2 files changed, 15 insertions, 8 deletions
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 10281d60eb..6a6c861458 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -143,13 +143,13 @@ module ActiveSupport
           log("miss", key, options)
 
           value = nil
-          seconds = Benchmark.realtime { value = yield }
+          ms = Benchmark.ms { value = yield }
 
           @logger_off = true
           write(key, value, options)
           @logger_off = false
 
-          log("write (will save #{'%.2f' % (seconds * 1000)}ms)", key, nil)
+          log('write (will save %.2fms)' % ms, key, nil)
 
           value
         end
diff --git a/activesupport/lib/active_support/core_ext/benchmark.rb b/activesupport/lib/active_support/core_ext/benchmark.rb
index 79ba165e3a..ae57b152e8 100644
--- a/activesupport/lib/active_support/core_ext/benchmark.rb
+++ b/activesupport/lib/active_support/core_ext/benchmark.rb
@@ -1,12 +1,19 @@
 require 'benchmark'
 
 class << Benchmark
-  remove_method :realtime
+  # Earlier Ruby had a slower implementation.
+  if RUBY_VERSION < '1.8.7'
+    remove_method :realtime
 
-  def realtime
-    r0 = Time.now
-    yield
-    r1 = Time.now
-    r1.to_f - r0.to_f
+    def realtime
+      r0 = Time.now
+      yield
+      r1 = Time.now
+      r1.to_f - r0.to_f
+    end
+  end
+
+  def ms
+    1000 * realtime { yield }
   end
 end