From 8928d487defbc916d145d83d9cbde3d3aef3993e Mon Sep 17 00:00:00 2001
From: Victor Marmol <vmarmol@google.com>
Date: Mon, 11 May 2015 09:43:11 -0700
Subject: [PATCH] Min working set should be 0.

Fixes #685
---
 container/libcontainer/helpers.go | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/container/libcontainer/helpers.go b/container/libcontainer/helpers.go
index d5bf142a..560d8eb6 100644
--- a/container/libcontainer/helpers.go
+++ b/container/libcontainer/helpers.go
@@ -186,10 +186,21 @@ func toContainerStats2(s *cgroups.Stats, ret *info.ContainerStats) {
 		ret.Memory.HierarchicalData.Pgmajfault = v
 	}
 	if v, ok := s.MemoryStats.Stats["total_inactive_anon"]; ok {
-		ret.Memory.WorkingSet = ret.Memory.Usage - v
-		if v, ok := s.MemoryStats.Stats["total_active_file"]; ok {
-			ret.Memory.WorkingSet -= v
+		workingSet := ret.Memory.Usage
+		if workingSet < v {
+			workingSet = 0
+		} else {
+			workingSet -= v
 		}
+
+		if v, ok := s.MemoryStats.Stats["total_active_file"]; ok {
+			if workingSet < v {
+				workingSet = 0
+			} else {
+				workingSet -= v
+			}
+		}
+		ret.Memory.WorkingSet = workingSet
 	}
 }