#include <linux/mutex.h>
#include <linux/memcontrol.h>
#include "slab.h"
+#include "internal.h"
#ifdef CONFIG_MEMCG_KMEM
static LIST_HEAD(memcg_list_lrus);
}
static inline struct list_lru_one *
-list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
+list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx)
{
- struct list_lru_memcg *memcg_lrus;
- /*
- * Either lock or RCU protects the array of per cgroup lists
- * from relocation (see memcg_update_list_lru_node).
- */
- memcg_lrus = rcu_dereference_check(nlru->memcg_lrus,
- lockdep_is_held(&nlru->lock));
- if (memcg_lrus && idx >= 0)
- return memcg_lrus->lru[idx];
- return &nlru->lru;
+ if (list_lru_memcg_aware(lru) && idx >= 0) {
+ struct list_lru_memcg *mlru = xa_load(&lru->xa, idx);
+
+ return mlru ? &mlru->node[nid] : NULL;
+ }
+ return &lru->node[nid].lru;
}
static inline struct list_lru_one *
-list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
+list_lru_from_kmem(struct list_lru *lru, int nid, void *ptr,
struct mem_cgroup **memcg_ptr)
{
+ struct list_lru_node *nlru = &lru->node[nid];
struct list_lru_one *l = &nlru->lru;
struct mem_cgroup *memcg = NULL;
- if (!nlru->memcg_lrus)
+ if (!list_lru_memcg_aware(lru))
goto out;
memcg = mem_cgroup_from_obj(ptr);
if (!memcg)
goto out;
- l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
+ l = list_lru_from_memcg_idx(lru, nid, memcg_kmem_id(memcg));
out:
if (memcg_ptr)
*memcg_ptr = memcg;
}
static inline struct list_lru_one *
-list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
+list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx)
{
- return &nlru->lru;
+ return &lru->node[nid].lru;
}
static inline struct list_lru_one *
-list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
+list_lru_from_kmem(struct list_lru *lru, int nid, void *ptr,
struct mem_cgroup **memcg_ptr)
{
if (memcg_ptr)
*memcg_ptr = NULL;
- return &nlru->lru;
+ return &lru->node[nid].lru;
}
#endif /* CONFIG_MEMCG_KMEM */
spin_lock(&nlru->lock);
if (list_empty(item)) {
- l = list_lru_from_kmem(nlru, item, &memcg);
+ l = list_lru_from_kmem(lru, nid, item, &memcg);
list_add_tail(item, &l->list);
/* Set shrinker bit if the first element was added */
if (!l->nr_items++)
spin_lock(&nlru->lock);
if (!list_empty(item)) {
- l = list_lru_from_kmem(nlru, item, NULL);
+ l = list_lru_from_kmem(lru, nid, item, NULL);
list_del_init(item);
l->nr_items--;
nlru->nr_items--;
unsigned long list_lru_count_one(struct list_lru *lru,
int nid, struct mem_cgroup *memcg)
{
- struct list_lru_node *nlru = &lru->node[nid];
struct list_lru_one *l;
long count;
rcu_read_lock();
- l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
- count = READ_ONCE(l->nr_items);
+ l = list_lru_from_memcg_idx(lru, nid, memcg_kmem_id(memcg));
+ count = l ? READ_ONCE(l->nr_items) : 0;
rcu_read_unlock();
if (unlikely(count < 0))
EXPORT_SYMBOL_GPL(list_lru_count_node);
static unsigned long
-__list_lru_walk_one(struct list_lru_node *nlru, int memcg_idx,
+__list_lru_walk_one(struct list_lru *lru, int nid, int memcg_idx,
list_lru_walk_cb isolate, void *cb_arg,
unsigned long *nr_to_walk)
{
-
+ struct list_lru_node *nlru = &lru->node[nid];
struct list_lru_one *l;
struct list_head *item, *n;
