Re: [PATCH v3 2/2] mm, memcg: Decouple e{low,min} state mutations from protection checks

[Chris Down]

Naresh Kamboju writes:
> This patch is causing oom-killer while running mkfs -t ext4 on i386 kernel
> running on x86_64 machine version linux-next 5.7.0-rc6-next-20200521.

I think I see what's wrong here -- if we bail out early, memory.e{min,low} 
might be uninitialised.

Does this patch fix it, by any chance?

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d3b23c57bed4..aa902b9cbb79 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5046,6 +5046,9 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 			memory_cgrp_subsys.broken_hierarchy = true;
 	}
 
+	memcg->memory.emin = 0;
+	memcg->memory.elow = 0;
+
 	/* The following stuff does not apply to the root */
 	if (!parent) {
 #ifdef CONFIG_MEMCG_KMEM
--
2.26.2