > > > > > Node 0, zone DMA32 > > > > > > > > > > The greater surprise to me is that "Normal" ever appeared. The zone is empty, > > why is information appearing about it? I checked the dmesg for an x86_64 > > machine with 1GB of RAM that was running 2.6.24 here and there is no sign > > of Normal. > > > > mel@arnold:/tmp$ grep zone zoneinfo.before > > Node 0, zone DMA > > Node 0, zone DMA32 > > > > The loop looks like > > > > for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { > > if (!populated_zone(zone)) > > continue; > > > > It makes no sense for it to show up *unless* 2.6.24 was compiled as a 32 > > bit kernel by accident. Could this be the case? > > Interestingly I would not expect to see DMA32 at all if the kernel was > compiled 32 bit as CONFIG_DMA32 defaults to X86_64. > D'oh, of course. This couldn't have been a 32 bit kernel. > Could we simply have less ram detected/present in this boot. That would > make the zone dissappear if it became empty. > > The e820 output as reported by the old and new kernels would confirm the > memory size is detected the same. Also some idea of how much memory is > supposed be in the machine might shed some light. If the overall is near > to 4GB it may be remapping for the AGP apature or something similar which > is shifting memory up above the boundary. > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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