Process Priority

p_nice

User-settable weighting factor (-20, 20)

• Negative numbers give higher priority

p_estcpu

Per-process estimated CPU usage

• Incremented whenever timer interrupt found process running
• Decayed every second while process runnable

• Where load is the sampled average of length of the the run queue plus short-term sleep queue over last minute
• The higher the load, the less p_estcpu decreases
  Run queue is determined by p_usrpri/4 where

• Clipped at 127

p_slptime

p_estcpu is not updated when the thread is asleep
When the thread becomes runnable again