PS User Commands
NAME
ps - Process List
SYNOPSIS
ps [OPTIONS]
DESCRIPTION
Lists currently active processes along with the Process ID (PID). Processes
are listing in order of decreasing demand on the CPU (%). This command also
displays the current uptime.
-V
Provides additional process information.
runtime - Total runtime accumulated
% - percentage of CPU usage
mem - Amount of memory in use (KB)
msg - Number of inter-process messages pending (should be 0)
hnd - Number of handles allocated
stk - Maximum stack usage (percent)
frm - Count of Stack frames (Applications)
pram - available internal processor RAM
-M [N] [LOGFILES]
The PS command displays the process activity at a moment in time. As
this activity can at times be very dynamic, two successive PS commands
might display dramatically different results. Processes my be added. Others
may terminate. Still others normally dormant might get busy. The -M option
monitors the process status dynamically updating the display every couple
of seconds. Any keystroke will exit from this mode.
An optional log file such as
jniorsys.log or list of log files may be
provided. These files are monitored for newly appended lines which are
then displayed as notifications. This offers a convenient means for
correlating changes in process activity to logged events.
The [N] option specifies an approximate number of log lines to
display before rolling. N is 5 lines by default and is constrained
to a number between 5 and 20.
NOTES
Developers want to insure that an application does not monopolize CPU
resources. An application abnormally accumulating runtime may benefit
from the use of process sleep() and yield() functions where appropriate.
Stack usage above 50% should be watched carefully. Use of recursive routines
in programs can drive stack usage up. A program will assert and stop should
it use up the available stack space.
Handles are required for various I/O activities and should be released if
no longer required. These are a limited resource as well.
Inter-process messaging is essential in creating functionality like
custom protocols. The application program creates a message pump/queue
in order to send and receive such messages. It is imperative that the
queue be serviced promptly. A building msg count signals a messaging
issue which certainly will impact system performance.
The Idle Process should typically involve 90% or more of the CPU time. Other
tasks may at times have work to do and require 100% of the CPU for certain
possible extended periods of time. This is normal. The CPU however should
return to the Idle state at some point. If this does not occur it may
indicate that some process is not performing efficiently and may require
modification.
SEE ALSO
HELP Topics:
THD,
KILL,
STOP
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