From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932913AbYEFVSP (ORCPT ); Tue, 6 May 2008 17:18:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757851AbYEFVR4 (ORCPT ); Tue, 6 May 2008 17:17:56 -0400 Received: from gir.skynet.ie ([193.1.99.77]:53653 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757527AbYEFVRy (ORCPT ); Tue, 6 May 2008 17:17:54 -0400 Date: Tue, 6 May 2008 22:17:50 +0100 From: Mel Gorman To: James Bottomley Cc: Adrian Bunk , Christoph Lameter , Lee Schermerhorn , kyle@parisc-linux.org, matthew@wil.cx, grundler@parisc-linux.org, linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: parisc DISCONTIGMEM compile breakage Message-ID: <20080506211750.GA13214@csn.ul.ie> References: <20080506134648.GA30082@cs181133002.pp.htv.fi> <20080506152713.GA5034@csn.ul.ie> <1210103927.3057.19.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1210103927.3057.19.camel@localhost.localdomain> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (06/05/08 14:58), James Bottomley didst pronounce: > On Tue, 2008-05-06 at 16:27 +0100, Mel Gorman wrote: > > On (06/05/08 16:46), Adrian Bunk didst pronounce: > > > Commit 54a6eb5c4765aa573a030ceeba2c14e3d2ea5706 > > > (mm: use two zonelist that are filtered by GFP mask) > > > causes the following build error with CONFIG_DISCONTIGMEM=y > > > on parisc: > > > > > > > Thanks Adrian. I don't have a pa-risc cross-compiler and there isn't one > > at the usual source http://userweb.kernel.org/~akpm/cross-compilers but the > > patch below should fix it. Note that this debugging code should be deleted if > > the mm-initialisation-and-debugging framework in -mm is merged to mainline > > as it knows how to print all the zonelists where as the pa-risc equivilant > > misses the GFP_THISNODE lists. > > > > ===== > > Subject: [PATCH] Fix pa-risc DISCONTIGMEM compile breakage > > > > PA-RISC to aid debugging prints out the zonelists setup by the system. A > > bad call to node_zonelist() breaks at compile-time. This patch fixes it. > > > > Signed-off-by: Mel Gorman > > --- > > arch/parisc/mm/init.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c > > index 1f01284..b0ed709 100644 > > --- a/arch/parisc/mm/init.c > > +++ b/arch/parisc/mm/init.c > > @@ -606,7 +606,7 @@ void show_mem(void) > > int i, j; > > > > for (i = 0; i < npmem_ranges; i++) { > > - zl = node_zonelist(i); > > + zl = node_zonelist(i, 0); > > for (j = 0; j < MAX_NR_ZONES; j++) { > > This rather doesn't look right. The intent is for i to iterate over the > ranges (as nodes) and j to iterate over the zones to get the zonelist. Yes, that appears to be the original intention. > The original variable k was going over the mappings, which you replaced > with for_each_zone_zonelist. If you use node_zonelist(i, 0) you don't > really look at the actual zones in the map. > No, but you filter the one list based on the highest zone that can be accesssed. > Therefore it seems what will give the original functionality back is > actually this: > To be fair, a few weeks ago you would have been right. Since then zonelists have changed though so that there are only two zonelists per node in git-latest. One which is for general allocations and one for GFP_THISNODE. The zonelist is filtered based on the GFP flags, hence the iterator. I copied the parisc code with the compile-fix into mm/page_alloc.c and called it just to be sure and with qemu, I see [ 0.628960] Zone list for zone 0 on node 0: [0/DMA] [ 0.628960] Zone list for zone 1 on node 0: [0/Normal] [0/DMA] [ 0.628960] Zone list for zone 2 on node 0: [0/HighMem] [0/Normal] [0/DMA] [ 0.628960] Zone list for zone 3 on node 0: [0/Movable] [0/HighMem] [0/Normal] [0/DMA] which looks right (movablecore was specified hence the existance of the movable zone). > > for (j = 0; j < MAX_NR_ZONES; j++) { > + struct zonelist *zl; > struct zoneref *z; > struct zone *zone; > > + zl = NODE_DATA(i)->node_zonelists + j; > + This would read past the end of the node_zonelists array which is only MAX_ZONELISTS (2 for CONFIG_NUMA) in size. > printk("Zone list for zone %d on node %d: ", j, i); > for_each_zone_zonelist(zone, z, zl, j) > printk("[%d/%s] ", zone_to_nid(zone), > > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab