[PATCH] slab: make drain_array more universal by adding more parameters

And a parameter to drain_array to control the freeing of all objects and
then use drain_array() to replace instances of drain_array_locked with
drain_array.  Doing so will avoid taking locks in those locations if the
arrays are empty.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 11 insertions, 9 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 1845c0127394..d73b38e7d7e8 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2126,6 +2126,10 @@ static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
 static void drain_array_locked(struct kmem_cache *cachep,
                         struct array_cache *ac, int force, int node);
 
+static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
+                        struct array_cache *ac,
+                        int force, int node);
+
 static void do_drain(void *arg)
 {
         struct kmem_cache *cachep = arg;
@@ -2150,9 +2154,7 @@ static void drain_cpu_caches(struct kmem_cache *cachep)
         for_each_online_node(node) {
                 l3 = cachep->nodelists[node];
                 if (l3) {
-                        spin_lock_irq(&l3->list_lock);
-                        drain_array_locked(cachep, l3->shared, 1, node);
-                        spin_unlock_irq(&l3->list_lock);
+                        drain_array(cachep, l3, l3->shared, 1, node);
                         if (l3->alien)
                                 drain_alien_cache(cachep, l3->alien);
                 }
@@ -3545,12 +3547,11 @@ static void drain_array_locked(struct kmem_cache *cachep,
  * necessary.
  */
 static void drain_array(struct kmem_cache *searchp, struct kmem_list3 *l3,
-                                         struct array_cache *ac)
+                         struct array_cache *ac, int force, int node)
 {
         if (ac && ac->avail) {
                 spin_lock_irq(&l3->list_lock);
-                drain_array_locked(searchp, ac, 0,
-                                   numa_node_id());
+                drain_array_locked(searchp, ac, force, node);
                 spin_unlock_irq(&l3->list_lock);
         }
 }
@@ -3571,6 +3572,7 @@ static void cache_reap(void *unused)
 {
         struct list_head *walk;
         struct kmem_list3 *l3;
+        int node = numa_node_id();
 
         if (!mutex_trylock(&cache_chain_mutex)) {
                 /* Give up. Setup the next iteration. */
@@ -3593,11 +3595,11 @@ static void cache_reap(void *unused)
                  * have established with reasonable certainty that
                  * we can do some work if the lock was obtained.
                  */
-                l3 = searchp->nodelists[numa_node_id()];
+                l3 = searchp->nodelists[node];
 
                 reap_alien(searchp, l3);
 
-                drain_array(searchp, l3, cpu_cache_get(searchp));
+                drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
 
                 /*
                  * These are racy checks but it does not matter
@@ -3608,7 +3610,7 @@ static void cache_reap(void *unused)
 
                 l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
 
-                drain_array(searchp, l3, l3->shared);
+                drain_array(searchp, l3, l3->shared, 0, node);
 
                 if (l3->free_touched) {
                         l3->free_touched = 0;