[patch] slab: resize the alien caches too

["Siddha, Suresh B" <suresh.b.siddha@intel.com>]

Christoph,

While going through the slab code, I observed that alien caches are
not getting resized, when user changes the slab tunables. Appended patch
tries to fix this. Please review and let me know if I missed anything.

thanks,
suresh
---

Resize the alien caches too based on the slab tunables.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
---

diff --git a/mm/slab.c b/mm/slab.c
index 4cbac24..e0dd9af 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3823,6 +3823,7 @@ static int alloc_kmemlist(struct kmem_cache *cachep)
 		l3 = cachep->nodelists[node];
 		if (l3) {
 			struct array_cache *shared = l3->shared;
+			struct array_cache **alien = l3->alien;
 
 			spin_lock_irq(&l3->list_lock);
 
@@ -3831,15 +3832,15 @@ static int alloc_kmemlist(struct kmem_cache *cachep)
 						shared->avail, node);
 
 			l3->shared = new_shared;
-			if (!l3->alien) {
-				l3->alien = new_alien;
-				new_alien = NULL;
-			}
+			l3->alien = new_alien;
 			l3->free_limit = (1 + nr_cpus_node(node)) *
 					cachep->batchcount + cachep->num;
 			spin_unlock_irq(&l3->list_lock);
 			kfree(shared);
-			free_alien_cache(new_alien);
+			if (alien) {
+				drain_alien_cache(cachep, alien);
+				free_alien_cache(alien);
+			}
 			continue;
 		}
 		l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);