Skip to contentSkip to conversation

mm, memcg: prevent missed memory.low load tears

PATCH Applied Chris Down 2 participants 2 messages Jun 12, 2020 – Jun 15, 2020

Subsystems (2)
lore
Share & tools
lore

Chris Down

author
#0 lore raw

PATCH 1/1 mm, memcg: prevent missed memory.low load tears

Looks like one of these got missed when massaging in f86b810c2610 ("mm,
memcg: prevent memory.low load/store tearing") with other linux-mm changes.

---
 mm/memcontrol.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
mm/memcontrol.c +3 -2
index 0b38b6ad547d..f7cc66a80348 100644
@@ -6416,7 +6416,7 @@ enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,
 
 	if (parent == root) {
 		memcg->memory.emin = READ_ONCE(memcg->memory.min);
-		memcg->memory.elow = memcg->memory.low;
+		memcg->memory.elow = READ_ONCE(memcg->memory.low);
 		goto out;
 	}
 
@@ -6428,7 +6428,8 @@ enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,
 			atomic_long_read(&parent->memory.children_min_usage)));
 
 	WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usage,
-			memcg->memory.low, READ_ONCE(parent->memory.elow),
+			READ_ONCE(memcg->memory.low),
+			READ_ONCE(parent->memory.elow),
 			atomic_long_read(&parent->memory.children_low_usage)));
 
 out:
Signature · 1 line
2.27.0
maintainer Acked-by on v1 1/1
#1 lore raw
Quoted 6 lines · Chris Down

Looks like one of these got missed when massaging in f86b810c2610 ("mm,
memcg: prevent memory.low load/store tearing") with other linux-mm changes.

Quoted 30 lines
---
 mm/memcontrol.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
mm/memcontrol.c +3 -2
index 0b38b6ad547d..f7cc66a80348 100644
@@ -6416,7 +6416,7 @@ enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,
 
 	if (parent == root) {
 		memcg->memory.emin = READ_ONCE(memcg->memory.min);
-		memcg->memory.elow = memcg->memory.low;
+		memcg->memory.elow = READ_ONCE(memcg->memory.low);
 		goto out;
 	}
 
@@ -6428,7 +6428,8 @@ enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,
 			atomic_long_read(&parent->memory.children_min_usage)));
 
 	WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usage,
-			memcg->memory.low, READ_ONCE(parent->memory.elow),
+			READ_ONCE(memcg->memory.low),
+			READ_ONCE(parent->memory.elow),
 			atomic_long_read(&parent->memory.children_low_usage)));
 
 out:
Signature · 1 line
2.27.0
Signature · 2 lines
Michal Hocko
SUSE Labs