.name = "kmem_cache",
};
-#define BAD_ALIEN_MAGIC 0x01020304ul
-
static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
static inline struct alien_cache **alloc_alien_cache(int node,
int limit, gfp_t gfp)
{
- return (struct alien_cache **)BAD_ALIEN_MAGIC;
+ return NULL;
}
static inline void free_alien_cache(struct alien_cache **ac_ptr)
}
#endif
+static int init_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp)
+{
+ struct kmem_cache_node *n;
+
+ /*
+ * Set up the kmem_cache_node for cpu before we can
+ * begin anything. Make sure some other cpu on this
+ * node has not already allocated this
+ */
+ n = get_node(cachep, node);
+ if (n) {
+ spin_lock_irq(&n->list_lock);
+ n->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount +
+ cachep->num;
+ spin_unlock_irq(&n->list_lock);
+
+ return 0;
+ }
+
+ n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node);
+ if (!n)
+ return -ENOMEM;
+
+ kmem_cache_node_init(n);
+ n->next_reap = jiffies + REAPTIMEOUT_NODE +
+ ((unsigned long)cachep) % REAPTIMEOUT_NODE;
+
+ n->free_limit =
+ (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num;
+
+ /*
+ * The kmem_cache_nodes don't come and go as CPUs
+ * come and go. slab_mutex is sufficient
+ * protection here.
+ */
+ cachep->node[node] = n;
+
+ return 0;
+}
+
/*
* Allocates and initializes node for a node on each slab cache, used for
* either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node
*/
static int init_cache_node_node(int node)
{
+ int ret;
struct kmem_cache *cachep;
- struct kmem_cache_node *n;
- const size_t memsize = sizeof(struct kmem_cache_node);
list_for_each_entry(cachep, &slab_caches, list) {
- /*
- * Set up the kmem_cache_node for cpu before we can
- * begin anything. Make sure some other cpu on this
- * node has not already allocated this
- */
- n = get_node(cachep, node);
- if (!n) {
- n = kmalloc_node(memsize, GFP_KERNEL, node);
- if (!n)
- return -ENOMEM;
- kmem_cache_node_init(n);
- n->next_reap = jiffies + REAPTIMEOUT_NODE +
- ((unsigned long)cachep) % REAPTIMEOUT_NODE;
-
- /*
- * The kmem_cache_nodes don't come and go as CPUs
- * come and go. slab_mutex is sufficient
- * protection here.
- */
- cachep->node[node] = n;
- }
-
- spin_lock_irq(&n->list_lock);
- n->free_limit =
- (1 + nr_cpus_node(node)) *
- cachep->batchcount + cachep->num;
- spin_unlock_irq(&n->list_lock);
+ ret = init_cache_node(cachep, node, GFP_KERNEL);
+ if (ret)
+ return ret;
}
+
return 0;
}
-static inline int slabs_tofree(struct kmem_cache *cachep,
- struct kmem_cache_node *n)
+static int setup_kmem_cache_node(struct kmem_cache *cachep,
+ int node, gfp_t gfp, bool force_change)
{
- return (n->free_objects + cachep->num - 1) / cachep->num;
+ int ret = -ENOMEM;
+ struct kmem_cache_node *n;
+ struct array_cache *old_shared = NULL;
+ struct array_cache *new_shared = NULL;
+ struct alien_cache **new_alien = NULL;
+ LIST_HEAD(list);
+
+ if (use_alien_caches) {
+ new_alien = alloc_alien_cache(node, cachep->limit, gfp);
+ if (!new_alien)
+ goto fail;
+ }
+
+ if (cachep->shared) {
+ new_shared = alloc_arraycache(node,
+ cachep->shared * cachep->batchcount, 0xbaadf00d, gfp);
+ if (!new_shared)
+ goto fail;
+ }
+
+ ret = init_cache_node(cachep, node, gfp);
+ if (ret)
+ goto fail;
+
+ n = get_node(cachep, node);
+ spin_lock_irq(&n->list_lock);
+ if (n->shared && force_change) {
+ free_block(cachep, n->shared->entry,
+ n->shared->avail, node, &list);
+ n->shared->avail = 0;
+ }
+
+ if (!n->shared || force_change) {
+ old_shared = n->shared;
+ n->shared = new_shared;
+ new_shared = NULL;
+ }
+
+ if (!n->alien) {
+ n->alien = new_alien;
+ new_alien = NULL;
