Message ID | 20210511104647.604-6-songmuchun@bytedance.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show
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Series |
Optimize list lru memory consumption
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expand
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diff --git a/mm/list_lru.c b/mm/list_lru.c index 4962d48d4410..e86d4d055d3c 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -403,18 +403,9 @@ static int memcg_update_list_lru_node(struct list_lru_node *nlru, memcpy(&new->lru, &old->lru, old_size * sizeof(void *)); - /* - * The locking below allows readers that hold nlru->lock avoid taking - * rcu_read_lock (see list_lru_from_memcg_idx). - * - * 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); rcu_assign_pointer(nlru->memcg_lrus, new); - spin_unlock_irq(&nlru->lock); - kvfree_rcu(old, rcu); + return 0; }
Since commit e5bc3af7734f ("rcu: Consolidate PREEMPT and !PREEMPT synchronize_rcu()"), the critical section of spinlock can serve as RCU read-side critical section. So we can remove redundant locking from memcg_update_list_lru_node(). Signed-off-by: Muchun Song <songmuchun@bytedance.com> --- mm/list_lru.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-)