unsigned long next_reap;
int free_touched;
unsigned int free_limit;
+ unsigned int colour_next; /* Per-node cache coloring */
spinlock_t list_lock;
struct array_cache *shared; /* shared per node */
struct array_cache **alien; /* on other nodes */
INIT_LIST_HEAD(&parent->slabs_free);
parent->shared = NULL;
parent->alien = NULL;
+ parent->colour_next = 0;
spin_lock_init(&parent->list_lock);
parent->free_objects = 0;
parent->free_touched = 0;
size_t colour; /* cache colouring range */
unsigned int colour_off; /* colour offset */
- unsigned int colour_next; /* cache colouring */
struct kmem_cache *slabp_cache;
unsigned int slab_size;
unsigned int dflags; /* dynamic flags */
}
}
-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);
}
}
#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 struct array_cache **alloc_alien_cache(int node, int limit)
+{
+ return (struct array_cache **) 0x01020304ul;
+}
+
+static inline void free_alien_cache(struct array_cache **ac_ptr)
+{
+}
+
#endif
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;
}
& 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;
+
+ alien = alloc_alien_cache(node, cachep->limit);
+ if (!alien)
+ goto bad;
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;
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_irq(&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(&l3->list_lock);
+ spin_lock_irq(&l3->list_lock);
/* Free limit for this kmem_list3 */
l3->free_limit -= cachep->batchcount;
free_block(cachep, nc->entry, nc->avail, node);
if (!cpus_empty(mask)) {
- spin_unlock(&l3->list_lock);
- goto unlock_cache;
+ spin_unlock_irq(&l3->list_lock);
+ 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(&l3->list_lock);
- kfree(l3);
- } else {
- spin_unlock(&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_irq(&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
BUG();
cache_cache.colour = left_over / cache_cache.colour_off;
- cache_cache.colour_next = 0;
cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
sizeof(struct slab), cache_line_size());
BUG();
}
+ /*
+ * Prevent CPUs from coming and going.
+ * lock_cpu_hotplug() nests outside cache_chain_mutex
+ */
+ lock_cpu_hotplug();
+
mutex_lock(&cache_chain_mutex);
list_for_each(p, &cache_chain) {
cachep->dtor = dtor;
cachep->name = name;
- /* Don't let CPUs to come and go */
- lock_cpu_hotplug();
if (g_cpucache_up == FULL) {
enable_cpucache(cachep);
/* cache setup completed, link it into the list */
list_add(&cachep->next, &cache_chain);
- unlock_cpu_hotplug();
oops:
if (!cachep && (flags & SLAB_PANIC))
panic("kmem_cache_create(): failed to create slab `%s'\n",
name);
mutex_unlock(&cache_chain_mutex);
+ unlock_cpu_hotplug();
return cachep;
}
EXPORT_SYMBOL(kmem_cache_create);
smp_call_function_all_cpus(do_drain, cachep);
check_irq_on();
- spin_lock_irq(&cachep->spinlock);
for_each_online_node(node) {
l3 = cachep->nodelists[node];
if (l3) {
- spin_lock(&l3->list_lock);
+ spin_lock_irq(&l3->list_lock);
drain_array_locked(cachep, l3->shared, 1, node);
- spin_unlock(&l3->list_lock);
+ spin_unlock_irq(&l3->list_lock);
if (l3->alien)
- drain_alien_cache(cachep, l3);
+ drain_alien_cache(cachep, l3->alien);
}
}
- spin_unlock_irq(&cachep->spinlock);
}
static int __node_shrink(struct kmem_cache *cachep, int node)
*/
ctor_flags |= SLAB_CTOR_ATOMIC;
- /* About to mess with non-constant members - lock. */
+ /* Take the l3 list lock to change the colour_next on this node */
check_irq_off();
- spin_lock(&cachep->spinlock);
+ l3 = cachep->nodelists[nodeid];
+ spin_lock(&l3->list_lock);
/* Get colour for the slab, and cal the next value. */
- offset = cachep->colour_next;
- cachep->colour_next++;
- if (cachep->colour_next >= cachep->colour)
- cachep->colour_next = 0;
- offset *= cachep->colour_off;
+ offset = l3->colour_next;
+ l3->colour_next++;
+ if (l3->colour_next >= cachep->colour)
+ l3->colour_next = 0;
+ spin_unlock(&l3->list_lock);
- spin_unlock(&cachep->spinlock);
+ offset *= cachep->colour_off;
- check_irq_off();
if (local_flags & __GFP_WAIT)
local_irq_enable();
if (local_flags & __GFP_WAIT)
local_irq_disable();
check_irq_off();
- l3 = cachep->nodelists[nodeid];
spin_lock(&l3->list_lock);
/* Make slab active. */
BUG_ON(!l3);
retry:
+ check_irq_off();
spin_lock(&l3->list_lock);
entry = l3->slabs_partial.next;
if (entry == &l3->slabs_partial) {
smp_call_function_all_cpus(do_ccupdate_local, (void *)&new);
check_irq_on();
- spin_lock_irq(&cachep->spinlock);
+ spin_lock(&cachep->spinlock);
cachep->batchcount = batchcount;
cachep->limit = limit;
cachep->shared = shared;
- spin_unlock_irq(&cachep->spinlock);
+ spin_unlock(&cachep->spinlock);
for_each_online_cpu(i) {
struct array_cache *ccold = new.new[i];
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,
int node;
struct kmem_list3 *l3;
- check_irq_on();
- spin_lock_irq(&cachep->spinlock);
+ spin_lock(&cachep->spinlock);
active_objs = 0;
num_slabs = 0;
for_each_online_node(node) {
if (!l3)
continue;
- spin_lock(&l3->list_lock);
+ check_irq_on();
+ spin_lock_irq(&l3->list_lock);
list_for_each(q, &l3->slabs_full) {
slabp = list_entry(q, struct slab, list);
num_slabs++;
}
free_objects += l3->free_objects;
- shared_avail += l3->shared->avail;
+ if (l3->shared)
+ shared_avail += l3->shared->avail;
- spin_unlock(&l3->list_lock);
+ spin_unlock_irq(&l3->list_lock);
}
num_slabs += active_slabs;
num_objs = num_slabs * cachep->num;
}
#endif
seq_putc(m, '\n');
- spin_unlock_irq(&cachep->spinlock);
+ spin_unlock(&cachep->spinlock);
return 0;
}