unsigned long isolated = 0;
- l = list_lru_from_memcg_idx(nlru, memcg_idx);
restart:
+ l = list_lru_from_memcg_idx(lru, nid, memcg_idx);
+ if (!l)
+ goto out;
+
list_for_each_safe(item, n, &l->list) {
enum lru_status ret;
BUG();
}
}
+out:
return isolated;
}
unsigned long ret;
spin_lock(&nlru->lock);
- ret = __list_lru_walk_one(nlru, memcg_cache_id(memcg), isolate, cb_arg,
- nr_to_walk);
+ ret = __list_lru_walk_one(lru, nid, memcg_kmem_id(memcg), isolate,
+ cb_arg, nr_to_walk);
spin_unlock(&nlru->lock);
return ret;
}
unsigned long ret;
spin_lock_irq(&nlru->lock);
- ret = __list_lru_walk_one(nlru, memcg_cache_id(memcg), isolate, cb_arg,
- nr_to_walk);
+ ret = __list_lru_walk_one(lru, nid, memcg_kmem_id(memcg), isolate,
+ cb_arg, nr_to_walk);
spin_unlock_irq(&nlru->lock);
return ret;
}
unsigned long *nr_to_walk)
{
long isolated = 0;
- int memcg_idx;
isolated += list_lru_walk_one(lru, nid, NULL, isolate, cb_arg,
nr_to_walk);
+
+#ifdef CONFIG_MEMCG_KMEM
if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
- for_each_memcg_cache_index(memcg_idx) {
+ struct list_lru_memcg *mlru;
+ unsigned long index;
+
+ xa_for_each(&lru->xa, index, mlru) {
struct list_lru_node *nlru = &lru->node[nid];
spin_lock(&nlru->lock);
- isolated += __list_lru_walk_one(nlru, memcg_idx,
+ isolated += __list_lru_walk_one(lru, nid, index,
isolate, cb_arg,
nr_to_walk);
spin_unlock(&nlru->lock);
break;
}
}
+#endif
+
return isolated;
}
EXPORT_SYMBOL_GPL(list_lru_walk_node);
}
#ifdef CONFIG_MEMCG_KMEM
-static void __memcg_destroy_list_lru_node(struct list_lru_memcg *memcg_lrus,
- int begin, int end)
+static struct list_lru_memcg *memcg_init_list_lru_one(gfp_t gfp)
{
- int i;
-
- for (i = begin; i < end; i++)
- kfree(memcg_lrus->lru[i]);
-}
-
-static int __memcg_init_list_lru_node(struct list_lru_memcg *memcg_lrus,
- int begin, int end)
-{
- int i;
+ int nid;
+ struct list_lru_memcg *mlru;
- for (i = begin; i < end; i++) {
- struct list_lru_one *l;
+ mlru = kmalloc(struct_size(mlru, node, nr_node_ids), gfp);
+ if (!mlru)
+ return NULL;
- l = kmalloc(sizeof(struct list_lru_one), GFP_KERNEL);
- if (!l)
- goto fail;
+ for_each_node(nid)
+ init_one_lru(&mlru->node[nid]);
- init_one_lru(l);
- memcg_lrus->lru[i] = l;
- }
- return 0;
-fail:
- __memcg_destroy_list_lru_node(memcg_lrus, begin, i);
- return -ENOMEM;
+ return mlru;
}
-static int memcg_init_list_lru_node(struct list_lru_node *nlru)
+static void memcg_list_lru_free(struct list_lru *lru, int src_idx)
{
- struct list_lru_memcg *memcg_lrus;
- int size = memcg_nr_cache_ids;
-
- memcg_lrus = kvmalloc(struct_size(memcg_lrus, lru, size), GFP_KERNEL);
- if (!memcg_lrus)
- return -ENOMEM;
-
- if (__memcg_init_list_lru_node(memcg_lrus, 0, size)) {
- kvfree(memcg_lrus);
- return -ENOMEM;
- }
- RCU_INIT_POINTER(nlru->memcg_lrus, memcg_lrus);
-
- return 0;
-}
+ struct list_lru_memcg *mlru = xa_erase_irq(&lru->xa, src_idx);
-static void memcg_destroy_list_lru_node(struct list_lru_node *nlru)
-{
- struct list_lru_memcg *memcg_lrus;
/*
- * This is called when shrinker has already been unregistered,
- * and nobody can use it. So, there is no need to use kvfree_rcu().
+ * The __list_lru_walk_one() can walk the list of this node.
