mm: workingset: replace IRQ-off check with a lockdep assert.

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 PREEMPT_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.

Link: https://lkml.kernel.org/r/20220301122143.1521823-3-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.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/workingset.c b/mm/workingset.c
index 979c713..6f616a6 100644 (file)
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -433,6 +433,8 @@ 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.
@@ -441,7 +443,8 @@ void workingset_update_node(struct xa_node *node)
         * 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)) {