From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-mm@kvack.org
Cc: tglx@linutronix.de, Andrew Morton <akpm@linux-foundation.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Kirill Tkhai <ktkhai@virtuozzo.com>
Subject: [PATCH 1/3] mm: workingset: remove local_irq_disable() from count_shadow_nodes()
Date: Fri, 22 Jun 2018 17:12:19 +0200 [thread overview]
Message-ID: <20180622151221.28167-2-bigeasy@linutronix.de> (raw)
In-Reply-To: <20180622151221.28167-1-bigeasy@linutronix.de>
In commit 0c7c1bed7e13 ("mm: make counting of list_lru_one::nr_items
lockless") the
spin_lock(&nlru->lock);
statement was replaced with
rcu_read_lock();
in __list_lru_count_one(). The comment in count_shadow_nodes() says that
the local_irq_disable() is required because the lock must be acquired
with disabled interrupts and (spin_lock()) does not do so.
Since the lock is replaced with rcu_read_lock() the local_irq_disable()
is no longer needed. The code path is
list_lru_shrink_count()
-> list_lru_count_one()
-> __list_lru_count_one()
-> rcu_read_lock()
-> list_lru_from_memcg_idx()
-> rcu_read_unlock()
Remove the local_irq_disable() statement.
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
mm/workingset.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/mm/workingset.c b/mm/workingset.c
index 40ee02c83978..ed8151180899 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -366,10 +366,7 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
unsigned long nodes;
unsigned long cache;
- /* list_lru lock nests inside the IRQ-safe i_pages lock */
- local_irq_disable();
nodes = list_lru_shrink_count(&shadow_nodes, sc);
- local_irq_enable();
/*
* Approximate a reasonable limit for the radix tree nodes
--
2.18.0
next prev parent reply other threads:[~2018-06-22 15:12 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-22 15:12 [PATCH 0/3] mm: use irq locking suffix instead local_irq_disable() Sebastian Andrzej Siewior
2018-06-22 15:12 ` Sebastian Andrzej Siewior [this message]
2018-06-24 19:51 ` [PATCH 1/3] mm: workingset: remove local_irq_disable() from count_shadow_nodes() Vladimir Davydov
2018-06-25 10:36 ` Kirill Tkhai
2018-06-22 15:12 ` [PATCH 2/3] mm: workingset: make shadow_lru_isolate() use locking suffix Sebastian Andrzej Siewior
2018-06-24 19:57 ` Vladimir Davydov
2018-06-26 21:25 ` Sebastian Andrzej Siewior
2018-06-27 8:50 ` Vladimir Davydov
2018-06-27 9:20 ` Sebastian Andrzej Siewior
2018-06-28 9:30 ` Vladimir Davydov
2018-07-02 22:38 ` Sebastian Andrzej Siewior
2018-06-22 15:12 ` [PATCH 3/3] mm: list_lru: Add lock_irq member to __list_lru_init() Sebastian Andrzej Siewior
2018-06-24 20:09 ` Vladimir Davydov
2018-07-03 14:52 ` Sebastian Andrzej Siewior
2018-07-03 14:52 ` [PATCH 1/4] mm/list_lru: use list_lru_walk_one() in list_lru_walk_node() Sebastian Andrzej Siewior
2018-07-03 14:52 ` [PATCH 2/4] mm/list_lru: Move locking from __list_lru_walk_one() to its caller Sebastian Andrzej Siewior
2018-07-03 14:52 ` [PATCH 3/4] mm/list_lru: Pass struct list_lru_node as an argument __list_lru_walk_one() Sebastian Andrzej Siewior
2018-07-03 14:52 ` [PATCH 4/4] mm/list_lru: Introduce list_lru_shrink_walk_irq() Sebastian Andrzej Siewior
2018-07-03 21:14 ` Andrew Morton
2018-07-03 21:44 ` Re: Sebastian Andrzej Siewior
2018-07-04 14:44 ` Re: Vladimir Davydov
2018-06-22 21:39 ` [PATCH 0/3] mm: use irq locking suffix instead local_irq_disable() Andrew Morton
2018-06-24 20:10 ` Vladimir Davydov
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