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-rw-r--r--mm/slab.c123
1 files changed, 85 insertions, 38 deletions
diff --git a/mm/slab.c b/mm/slab.c
index d3f68543f9f..9cc049a942c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -884,14 +884,14 @@ static void __drain_alien_cache(struct kmem_cache *cachep,
}
}
-static void drain_alien_cache(struct kmem_cache *cachep, struct kmem_list3 *l3)
+static void drain_alien_cache(struct kmem_cache *cachep, struct array_cache **alien)
{
int i = 0;
struct array_cache *ac;
unsigned long flags;
for_each_online_node(i) {
- ac = l3->alien[i];
+ ac = alien[i];
if (ac) {
spin_lock_irqsave(&ac->lock, flags);
__drain_alien_cache(cachep, ac, i);
@@ -901,8 +901,11 @@ static void drain_alien_cache(struct kmem_cache *cachep, struct kmem_list3 *l3)
}
#else
#define alloc_alien_cache(node, limit) do { } while (0)
-#define free_alien_cache(ac_ptr) do { } while (0)
-#define drain_alien_cache(cachep, l3) do { } while (0)
+#define drain_alien_cache(cachep, alien) do { } while (0)
+
+static inline void free_alien_cache(struct array_cache **ac_ptr)
+{
+}
#endif
static int __devinit cpuup_callback(struct notifier_block *nfb,
@@ -936,6 +939,11 @@ static int __devinit cpuup_callback(struct notifier_block *nfb,
l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
((unsigned long)cachep) % REAPTIMEOUT_LIST3;
+ /*
+ * The l3s don't come and go as CPUs come and
+ * go. cache_chain_mutex is sufficient
+ * protection here.
+ */
cachep->nodelists[node] = l3;
}
@@ -950,26 +958,47 @@ static int __devinit cpuup_callback(struct notifier_block *nfb,
& array cache's */
list_for_each_entry(cachep, &cache_chain, next) {
struct array_cache *nc;
+ struct array_cache *shared;
+ struct array_cache **alien;
nc = alloc_arraycache(node, cachep->limit,
- cachep->batchcount);
+ cachep->batchcount);
if (!nc)
goto bad;
+ shared = alloc_arraycache(node,
+ cachep->shared * cachep->batchcount,
+ 0xbaadf00d);
+ if (!shared)
+ goto bad;
+#ifdef CONFIG_NUMA
+ alien = alloc_alien_cache(node, cachep->limit);
+ if (!alien)
+ goto bad;
+#endif
cachep->array[cpu] = nc;
l3 = cachep->nodelists[node];
BUG_ON(!l3);
- if (!l3->shared) {
- if (!(nc = alloc_arraycache(node,
- cachep->shared *
- cachep->batchcount,
- 0xbaadf00d)))
- goto bad;
- /* we are serialised from CPU_DEAD or
- CPU_UP_CANCELLED by the cpucontrol lock */
- l3->shared = nc;
+ spin_lock_irq(&l3->list_lock);
+ if (!l3->shared) {
+ /*
+ * We are serialised from CPU_DEAD or
+ * CPU_UP_CANCELLED by the cpucontrol lock
+ */
+ l3->shared = shared;
+ shared = NULL;
}
+#ifdef CONFIG_NUMA
+ if (!l3->alien) {
+ l3->alien = alien;
+ alien = NULL;
+ }
+#endif
+ spin_unlock_irq(&l3->list_lock);
+
+ kfree(shared);
+ free_alien_cache(alien);
}
mutex_unlock(&cache_chain_mutex);
break;
@@ -978,23 +1007,32 @@ static int __devinit cpuup_callback(struct notifier_block *nfb,
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_DEAD:
+ /*
+ * Even if all the cpus of a node are down, we don't free the
+ * kmem_list3 of any cache. This to avoid a race between
+ * cpu_down, and a kmalloc allocation from another cpu for
+ * memory from the node of the cpu going down. The list3
+ * structure is usually allocated from kmem_cache_create() and
+ * gets destroyed at kmem_cache_destroy().
