making sense of latency top

   LatencyTOP version 0.5       (C) 2008 Intel Corporation

Cause                                                Maximum     Percentage
Reading from file                                 1357.4 msec          5.9 %
[sleep_on_page]                                   449.0 msec         62.0 %
Reading directory content                         251.1 msec         13.3 %
Page fault                                         23.8 msec          0.4 %
Removing directory                                 12.5 msec          0.1 %
Writing to file                                    11.6 msec          0.2 %
opening cdrom device                                5.6 msec          0.1 %
Waiting for event (select)                          5.0 msec          5.3 %
Waiting for event (poll)                            5.0 msec          9.6 %



Process dolphin (10669)                    Total: 4682.8 msec
Reading from file                                 1357.4 msec         43.9 %
[sleep_on_page]                                    54.6 msec         50.8 %
Page fault                                         15.6 msec          2.2 %
opening cdrom device                                5.6 msec          0.9 %
Waiting for event (poll)                            5.0 msec          2.2 %