Linux-rt-users Archive on
 help / color / Atom feed
* [PATCH RT] mm/memcontrol: Disable preemption in __mod_memcg_lruvec_state()
@ 2020-10-28 19:10 Sebastian Andrzej Siewior
  0 siblings, 0 replies; only message in thread
From: Sebastian Andrzej Siewior @ 2020-10-28 19:10 UTC (permalink / raw)
  To: LKML; +Cc: Thomas Gleixner, linux-rt-users, Steven Rostedt

The callers expect disabled preemption/interrupts while invoking
__mod_memcg_lruvec_state(). This works mainline because a lock of
some kind is acquired.

Use preempt_disable_rt() where per-CPU variables are accessed and a
stable pointer is expected. This is also done in __mod_zone_page_state()
for the same reason.

Signed-off-by: Sebastian Andrzej Siewior <>
 mm/memcontrol.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f35ffe52cc4f8..09fa87f7a8119 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -829,6 +829,7 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
 	memcg = pn->memcg;
+	preempt_disable_rt();
 	/* Update memcg */
 	__mod_memcg_state(memcg, idx, val);
@@ -848,6 +849,7 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 		x = 0;
 	__this_cpu_write(pn->lruvec_stat_cpu->count[idx], x);
+	preempt_enable_rt();

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, back to index

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-28 19:10 [PATCH RT] mm/memcontrol: Disable preemption in __mod_memcg_lruvec_state() Sebastian Andrzej Siewior

Linux-rt-users Archive on

Archives are clonable:
	git clone --mirror linux-rt-users/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-rt-users linux-rt-users/ \
	public-inbox-index linux-rt-users

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone