mm/list_lru: introduce list_lru_shrink_walk_irq()
Provide list_lru_shrink_walk_irq() and let it behave like
list_lru_walk_one() except that it locks the spinlock with
spin_lock_irq(). This is used by scan_shadow_nodes() because its lock
nests within the i_pages lock which is acquired with IRQ. This change
allows to use proper locking promitives instead hand crafted
lock_irq_disable() plus spin_lock().
There is no EXPORT_SYMBOL provided because the current user is in-kernel
only.
Add list_lru_shrink_walk_irq() which acquires the spinlock with the
proper locking primitives.
Link: http://lkml.kernel.org/r/20180716111921.5365-5-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/list_lru.c b/mm/list_lru.c
index f5c6a2d..5b30625 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -282,6 +282,21 @@ list_lru_walk_one(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
}
EXPORT_SYMBOL_GPL(list_lru_walk_one);
+unsigned long
+list_lru_walk_one_irq(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
+ list_lru_walk_cb isolate, void *cb_arg,
+ unsigned long *nr_to_walk)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
+ unsigned long ret;
+
+ spin_lock_irq(&nlru->lock);
+ ret = __list_lru_walk_one(nlru, memcg_cache_id(memcg), isolate, cb_arg,
+ nr_to_walk);
+ spin_unlock_irq(&nlru->lock);
+ return ret;
+}
+
unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
list_lru_walk_cb isolate, void *cb_arg,
unsigned long *nr_to_walk)
diff --git a/mm/workingset.c b/mm/workingset.c
index bc72ad0..4516dd7 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -483,13 +483,9 @@ static enum lru_status shadow_lru_isolate(struct list_head *item,
static unsigned long scan_shadow_nodes(struct shrinker *shrinker,
struct shrink_control *sc)
{
- unsigned long ret;
-
/* list_lru lock nests inside the IRQ-safe i_pages lock */
- local_irq_disable();
- ret = list_lru_shrink_walk(&shadow_nodes, sc, shadow_lru_isolate, NULL);
- local_irq_enable();
- return ret;
+ return list_lru_shrink_walk_irq(&shadow_nodes, sc, shadow_lru_isolate,
+ NULL);
}
static struct shrinker workingset_shadow_shrinker = {