+ * We need kvfree_rcu() here. And the walking of the list
+ * is under lru->node[nid]->lock, which can serve as a RCU
+ * read-side critical section.
*/
- memcg_lrus = rcu_dereference_protected(nlru->memcg_lrus, true);
- __memcg_destroy_list_lru_node(memcg_lrus, 0, memcg_nr_cache_ids);
- kvfree(memcg_lrus);
+ if (mlru)
+ kvfree_rcu(mlru, rcu);
}
-static int memcg_update_list_lru_node(struct list_lru_node *nlru,
- int old_size, int new_size)
+static inline void memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
{
- struct list_lru_memcg *old, *new;
-
- BUG_ON(old_size > new_size);
-
- old = rcu_dereference_protected(nlru->memcg_lrus,
- lockdep_is_held(&list_lrus_mutex));
- new = kvmalloc(struct_size(new, lru, new_size), GFP_KERNEL);
- if (!new)
- return -ENOMEM;
-
- if (__memcg_init_list_lru_node(new, old_size, new_size)) {
- kvfree(new);
- return -ENOMEM;
- }
-
- memcpy(&new->lru, &old->lru, flex_array_size(new, lru, old_size));
- rcu_assign_pointer(nlru->memcg_lrus, new);
- kvfree_rcu(old, rcu);
- return 0;
-}
-
-static void memcg_cancel_update_list_lru_node(struct list_lru_node *nlru,
- int old_size, int new_size)
-{
- struct list_lru_memcg *memcg_lrus;
-
- memcg_lrus = rcu_dereference_protected(nlru->memcg_lrus,
- lockdep_is_held(&list_lrus_mutex));
- /* do not bother shrinking the array back to the old size, because we
- * cannot handle allocation failures here */
- __memcg_destroy_list_lru_node(memcg_lrus, old_size, new_size);
-}
-
-static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
-{
- int i;
-
+ if (memcg_aware)
+ xa_init_flags(&lru->xa, XA_FLAGS_LOCK_IRQ);
lru->memcg_aware = memcg_aware;
-
- if (!memcg_aware)
- return 0;
-
- for_each_node(i) {
- if (memcg_init_list_lru_node(&lru->node[i]))
- goto fail;
- }
- return 0;
-fail:
- for (i = i - 1; i >= 0; i--) {
- if (!lru->node[i].memcg_lrus)
- continue;
- memcg_destroy_list_lru_node(&lru->node[i]);
- }
- return -ENOMEM;
}
static void memcg_destroy_list_lru(struct list_lru *lru)
{
- int i;
+ XA_STATE(xas, &lru->xa, 0);
+ struct list_lru_memcg *mlru;
if (!list_lru_memcg_aware(lru))
return;
- for_each_node(i)
- memcg_destroy_list_lru_node(&lru->node[i]);
-}
-
-static int memcg_update_list_lru(struct list_lru *lru,
- int old_size, int new_size)
-{
- int i;
-
- for_each_node(i) {
- if (memcg_update_list_lru_node(&lru->node[i],
- old_size, new_size))
- goto fail;
- }
- return 0;
-fail:
- for (i = i - 1; i >= 0; i--) {
- if (!lru->node[i].memcg_lrus)
- continue;
-
- memcg_cancel_update_list_lru_node(&lru->node[i],
- old_size, new_size);
+ xas_lock_irq(&xas);
+ xas_for_each(&xas, mlru, ULONG_MAX) {
+ kfree(mlru);
+ xas_store(&xas, NULL);
}
- return -ENOMEM;
-}
-
-static void memcg_cancel_update_list_lru(struct list_lru *lru,
- int old_size, int new_size)
-{
- int i;
-
- for_each_node(i)
- memcg_cancel_update_list_lru_node(&lru->node[i],
- old_size, new_size);
+ xas_unlock_irq(&xas);
}
-int memcg_update_all_list_lrus(int new_size)
-{
- int ret = 0;
- struct list_lru *lru;
- int old_size = memcg_nr_cache_ids;
-
- mutex_lock(&list_lrus_mutex);
- list_for_each_entry(lru, &memcg_list_lrus, list) {
- ret = memcg_update_list_lru(lru, old_size, new_size);
- if (ret)
- goto fail;
- }
-out:
- mutex_unlock(&list_lrus_mutex);
- return ret;
-fail:
- list_for_each_entry_continue_reverse(lru, &memcg_list_lrus, list)
- memcg_cancel_update_list_lru(lru, old_size, new_size);
- goto out;
-}
-
-static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
- int src_idx, struct mem_cgroup *dst_memcg)
+static void memcg_reparent_list_lru_node(struct list_lru *lru, int nid,
+ int src_idx, struct mem_cgroup *dst_memcg)
{
struct list_lru_node *nlru = &lru->node[nid];
int dst_idx = dst_memcg->kmemcg_id;
struct list_lru_one *src, *dst;
+ /*
+ * If there is no lru entry in this nlru, we can skip it immediately.
