memcg is NULL if we have CONFIG_MEMCG set, but cgroup_disable=memory on the kernel command line. Fixes: 8a907cdf0177ab40 ("mm, memcg: proportional memory.{low,min} reclaim") Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Chris Down <chris@xxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: cgroups@xxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx --- include/linux/memcontrol.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 290cfbfd60cd..49742489aa56 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -335,6 +335,9 @@ static inline bool mem_cgroup_disabled(void) static inline unsigned long mem_cgroup_protection(struct mem_cgroup *memcg) { + if (mem_cgroup_disabled()) + return 0; + return max(READ_ONCE(memcg->memory.emin), READ_ONCE(memcg->memory.elow)); } -- 2.20.1