mm, memcg: prevent missed memory.low load tears
diff mbox series

Message ID 20200612174437.GA391453@chrisdown.name
State Accepted
Commit fce0ed6224c1cc13f85841c7cc75e3b3cb0acae9
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Series
  • mm, memcg: prevent missed memory.low load tears
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Commit Message

Chris Down June 12, 2020, 5:44 p.m. UTC
Looks like one of these got missed when massaging in f86b810c2610 ("mm,
memcg: prevent memory.low load/store tearing") with other linux-mm
changes.

Reported-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Chris Down <chris@chrisdown.name>
---
 mm/memcontrol.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Michal Hocko June 15, 2020, 6:42 a.m. UTC | #1
On Fri 12-06-20 18:44:37, Chris Down wrote:
> Looks like one of these got missed when massaging in f86b810c2610 ("mm,
> memcg: prevent memory.low load/store tearing") with other linux-mm
> changes.
> 
> Reported-by: Michal Koutný <mkoutny@suse.com>
> Signed-off-by: Chris Down <chris@chrisdown.name>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  mm/memcontrol.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 0b38b6ad547d..f7cc66a80348 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -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:
> -- 
> 2.27.0
>

Patch
diff mbox series

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0b38b6ad547d..f7cc66a80348 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -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: