[Slub cleanup 8/9] slub: Use page variable instead of c->page.

[Christoph Lameter <cl@xxxxxxxxx>]

Store the value of c->page to avoid additional fetches
from per cpu data.

Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>


---
 mm/slub.c |   17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2012-01-13 08:47:31.930748367 -0600
+++ linux-2.6/mm/slub.c	2012-01-13 08:47:35.018748303 -0600
@@ -2183,6 +2183,7 @@ static void *__slab_alloc(struct kmem_ca
 			  unsigned long addr, struct kmem_cache_cpu *c)
 {
 	void *freelist;
+	struct page *page;
 	unsigned long flags;
 
 	local_irq_save(flags);
@@ -2195,13 +2196,14 @@ static void *__slab_alloc(struct kmem_ca
 	c = this_cpu_ptr(s->cpu_slab);
 #endif
 
-	if (!c->page)
+	page = c->page;
+	if (!page)
 		goto new_slab;
 redo:
 
 	if (unlikely(!node_match(c, node))) {
 		stat(s, ALLOC_NODE_MISMATCH);
-		deactivate_slab(s, c->page, c->freelist);
+		deactivate_slab(s, page, c->freelist);
 		c->page = NULL;
 		c->freelist = NULL;
 		goto new_slab;
@@ -2214,7 +2216,7 @@ redo:
 
 	stat(s, ALLOC_SLOWPATH);
 
-	freelist = get_freelist(s, c->page);
+	freelist = get_freelist(s, page);
 
 	if (!freelist) {
 		c->page = NULL;
@@ -2239,8 +2241,8 @@ load_freelist:
 new_slab:
 
 	if (c->partial) {
-		c->page = c->partial;
-		c->partial = c->page->next;
+		page = c->page = c->partial;
+		c->partial = page->next;
 		stat(s, CPU_PARTIAL_ALLOC);
 		c->freelist = NULL;
 		goto redo;
@@ -2256,14 +2258,15 @@ new_slab:
 		return NULL;
 	}
 
+	page = c->page;
 	if (likely(!kmem_cache_debug(s)))
 		goto load_freelist;
 
 	/* Only entered in the debug case */
-	if (!alloc_debug_processing(s, c->page, freelist, addr))
+	if (!alloc_debug_processing(s, page, freelist, addr))
 		goto new_slab;	/* Slab failed checks. Next slab needed */
 
-	deactivate_slab(s, c->page, get_freepointer(s, freelist));
+	deactivate_slab(s, page, get_freepointer(s, freelist));
 	c->page = NULL;
 	c->freelist = NULL;
 	local_irq_restore(flags);

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>