+ }
+
+ spin_unlock_irq(&n->list_lock);
+ slabs_destroy(cachep, &list);
+
+fail:
+ kfree(old_shared);
+ kfree(new_shared);
+ free_alien_cache(new_alien);
+
+ return ret;
}
static void cpuup_canceled(long cpu)
n = get_node(cachep, node);
if (!n)
continue;
- drain_freelist(cachep, n, slabs_tofree(cachep, n));
+ drain_freelist(cachep, n, INT_MAX);
}
}
static int cpuup_prepare(long cpu)
{
struct kmem_cache *cachep;
- struct kmem_cache_node *n = NULL;
int node = cpu_to_mem(cpu);
int err;
* array caches
*/
list_for_each_entry(cachep, &slab_caches, list) {
- struct array_cache *shared = NULL;
- struct alien_cache **alien = NULL;
-
- if (cachep->shared) {
- shared = alloc_arraycache(node,
- cachep->shared * cachep->batchcount,
- 0xbaadf00d, GFP_KERNEL);
- if (!shared)
- goto bad;
- }
- if (use_alien_caches) {
- alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL);
- if (!alien) {
- kfree(shared);
- goto bad;
- }
- }
- n = get_node(cachep, node);
- BUG_ON(!n);
-
- spin_lock_irq(&n->list_lock);
- if (!n->shared) {
- /*
- * We are serialised from CPU_DEAD or
- * CPU_UP_CANCELLED by the cpucontrol lock
- */
- n->shared = shared;
- shared = NULL;
- }
-#ifdef CONFIG_NUMA
- if (!n->alien) {
- n->alien = alien;
- alien = NULL;
- }
-#endif
- spin_unlock_irq(&n->list_lock);
- kfree(shared);
- free_alien_cache(alien);
+ err = setup_kmem_cache_node(cachep, node, GFP_KERNEL, false);
+ if (err)
+ goto bad;
}
return 0;
if (!n)
continue;
- drain_freelist(cachep, n, slabs_tofree(cachep, n));
+ drain_freelist(cachep, n, INT_MAX);
if (!list_empty(&n->slabs_full) ||
!list_empty(&n->slabs_partial)) {
sizeof(struct rcu_head));
kmem_cache = &kmem_cache_boot;
- if (num_possible_nodes() == 1)
+ if (!IS_ENABLED(CONFIG_NUMA) || num_possible_nodes() == 1)
use_alien_caches = 0;
for (i = 0; i < NUM_INIT_LISTS; i++)
BUG_ON(irqs_disabled());
}
+static void check_mutex_acquired(void)
+{
+ BUG_ON(!mutex_is_locked(&slab_mutex));
+}
+
static void check_spinlock_acquired(struct kmem_cache *cachep)
{
#ifdef CONFIG_SMP
#else
#define check_irq_off() do { } while(0)
#define check_irq_on() do { } while(0)
+#define check_mutex_acquired() do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
#define check_spinlock_acquired_node(x, y) do { } while(0)
#endif
-static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n,
- struct array_cache *ac,
- int force, int node);
+static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac,
+ int node, bool free_all, struct list_head *list)
+{
+ int tofree;
+
+ if (!ac || !ac->avail)
+ return;
+
+ tofree = free_all ? ac->avail : (ac->limit + 4) / 5;
+ if (tofree > ac->avail)
+ tofree = (ac->avail + 1) / 2;
+
+ free_block(cachep, ac->entry, tofree, node, list);
+ ac->avail -= tofree;
+ memmove(ac->entry, &(ac->entry[tofree]), sizeof(void *) * ac->avail);
+}
static void do_drain(void *arg)
{
{
struct kmem_cache_node *n;
int node;
+ LIST_HEAD(list);
on_each_cpu(do_drain, cachep, 1);
check_irq_on();
if (n->alien)
drain_alien_cache(cachep, n->alien);
- for_each_kmem_cache_node(cachep, node, n)
- drain_array(cachep, n, n->shared, 1, node);
+ for_each_kmem_cache_node(cachep, node, n) {
+ spin_lock_irq(&n->list_lock);
+ drain_array_locked(cachep, n->shared, node, true, &list);
+ spin_unlock_irq(&n->list_lock);
+
+ slabs_destroy(cachep, &list);
+ }
}
/*
check_irq_on();
for_each_kmem_cache_node(cachep, node, n) {
- drain_freelist(cachep, n, slabs_tofree(cachep, n));
+ drain_freelist(cachep, n, INT_MAX);
ret += !list_empty(&n->slabs_full) ||
!list_empty(&n->slabs_partial);
/*
* This initializes kmem_cache_node or resizes various caches for all nodes.
