From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 13 Feb 2008 11:52:25 +0000 From: Mel Gorman Subject: Re: [Bug 9941] New: Zone "Normal" missing in /proc/zoneinfo Message-ID: <20080213115225.GB4007@csn.ul.ie> References: <20080212100623.4fd6cf85.akpm@linux-foundation.org> <20080212234522.24bed8c1.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20080212234522.24bed8c1.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Bart Van Assche , bugme-daemon@bugzilla.kernel.org, linux-mm@kvack.org List-ID: On (12/02/08 23:45), Andrew Morton didst pronounce: > On Wed, 13 Feb 2008 08:39:30 +0100 "Bart Van Assche" wrote: > > > On Feb 12, 2008 7:06 PM, Andrew Morton wrote: > > > > > > On Tue, 12 Feb 2008 02:39:40 -0800 (PST) bugme-daemon@bugzilla.kernel.org wrote: > > > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=9941 > > > > > > > > Summary: Zone "Normal" missing in /proc/zoneinfo > > > > Product: Memory Management > > > > Version: 2.5 > > > > KernelVersion: 2.6.24.2 > > > > Platform: All > > > > OS/Version: Linux > > > > Tree: Mainline > > > > Status: NEW > > > > Severity: normal > > > > Priority: P1 > > > > Component: Other > > > > AssignedTo: akpm@osdl.org > > > > ReportedBy: bart.vanassche@gmail.com > > > > > > > > > > > > Latest working kernel version: 2.6.24 > > > > Earliest failing kernel version: 2.6.24.2 > > > > Distribution: Ubuntu 7.10 server > > > > Hardware Environment: Intel S5000PAL > > > > Software Environment: > > > > Problem Description: > > > > > > > > There is only information about the zones "DMA" and "DMA32" in /proc/zoneinfo, > > > > not about zone "Normal". > > > > > > > > Steps to reproduce: > > > > > > > > Run the following command in a shell: > > > > $ 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? > > > > Zone PFN ranges: > > DMA 0 -> 4096 > > DMA32 4096 -> 1048576 > > Normal 1048576 -> 1048576 > > Movable zone start PFN for each node > > early_node_map[6] active PFN ranges > > 0: 0 -> 159 > > 0: 256 -> 516825 > > 0: 517019 -> 522802 > > 0: 522906 -> 522956 > > 0: 523034 -> 523046 > > 0: 523066 -> 523264 > > On node 0 totalpages: 522771 > > DMA zone: 96 pages used for memmap > > DMA zone: 2170 pages reserved > > DMA zone: 1733 pages, LIFO batch:0 > > DMA32 zone: 12168 pages used for memmap > > DMA32 zone: 506604 pages, LIFO batch:31 > > Normal zone: 0 pages used for memmap > > Movable zone: 0 pages used for memmap > > OK, that machine really has no ZONE_NORMAL. I didn't know we do that. > On x86_64 (which is what it is according to the config), machines with less than 4GB of RAM will have no ZONE_NORMAL. This machine appears to have 2GB. I don't see the problem as such because it's like PPC64 only having ZONE_DMA (ZONE_NORMAL exists but it is always empty). > Mel, is this, uh, normal? > On x86_64, it is. -- 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