+ */
+ if (!READ_ONCE(nlru->nr_items))
+ return;
+
/*
* Since list_lru_{add,del} may be called under an IRQ-safe lock,
* we have to use IRQ-safe primitives here to avoid deadlock.
*/
spin_lock_irq(&nlru->lock);
- src = list_lru_from_memcg_idx(nlru, src_idx);
- dst = list_lru_from_memcg_idx(nlru, dst_idx);
+ src = list_lru_from_memcg_idx(lru, nid, src_idx);
+ if (!src)
+ goto out;
+ dst = list_lru_from_memcg_idx(lru, nid, dst_idx);
list_splice_init(&src->list, &dst->list);
set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru));
src->nr_items = 0;
}
-
+out:
spin_unlock_irq(&nlru->lock);
}
-static void memcg_drain_list_lru(struct list_lru *lru,
- int src_idx, struct mem_cgroup *dst_memcg)
+static void memcg_reparent_list_lru(struct list_lru *lru,
+ int src_idx, struct mem_cgroup *dst_memcg)
{
int i;
for_each_node(i)
- memcg_drain_list_lru_node(lru, i, src_idx, dst_memcg);
+ memcg_reparent_list_lru_node(lru, i, src_idx, dst_memcg);
+
+ memcg_list_lru_free(lru, src_idx);
}
-void memcg_drain_all_list_lrus(int src_idx, struct mem_cgroup *dst_memcg)
+void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *parent)
{
+ struct cgroup_subsys_state *css;
struct list_lru *lru;
+ int src_idx = memcg->kmemcg_id;
+
+ /*
+ * Change kmemcg_id of this cgroup and all its descendants to the
+ * parent's id, and then move all entries from this cgroup's list_lrus
+ * to ones of the parent.
+ *
+ * After we have finished, all list_lrus corresponding to this cgroup
+ * are guaranteed to remain empty. So we can safely free this cgroup's
+ * list lrus in memcg_list_lru_free().
+ *
+ * Changing ->kmemcg_id to the parent can prevent memcg_list_lru_alloc()
+ * from allocating list lrus for this cgroup after memcg_list_lru_free()
+ * call.
+ */
+ rcu_read_lock();
+ css_for_each_descendant_pre(css, &memcg->css) {
+ struct mem_cgroup *child;
+
+ child = mem_cgroup_from_css(css);
+ WRITE_ONCE(child->kmemcg_id, parent->kmemcg_id);
+ }
+ rcu_read_unlock();
mutex_lock(&list_lrus_mutex);
list_for_each_entry(lru, &memcg_list_lrus, list)
- memcg_drain_list_lru(lru, src_idx, dst_memcg);
+ memcg_reparent_list_lru(lru, src_idx, parent);
mutex_unlock(&list_lrus_mutex);
}
+
+static inline bool memcg_list_lru_allocated(struct mem_cgroup *memcg,
+ struct list_lru *lru)
+{
+ int idx = memcg->kmemcg_id;
+
+ return idx < 0 || xa_load(&lru->xa, idx);
+}
+
+int memcg_list_lru_alloc(struct mem_cgroup *memcg, struct list_lru *lru,
+ gfp_t gfp)
+{
+ int i;
+ unsigned long flags;
+ struct list_lru_memcg_table {
+ struct list_lru_memcg *mlru;
+ struct mem_cgroup *memcg;
+ } *table;
+ XA_STATE(xas, &lru->xa, 0);
+
+ if (!list_lru_memcg_aware(lru) || memcg_list_lru_allocated(memcg, lru))
+ return 0;
+
+ gfp &= GFP_RECLAIM_MASK;
+ table = kmalloc_array(memcg->css.cgroup->level, sizeof(*table), gfp);
+ if (!table)
+ return -ENOMEM;
+
+ /*
+ * Because the list_lru can be reparented to the parent cgroup's
+ * list_lru, we should make sure that this cgroup and all its
+ * ancestors have allocated list_lru_memcg.
