[PATCH] linearly index zone->node_zonelists[]

I wonder why we need this bitmask indexing into zone->node_zonelists[]?

We always start with the highest zone and then include all lower zones
if we build zonelists.

Are there really cases where we need allocation from ZONE_DMA or
ZONE_HIGHMEM but not ZONE_NORMAL? It seems that the current implementation
of highest_zone() makes that already impossible.

If we go linear on the index then gfp_zone() == highest_zone() and a lot
of definitions fall by the wayside.

We can now revert back to the use of gfp_zone() in mempolicy.c ;-)

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 11 deletions

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index a0992d392d7..63ab88a36f3 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -12,9 +12,6 @@ struct vm_area_struct;
  *
  * Zone modifiers (see linux/mmzone.h - low three bits)
  *
- * These may be masked by GFP_ZONEMASK to make allocations with this bit
- * set fall back to ZONE_NORMAL.
- *
  * Do not put any conditional on these. If necessary modify the definitions
  * without the underscores and use the consistently. The definitions here may
  * be used in bit comparisons.
@@ -78,14 +75,7 @@ struct vm_area_struct;
 #define GFP_DMA32       __GFP_DMA32
 
 
-static inline int gfp_zone(gfp_t gfp)
-{
-        int zone = GFP_ZONEMASK & (__force int) gfp;
-        BUG_ON(zone >= GFP_ZONETYPES);
-        return zone;
-}
-
-static inline enum zone_type highest_zone(gfp_t flags)
+static inline enum zone_type gfp_zone(gfp_t flags)
 {
         if (flags & __GFP_DMA)
                 return ZONE_DMA;