diff options
| author | Muchun Song <songmuchun@bytedance.com> | 2021-11-05 13:37:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-06 13:30:35 -0700 |
| commit | 60ec6a48eec24986a6414740a2481d22efc1b2f9 (patch) | |
| tree | 0132f7845f227774a39350d459b664ee8ec59515 /mm | |
| parent | 58056f77502f3567b760c9a8fc8d2e9081515b2d (diff) | |
mm: list_lru: remove holding lru lock
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 to avoid taking rcu lock. So just remove holding lock.
Link: https://lkml.kernel.org/r/20211025124534.56345-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/list_lru.c | 11 |
1 files changed, 0 insertions, 11 deletions
diff --git a/mm/list_lru.c b/mm/list_lru.c index a6031f1c5bd7..9a1f7df1afc9 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -398,18 +398,7 @@ static int memcg_update_list_lru_node(struct list_lru_node *nlru, } memcpy(&new->lru, &old->lru, flex_array_size(new, lru, old_size)); - - /* - * 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; } |