*/
-static int alloc_kmem_cache_node(struct kmem_cache *cachep, gfp_t gfp)
+static int setup_kmem_cache_nodes(struct kmem_cache *cachep, gfp_t gfp)
{
+ int ret;
int node;
struct kmem_cache_node *n;
- struct array_cache *new_shared;
- struct alien_cache **new_alien = NULL;
for_each_online_node(node) {
-
- if (use_alien_caches) {
- new_alien = alloc_alien_cache(node, cachep->limit, gfp);
- if (!new_alien)
- goto fail;
- }
-
- new_shared = NULL;
- if (cachep->shared) {
- new_shared = alloc_arraycache(node,
- cachep->shared*cachep->batchcount,
- 0xbaadf00d, gfp);
- if (!new_shared) {
- free_alien_cache(new_alien);
- goto fail;
- }
- }
-
- n = get_node(cachep, node);
- if (n) {
- struct array_cache *shared = n->shared;
- LIST_HEAD(list);
-
- spin_lock_irq(&n->list_lock);
-
- if (shared)
- free_block(cachep, shared->entry,
- shared->avail, node, &list);
-
- n->shared = new_shared;
- if (!n->alien) {
- n->alien = new_alien;
- new_alien = NULL;
- }
- n->free_limit = (1 + nr_cpus_node(node)) *
- cachep->batchcount + cachep->num;
- spin_unlock_irq(&n->list_lock);
- slabs_destroy(cachep, &list);
- kfree(shared);
- free_alien_cache(new_alien);
- continue;
- }
- n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node);
- if (!n) {
- free_alien_cache(new_alien);
- kfree(new_shared);
+ ret = setup_kmem_cache_node(cachep, node, gfp, true);
+ if (ret)
goto fail;
- }
- kmem_cache_node_init(n);
- n->next_reap = jiffies + REAPTIMEOUT_NODE +
- ((unsigned long)cachep) % REAPTIMEOUT_NODE;
- n->shared = new_shared;
- n->alien = new_alien;
- n->free_limit = (1 + nr_cpus_node(node)) *
- cachep->batchcount + cachep->num;
- cachep->node[node] = n;
}
+
return 0;
fail:
cachep->shared = shared;
if (!prev)
- goto alloc_node;
+ goto setup_node;
for_each_online_cpu(cpu) {
LIST_HEAD(list);
}
free_percpu(prev);
-alloc_node:
- return alloc_kmem_cache_node(cachep, gfp);
+setup_node:
+ return setup_kmem_cache_nodes(cachep, gfp);
}
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
* if drain_array() is used on the shared array.
*/
static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n,
- struct array_cache *ac, int force, int node)
+ struct array_cache *ac, int node)
{
LIST_HEAD(list);
- int tofree;
+
+ /* ac from n->shared can be freed if we don't hold the slab_mutex. */
+ check_mutex_acquired();
if (!ac || !ac->avail)
return;
- if (ac->touched && !force) {
+
+ if (ac->touched) {
ac->touched = 0;
- } else {
- spin_lock_irq(&n->list_lock);
- if (ac->avail) {
- tofree = force ? ac->avail : (ac->limit + 4) / 5;
- if (tofree > ac->avail)
- tofree = (ac->avail + 1) / 2;
- free_block(cachep, ac->entry, tofree, node, &list);
- ac->avail -= tofree;
- memmove(ac->entry, &(ac->entry[tofree]),
- sizeof(void *) * ac->avail);
- }
- spin_unlock_irq(&n->list_lock);
- slabs_destroy(cachep, &list);
+ return;
}
+
+ spin_lock_irq(&n->list_lock);
+ drain_array_locked(cachep, ac, node, false, &list);
+ spin_unlock_irq(&n->list_lock);
+
+ slabs_destroy(cachep, &list);
}
/**
reap_alien(searchp, n);
- drain_array(searchp, n, cpu_cache_get(searchp), 0, node);
+ drain_array(searchp, n, cpu_cache_get(searchp), node);
/*
* These are racy checks but it does not matter
n->next_reap = jiffies + REAPTIMEOUT_NODE;
- drain_array(searchp, n, n->shared, 0, node);
+ drain_array(searchp, n, n->shared, node);
if (n->free_touched)
n->free_touched = 0;