Re: [1/3] Add __GFP_THISNODE to avoid fallback to other nodes and ignore cpuset/memory policy restrictions.

[Christoph Lameter <clameter@sgi.com>]

On Thu, 10 Aug 2006, Andrew Morton wrote:

> This adds a little bit of overhead to non-numa kernels.  I think that
> overhead could be eliminated if we were to do

The overhead is really minimal. The parameter we are testing is passed on 
later and the test is unlikely.

I would rather avoid fiddling around with making __GFP_xxx conditional.
We have seen  to what problems this could lead. The #ifdef is less harmful
if placed in get_page_from_freelist.

How about this one:

Index: linux-2.6.18-rc3-mm2/mm/page_alloc.c
===================================================================
--- linux-2.6.18-rc3-mm2.orig/mm/page_alloc.c	2006-08-09 18:37:06.434599531 -0700
+++ linux-2.6.18-rc3-mm2/mm/page_alloc.c	2006-08-10 20:13:53.674465629 -0700
@@ -918,12 +918,14 @@ get_page_from_freelist(gfp_t gfp_mask, u
 	 */
 	do {
 		zone = *z;
+#ifdef CONFIG_NUMA
 		if (unlikely((gfp_mask & __GFP_THISNODE) &&
 			zone->zone_pgdat != zonelist->zones[0]->zone_pgdat))
 				break;
 		if ((alloc_flags & ALLOC_CPUSET) &&
 				!cpuset_zone_allowed(zone, gfp_mask))
 			continue;
+#endif
 
 		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
 			unsigned long mark;

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