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authorChristoph Lameter2010-12-08 16:22:55 +0100
committerTejun Heo2010-12-17 15:07:19 +0100
commit909ea96468096b07fbb41aaf69be060d92bd9271 (patch)
treea7e015edd96b5f674874fe78cdd889769e130a2a /mm
parent780f36d8b3fa9572f731d4fb85067b2e45e6f993 (diff)
core: Replace __get_cpu_var with __this_cpu_read if not used for an address.
__get_cpu_var() can be replaced with this_cpu_read and will then use a single read instruction with implied address calculation to access the correct per cpu instance. However, the address of a per cpu variable passed to __this_cpu_read() cannot be determined (since it's an implied address conversion through segment prefixes). Therefore apply this only to uses of __get_cpu_var where the address of the variable is not used. Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Hugh Dickins <hughd@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slab.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/slab.c b/mm/slab.c
index b1e40dafbab3..316d75596f3c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -829,12 +829,12 @@ static void init_reap_node(int cpu)
static void next_reap_node(void)
{
- int node = __get_cpu_var(slab_reap_node);
+ int node = __this_cpu_read(slab_reap_node);
node = next_node(node, node_online_map);
if (unlikely(node >= MAX_NUMNODES))
node = first_node(node_online_map);
- __get_cpu_var(slab_reap_node) = node;
+ __this_cpu_write(slab_reap_node, node);
}
#else
@@ -1012,7 +1012,7 @@ static void __drain_alien_cache(struct kmem_cache *cachep,
*/
static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
{
- int node = __get_cpu_var(slab_reap_node);
+ int node = __this_cpu_read(slab_reap_node);
if (l3->alien) {
struct array_cache *ac = l3->alien[node];