Move the gfpflags masking into the hooks for checkers and into the slowpaths.
gfpflag masking requires access to a global variable and thus adds an
additional cacheline reference to the hotpaths.

If no hooks are active then the gfpflag masking will result in
code that the compiler can toss out.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>

---
 mm/slub.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2010-07-07 10:38:17.000000000 -0500
+++ linux-2.6/mm/slub.c	2010-07-07 10:38:22.000000000 -0500
@@ -798,6 +798,7 @@ static void trace(struct kmem_cache *s, 
  */
 static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
 {
+	flags &= gfp_allowed_mask;
 	lockdep_trace_alloc(flags);
 	might_sleep_if(flags & __GFP_WAIT);
 
@@ -806,6 +807,7 @@ static inline int slab_pre_alloc_hook(st
 
 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object)
 {
+	flags &= gfp_allowed_mask;
 	kmemcheck_slab_alloc(s, flags, object, s->objsize);
 	kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, flags);
 }
@@ -1648,6 +1650,7 @@ static void *__slab_alloc(struct kmem_ca
 
 	/* We handle __GFP_ZERO in the caller */
 	gfpflags &= ~__GFP_ZERO;
+	gfpflags &= gfp_allowed_mask;
 
 	if (!c->page)
 		goto new_slab;
@@ -1733,8 +1736,6 @@ static __always_inline void *slab_alloc(
 	struct kmem_cache_cpu *c;
 	unsigned long flags;
 
-	gfpflags &= gfp_allowed_mask;
-
 	if (!slab_pre_alloc_hook(s, gfpflags))
 		return NULL;
 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/