From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> v4.19.152-rt66-rc1 stable review patch. If anyone has any objections, please let me know. ----------- [ Upstream commit 74858f0d38a8d3c069a0745ff53ae084c8e7cabb ] 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@xxxxxxxxxxxxxxx Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx> Conflicts: mm/memcontrol.c --- include/linux/memcontrol.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index cc6b6532eb56..dbb2c4e27277 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -665,6 +665,7 @@ static inline void __mod_lruvec_state(struct lruvec *lruvec, pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); + preempt_disable_rt(); /* Update memcg */ __mod_memcg_state(pn->memcg, idx, val); @@ -675,6 +676,7 @@ static inline void __mod_lruvec_state(struct lruvec *lruvec, x = 0; } __this_cpu_write(pn->lruvec_stat_cpu->count[idx], x); + preempt_enable_rt(); } static inline void mod_lruvec_state(struct lruvec *lruvec, -- 2.17.1
