diff --git a/activesupport/lib/active_support/buffered_logger.rb b/activesupport/lib/active_support/buffered_logger.rb
index c56dccc1f7d2f3c269a9e051c87fed030585ccee..c46386c6b09308fa308507b389292c017fcaa62a 100644
--- a/activesupport/lib/active_support/buffered_logger.rb
+++ b/activesupport/lib/active_support/buffered_logger.rb
@@ -39,6 +39,7 @@ def initialize(log, level = DEBUG)
       @level         = level
       @buffer        = []
       @auto_flushing = 1
+      @no_block = false
 
       if log.respond_to?(:write)
         @log = log
@@ -52,13 +53,19 @@ def initialize(log, level = DEBUG)
       end
     end
 
+    def set_non_blocking_io
+      if !RUBY_PLATFORM.match(/java|mswin/) && !(@log == STDOUT) && @log.respond_to?(:write_nonblock)
+        @no_block = true
+      end
+    end
+
     def add(severity, message = nil, progname = nil, &block)
       return if @level > severity
       message = (message || (block && block.call) || progname).to_s
       # If a newline is necessary then create a new message ending with a newline.
       # Ensures that the original message is not mutated.
       message = "#{message}\n" unless message[-1] == ?\n
-      @buffer << message
+      buffer << message
       auto_flush
       message
     end
@@ -90,7 +97,13 @@ def auto_flushing=(period)
     end
 
     def flush
-      @log.write(@buffer.slice!(0..-1).join) unless @buffer.empty?
+      unless buffer.empty?
+        if @no_block
+          @log.write_nonblock(buffer.slice!(0..-1).join)
+        else
+          @log.write(buffer.slice!(0..-1).join)
+        end
+      end
     end
 
     def close
@@ -101,7 +114,7 @@ def close
 
     protected
       def auto_flush
-        flush if @buffer.size >= @auto_flushing
+        flush if buffer.size >= @auto_flushing
       end
   end
 end
diff --git a/railties/lib/initializer.rb b/railties/lib/initializer.rb
index c3056c196dacfc0340028aed9c96619b390a74a8..899688b55949417bae0bbc02b2f453df0f0f5e48 100644
--- a/railties/lib/initializer.rb
+++ b/railties/lib/initializer.rb
@@ -250,7 +250,10 @@ def initialize_logger
         begin
           logger = ActiveSupport::BufferedLogger.new(configuration.log_path)
           logger.level = ActiveSupport::BufferedLogger.const_get(configuration.log_level.to_s.upcase)
-          logger.auto_flushing = false if configuration.environment == "production"
+          if configuration.environment == "production"
+            logger.auto_flushing = false
+            logger.set_non_blocking_io
+          end
         rescue StandardError =>e
           logger = ActiveSupport::BufferedLogger.new(STDERR)
           logger.level = ActiveSupport::BufferedLogger::WARN