From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
On PREEMPT_RT interrupts and preemption is always enabled. The locking
function __memcg_stats_lock() always disabled preemptions. The recently
added checks need to performed only on !PREEMPT_RT where preemption and
disabled interrupts are used.
Please fold into:
"Protect per-CPU counter by disabling preemption on PREEMPT_RT"
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
[do: backported to v5.15]
Signed-off-by: David Oberhollenzer <goliath@xxxxxxxxxxxx>
---
mm/memcontrol.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 70c374761bb8..74025c2e2bcc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -773,7 +773,7 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
* interrupt context while other caller need to have disabled interrupt.
*/
__memcg_stats_lock();
- if (IS_ENABLED(CONFIG_DEBUG_VM)) {
+ if (IS_ENABLED(CONFIG_DEBUG_VM) && !IS_ENABLED(CONFIG_PREEMPT_RT)) {
switch (idx) {
case NR_ANON_MAPPED:
case NR_FILE_MAPPED:
--
2.37.1
