Re: parisc DISCONTIGMEM compile breakage

[James Bottomley <James.Bottomley@HansenPartnership.com>]

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 <mel@csn.ul.ie>
> ---
>  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.
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.

Therefore it seems what will give the original functionality back is
actually this:

James

diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 1f01284..7bc286d 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -602,15 +602,16 @@ void show_mem(void)
 
 #ifdef CONFIG_DISCONTIGMEM
 	{
-		struct zonelist *zl;
 		int i, j;
 
 		for (i = 0; i < npmem_ranges; i++) {
-			zl = node_zonelist(i);
 			for (j = 0; j < MAX_NR_ZONES; j++) {
+				struct zonelist *zl;
 				struct zoneref *z;
 				struct zone *zone;
 
+				zl = NODE_DATA(i)->node_zonelists + j;
+
 				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),