+ */
+ for (i = 0; memcg; memcg = parent_mem_cgroup(memcg), i++) {
+ if (memcg_list_lru_allocated(memcg, lru))
+ break;
+
+ table[i].memcg = memcg;
+ table[i].mlru = memcg_init_list_lru_one(gfp);
+ if (!table[i].mlru) {
+ while (i--)
+ kfree(table[i].mlru);
+ kfree(table);
+ return -ENOMEM;
+ }
+ }
+
+ xas_lock_irqsave(&xas, flags);
+ while (i--) {
+ int index = READ_ONCE(table[i].memcg->kmemcg_id);
+ struct list_lru_memcg *mlru = table[i].mlru;
+
+ xas_set(&xas, index);
+retry:
+ if (unlikely(index < 0 || xas_error(&xas) || xas_load(&xas))) {
+ kfree(mlru);
+ } else {
+ xas_store(&xas, mlru);
+ if (xas_error(&xas) == -ENOMEM) {
+ xas_unlock_irqrestore(&xas, flags);
+ if (xas_nomem(&xas, gfp))
+ xas_set_err(&xas, 0);
+ xas_lock_irqsave(&xas, flags);
+ /*
+ * The xas lock has been released, this memcg
+ * can be reparented before us. So reload
+ * memcg id. More details see the comments
+ * in memcg_reparent_list_lrus().
+ */
+ index = READ_ONCE(table[i].memcg->kmemcg_id);
+ if (index < 0)
+ xas_set_err(&xas, 0);
+ else if (!xas_error(&xas) && index != xas.xa_index)
+ xas_set(&xas, index);
+ goto retry;
+ }
+ }
+ }
+ /* xas_nomem() is used to free memory instead of memory allocation. */
+ if (xas.xa_alloc)
+ xas_nomem(&xas, gfp);
+ xas_unlock_irqrestore(&xas, flags);
+ kfree(table);
+
+ return xas_error(&xas);
+}
#else
-static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
+static inline void memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
{
- return 0;
}
static void memcg_destroy_list_lru(struct list_lru *lru)
struct lock_class_key *key, struct shrinker *shrinker)
{
int i;
- int err = -ENOMEM;
#ifdef CONFIG_MEMCG_KMEM
if (shrinker)
else
lru->shrinker_id = -1;
#endif
- memcg_get_cache_ids();
lru->node = kcalloc(nr_node_ids, sizeof(*lru->node), GFP_KERNEL);
if (!lru->node)
- goto out;
+ return -ENOMEM;
for_each_node(i) {
spin_lock_init(&lru->node[i].lock);
init_one_lru(&lru->node[i].lru);
}
- err = memcg_init_list_lru(lru, memcg_aware);
- if (err) {
- kfree(lru->node);
- /* Do this so a list_lru_destroy() doesn't crash: */
- lru->node = NULL;
- goto out;
- }
-
+ memcg_init_list_lru(lru, memcg_aware);
list_lru_register(lru);
-out:
- memcg_put_cache_ids();
- return err;
+
+ return 0;
}
EXPORT_SYMBOL_GPL(__list_lru_init);
if (!lru->node)
return;
- memcg_get_cache_ids();
-
list_lru_unregister(lru);
memcg_destroy_list_lru(lru);
#ifdef CONFIG_MEMCG_KMEM
lru->shrinker_id = -1;
#endif
- memcg_put_cache_ids();
}
EXPORT_SYMBOL_GPL(list_lru_destroy);
projects / linux-2.6-microblaze.git / blobdiff