IOTOP Display Query

[Stephen Morris]

HI,
     When I run IOTOP, the first column is TID, what is TID? This 
display is showing in excess of 50 entries for Thunderbird where all of 
them have a unique TID value, is Thunderbird really starting that many 
threads?
     Also when I run IOTOP I get a display in the middle of the screen 
that says "task_delayacct is OFF press Ctrl-T to toggle". If I press 
ctrl-t to toggle it on it stop displaying the item consuming the most 
I/O at the top of the display, and if I toggle it back off it goes back 
to showing the biggest I/O consumer at the top. What is task_delayacct 
and what is IOTOP doing with it?

regards,
Steve