[patch 1/5] mm: page_alloc: increase __GFP_BITS_SHIFT to include __GFP_OTHER_NODE

From: Johannes Weiner
Date: Mon Jul 25 2011 - 16:20:36 EST


From: Johannes Weiner <hannes@xxxxxxxxxxx>

__GFP_OTHER_NODE is used for NUMA allocations on behalf of other
nodes. It's supposed to be passed through from the page allocator to
zone_statistics(), but it never gets there as gfp_allowed_mask is not
wide enough and masks out the flag early in the allocation path.

The result is an accounting glitch where successful NUMA allocations
by-agent are not properly attributed as local.

Increase __GFP_BITS_SHIFT so that it includes __GFP_OTHER_NODE.

Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
---
include/linux/gfp.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index cb40892..3a76faf 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -92,7 +92,7 @@ struct vm_area_struct;
*/
#define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)

-#define __GFP_BITS_SHIFT 23 /* Room for 23 __GFP_FOO bits */
+#define __GFP_BITS_SHIFT 24 /* Room for N __GFP_FOO bits */
#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))

/* This equals 0, but use constants in case they ever change */
--
1.7.6

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