Top command introduction

columns:

　　PR: priority of the task, RT means the highest priority, running in real time priority.

　　NI: nice value. A negative means high priority, whearas a positive value means low priority. Zero means priority willnot change.

　　VIRT: visual memory in total used by the task.

　　RES: resident memory size. The non-swapped physical memory.

　　SHR: shared memory size. Potentialy shared by other tasks.

　　S: status of the task.

　　　　'D' = uninterruptible sleep
　　　　'R' = running
　　　　'S' = sleeping
　　　　'T' = traced or stopped
　　　　'Z' = zombie

　　%CPU: the task costs the elapsed CPU time.

      %MEM: the task uses the percentage of Physical memory. RES/%MEM=Total MM.

　　TIME+: unit is hundredths. 1/100s.