[PATCH v2] mm: workingset: replace IRQ-off check with a lockdep assert.

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

Commit

  68d48e6a2df57 ("mm: workingset: add vmstat counter for shadow nodes")

introduced an IRQ-off check to ensure that a lock is held which also
disabled interrupts. This does not work the same way on -RT because none
of the locks, that are held, disable interrupts.
Replace this check with a lockdep assert which ensures that the lock is
held.

Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
v1…v2: lockdep_is_held() => lockdep_assert_held()

 mm/workingset.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -368,6 +368,8 @@ static struct list_lru shadow_nodes;
 
 void workingset_update_node(struct xa_node *node)
 {
+	struct address_space *mapping;
+
 	/*
 	 * Track non-empty nodes that contain only shadow entries;
 	 * unlink those that contain pages or are being freed.
@@ -376,7 +378,8 @@ void workingset_update_node(struct xa_no
 	 * already where they should be. The list_empty() test is safe
 	 * as node->private_list is protected by the i_pages lock.
 	 */
-	VM_WARN_ON_ONCE(!irqs_disabled());  /* For __inc_lruvec_page_state */
+	mapping = container_of(node->array, struct address_space, i_pages);
+	lockdep_assert_held(&mapping->i_pages.xa_lock);
 
 	if (node->count && node->count == node->nr_values) {
 		if (list_empty(&node->private_list)) {