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dkim=pass header.d=bytedance-com.20150623.gappssmtp.com header.s=20150623 header.b=lcF2FdRL; spf=pass (imf16.hostedemail.com: domain of songmuchun@bytedance.com designates 209.85.214.178 as permitted sender) smtp.mailfrom=songmuchun@bytedance.com; dmarc=pass (policy=none) header.from=bytedance.com X-HE-Tag: 1631604811-774062 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Since commit e5bc3af7734f ("rcu: Consolidate PREEMPT and !PREEMPT synchronize_rcu()"), the critical section of spin lock can serve as an RCU read-side critical section which already allows readers that hold nlru->lock avoid taking rcu lock. So just to remove holding lock. Signed-off-by: Muchun Song --- mm/list_lru.c | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/mm/list_lru.c b/mm/list_lru.c index 4962d48d4410..6b2f3cbe5f67 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -402,18 +402,7 @@ 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; }