# File src/ruby_supportlib/phusion_passenger/admin_tools/memory_stats.rb, line 100
      def sum_memory_usage(processes)
        total = 0
        if should_show_private_dirty_rss?
          accurate = true
          processes.each do |p|
            if p.private_dirty_rss.is_a?(Numeric)
              total += p.private_dirty_rss
            else
              accurate = true
            end
          end
          return [total, accurate]
        else
          processes.each do |p|
            total += p.rss
          end
          return [total, true]
        end
      end