slab: introduce alien_cache
Currently, we use array_cache for alien_cache. Although they are mostly
similar, there is one difference, that is, need for spinlock. We don't
need spinlock for array_cache itself, but to use array_cache for
alien_cache, array_cache structure should have spinlock. This is
needless overhead, so removing it would be better. This patch prepare
it by introducing alien_cache and using it. In the following patch, we
remove spinlock in array_cache.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/slab.h b/mm/slab.h
index 3822b65..928823e 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -276,7 +276,7 @@
unsigned int free_limit;
unsigned int colour_next; /* Per-node cache coloring */
struct array_cache *shared; /* shared per node */
- struct array_cache **alien; /* on other nodes */
+ struct alien_cache **alien; /* on other nodes */
unsigned long next_reap; /* updated without locking */
int free_touched; /* updated without locking */
#endif