+ */
/* fall thru */
case CPU_UP_CANCELED:
mutex_lock(&cache_chain_mutex);
list_for_each_entry(cachep, &cache_chain, next) {
struct array_cache *nc;
+ struct array_cache *shared;
+ struct array_cache **alien;
cpumask_t mask;
mask = node_to_cpumask(node);
- spin_lock(&cachep->spinlock);
/* cpu is dead; no one can alloc from it. */
nc = cachep->array[cpu];
cachep->array[cpu] = NULL;
l3 = cachep->nodelists[node];
if (!l3)
- goto unlock_cache;
+ goto free_array_cache;
spin_lock_irq(&l3->list_lock);
@@ -1005,33 +1043,43 @@ static int __devinit cpuup_callback(struct notifier_block *nfb,
if (!cpus_empty(mask)) {
spin_unlock_irq(&l3->list_lock);
- goto unlock_cache;
+ goto free_array_cache;
}
- if (l3->shared) {
+ shared = l3->shared;
+ if (shared) {
free_block(cachep, l3->shared->entry,
l3->shared->avail, node);
- kfree(l3->shared);
l3->shared = NULL;
}
- if (l3->alien) {
- drain_alien_cache(cachep, l3);
- free_alien_cache(l3->alien);
- l3->alien = NULL;
- }
- /* free slabs belonging to this node */
- if (__node_shrink(cachep, node)) {
- cachep->nodelists[node] = NULL;
- spin_unlock_irq(&l3->list_lock);
- kfree(l3);
- } else {
- spin_unlock_irq(&l3->list_lock);
+ alien = l3->alien;
+ l3->alien = NULL;
+
+ spin_unlock_irq(&l3->list_lock);
+
+ kfree(shared);
+ if (alien) {
+ drain_alien_cache(cachep, alien);
+ free_alien_cache(alien);
}
- unlock_cache:
- spin_unlock(&cachep->spinlock);
+free_array_cache:
kfree(nc);
}
+ /*
+ * In the previous loop, all the objects were freed to
+ * the respective cache's slabs, now we can go ahead and
+ * shrink each nodelist to its limit.
+ */
+ list_for_each_entry(cachep, &cache_chain, next) {
+ l3 = cachep->nodelists[node];
+ if (!l3)
+ continue;
+ spin_lock_irq(&l3->list_lock);
+ /* free slabs belonging to this node */
+ __node_shrink(cachep, node);
+ spin_unlock_irq(&l3->list_lock);
+ }
mutex_unlock(&cache_chain_mutex);
break;
#endif
@@ -2011,7 +2059,6 @@ static void drain_cpu_caches(struct kmem_cache *cachep)
smp_call_function_all_cpus(do_drain, cachep);
check_irq_on();
- spin_lock(&cachep->spinlock);
for_each_online_node(node) {
l3 = cachep->nodelists[node];
if (l3) {
@@ -2019,10 +2066,9 @@ static void drain_cpu_caches(struct kmem_cache *cachep)
drain_array_locked(cachep, l3->shared, 1, node);
spin_unlock_irq(&l3->list_lock);
if (l3->alien)
- drain_alien_cache(cachep, l3);
+ drain_alien_cache(cachep, l3->alien);
}
}
- spin_unlock(&cachep->spinlock);
}
static int __node_shrink(struct kmem_cache *cachep, int node)
@@ -3440,7 +3486,7 @@ static void cache_reap(void *unused)
l3 = searchp->nodelists[numa_node_id()];
if (l3->alien)
- drain_alien_cache(searchp, l3);
+ drain_alien_cache(searchp, l3->alien);
spin_lock_irq(&l3->list_lock);
drain_array_locked(searchp, cpu_cache_get(searchp), 0,
@@ -3598,7 +3644,8 @@ static int s_show(struct seq_file *m, void *p)
num_slabs++;
}
free_objects += l3->free_objects;
- shared_avail += l3->shared->avail;
+ if (l3->shared)
+ shared_avail += l3->shared->avail;
spin_unlock_irq(&l3->list_lock);
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-22 19:03:29 +0000