diff options
Diffstat (limited to 'mm/list_lru.c')
| -rw-r--r-- | mm/list_lru.c | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/mm/list_lru.c b/mm/list_lru.c index 490473af3122..ec48b5dadf51 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -60,30 +60,34 @@ list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx) return &lru->node[nid].lru; } +static inline bool lock_list_lru(struct list_lru_one *l, bool irq) +{ + if (irq) + spin_lock_irq(&l->lock); + else + spin_lock(&l->lock); + if (unlikely(READ_ONCE(l->nr_items) == LONG_MIN)) { + if (irq) + spin_unlock_irq(&l->lock); + else + spin_unlock(&l->lock); + return false; + } + return true; +} + static inline struct list_lru_one * lock_list_lru_of_memcg(struct list_lru *lru, int nid, struct mem_cgroup *memcg, bool irq, bool skip_empty) { struct list_lru_one *l; - long nr_items; rcu_read_lock(); again: l = list_lru_from_memcg_idx(lru, nid, memcg_kmem_id(memcg)); - if (likely(l)) { - if (irq) - spin_lock_irq(&l->lock); - else - spin_lock(&l->lock); - nr_items = READ_ONCE(l->nr_items); - if (likely(nr_items != LONG_MIN)) { - rcu_read_unlock(); - return l; - } - if (irq) - spin_unlock_irq(&l->lock); - else - spin_unlock(&l->lock); + if (likely(l) && lock_list_lru(l, irq)) { + rcu_read_unlock(); + return l; } /* * Caller may simply bail out if raced with reparenting or |