1 files changed, 44 insertions, 0 deletions
diff --git a/debian/patches-rt/0181-mm-memcontrol-Disable-preemption-in-__mod_memcg_lruv.patch b/debian/patches-rt/0181-mm-memcontrol-Disable-preemption-in-__mod_memcg_lruv.patch
new file mode 100644
index 000000000..2df18df08
--- /dev/null
+++ b/debian/patches-rt/0181-mm-memcontrol-Disable-preemption-in-__mod_memcg_lruv.patch
@@ -0,0 +1,44 @@
+From 6f35e0e3a90abef410034d9900a21e68131aa5d5 Mon Sep 17 00:00:00 2001
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Wed, 28 Oct 2020 18:15:32 +0100
+Subject: [PATCH 181/323] mm/memcontrol: Disable preemption in
+ __mod_memcg_lruvec_state()
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz
+
+The callers expect disabled preemption/interrupts while invoking
+__mod_memcg_lruvec_state(). This works mainline because a lock of
+somekind 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.
+
+Cc: stable-rt@vger.kernel.org
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ mm/memcontrol.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/mm/memcontrol.c b/mm/memcontrol.c
+index ddc8ed096dec..49566afaef1c 100644
+--- a/mm/memcontrol.c
++++ b/mm/memcontrol.c
+@@ -816,6 +816,7 @@ 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);
+ 
+@@ -835,6 +836,7 @@ 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();
+ }
+ 
+ /**
+-- 
+2.43.0
+