Watsup User Guide

Introduction
Watsup monitors Linux system resources and the processes using those resources.
  +  Overhead is low, supporting sub-second sampling period
  +  Overall system and top process resources are shown on one page
  +  CPU, memory, disk I/O, network I/O, and page faults are monitored
  +  Font can be set small (for display in a corner of the screen)
  +  The N top-ranked processes fitting in the window are shown
  +  Minimal jumping around between samples (easier to watch a process)
  +  Process rank is weighted sum of recent CPU, hard faults, and disk I/O
  +  A process can be selected with the mouse and killed
  +  Optionally filter for given users, PIDs, or exe file names

Screenshot


License and Warranty
Watsup is a free program licensed under the GNU General Public License v.3 (Free Software Foundation). Watsup is not warranted for any purpose, but if you find a bug I will try to fix it.

Origin and Contact
Watsup originates from the author's web site http://kornelix.squarespace.com/watsup
Other web sites may offer it for download. Modifications may have been made.
If you have questions, suggestions or a bug to report: kornelix@yahoo.de

toolbar buttons

button	function
parms	dialog for setting the sample period, report font, process match strings
root	restart with root privileges (if sudo password is OK)
start	start sampling and reporting
stop	stop sampling and reporting
sort	sort process list in decreasing order of recent average resource usage
save	save current screen to a data file
print	print current screen on default printer
quit	exit the application
help	display help file (this file)

system resources reported

parameter	description	source
period	sample interval, seconds	system clock
CPU	% CPU load (max = no. SMPs x 100)	/proc/stat
memory MB	real memory used for processes, disk cache, and free	/proc/meminfo
PFs/sec	page faults/sec, hard and soft	/proc/vmstat
disk/sec	disk I/O ops/sec and MB/sec	/proc/diskstats
net KB/sec	network kilobytes/sec received and sent	/proc/net/dev

process resources reported

parameter	destription	source
PID	process ID	/proc/<pid>
CPU	% CPU used by process	/proc/<pid>/stat
real MBs	real megabytes used by process	/proc/<pid>/stat
hard PF/s	process hard page faults/sec	/proc/<pid>/stat
I/O MB/s	process disk I/O, MB/sec (see note below)	/proc/<pid>/io
User	login user name	/proc/<pid>/environ
Executable	executable file name	/proc/<pid>/exe

methodology
The process data files under /proc contain current data for memory usage, and counters that continuously increment for other resources (CPU time, disk and network I/O, page faults). Resource usage rates are calculated as (current value - prior value) divided by (sample interval).

CPU
The total CPU load is based on 1 CPU = 100%. Thus a system having N CPUs has a maximum load value of N x 100 percent.

page faults
Hard page faults are those requiring physical I/O, and soft faults are those which use free memory or stale pages from other processes. Modern CPUs can support over 100K soft faults per second. Soft fault overhead is also reflected in the CPU load.

cached memory
Memory not needed by active processes is used for disk caching. This memory is available for processes when needed.

process CPU
The CPU % used by a process can exceed 100% for multi-threaded processes utilizing multiple CPUs. The maximum possible value is 100 x CPU count. Modern processors have 1 to 4 CPUs and 0 to 4 "hyperthread" CPUs which have a part of the capacity of a real CPU. CPU time for a subprocess is added to the main process CPU time when the subprocess completes. This is more accurate for short subprocesses that would otherwise not be counted. For longer running subprocesses it causes a double count for one interval when the subprocess completes.

process disk I/O
This is a new kernel feature that may not be enabled. Watsup reads the files /proc/pid/io but does not complain if they do not exist. It works for Ubuntu 8.10 and later.

running as root
This is necessary to see all processes. Otherwise most processes owned by root or other users are not shown. Use the [root] button and enter the password (same as sudo).

killing a process
Click on any process in the list. A dialog pops up which shows the selected process PID and executable file name. Confirm or cancel the selection. If confirmed, the process is killed. This must be a process you own, or watsup must be running as root.

show selected processes
In the [parms] button dialog box, enter one or more strings separated by blanks. Only processes with a username, PID, or exe file name matching one of these strings will be displayed. The strings may have wildcards, e.g. "gnome*" will show the many processes with exe files named "gnome-xxxxx".