From e4c042fcfd6ebde4252b203e650b37e0bab314df Mon Sep 17 00:00:00 2001
From: Tim Besard <tim.besard@gmail.com>
Date: Thu, 10 Aug 2017 09:11:10 +0200
Subject: [PATCH] Substract cache from memory usage.

---
 docker_memory | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/docker_memory b/docker_memory
index 1d84804..1d32cb0 100755
--- a/docker_memory
+++ b/docker_memory
@@ -70,6 +70,16 @@ for my $i (1 .. $#containers)
    {
       my $memory_bytes = <$file>;
       $memory_bytes =~ s/\s+$//;
+      if (open(my $file, '<', "/sys/fs/cgroup/memory/docker/$id/memory.stat"))
+      {
+         my %stat;
+         while (my $line = <$file>)
+         {
+            $line =~ m/^(\w+) (\d+)$/;
+            $stat{$1} = $2;
+         }
+         $memory_bytes -= $stat{"cache"};
+      }
       push @result, {'name'=>$name, 'memory_bytes'=>$memory_bytes};
    }
 }