NAME¶
loadwatch - run a program when machine is idle
SYNOPSIS¶
loadwatch [
options]
-p pid | [--]
prog
[
args]
DESCRIPTION¶
loadwatch either spawns a child process
prog with the arguments
args and controls it with all its process group, or takes control of an
already running process with pid
pid with all its process group.
loadwatch allows the controlled processes to run while the load average
remains below
high_limit. Every
delay seconds,
loadwatch
checks the load average. If the load is above
high_limit, the child is
suspended; the child is resumed when the load falls below
low_limit.
OPTIONS¶
A summary of options is included below.
- -h high_limit
- A decimal value that sets the system load at which the
child process will be suspended. (Default: 1.25)
- -l low_limit
- A decimal value that sets the system load at which the
child process will be resumed. (Default: 0.25)
- -d delay
- An integral number of seconds that sets how often the
system load will be checked. (Default: 10)
- -n copies
- An integer value that sets the number of copies of
prog to run. (Default: 1)
- -u file
- Create a UNIX domain socket file for use by
lw-ctl.
- -p pid
- The pid of the program that should be controlled by
loadwatch (with all its process group).
SEE ALSO¶
lw-ctl(1),
nice(1)
BUGS¶
You should choose
low_limit and
high_limit carefully. When the
load drops below
low_limit, the process(es) will be resumed, and it
should not, by itself, cause the load to raise above
high_limit, or the
whole will oscillate, periodically suspending and resuming the process(es).
Similarly, if several instances of loadwatch are running, they may resume their
processes at the same time, leading to oscillations if the limits are not
carefully chosen. Hence, each instance of loadwatch affects every other
instance on the computer, and should not be considered in isolation.
AUTHOR¶
This manual page was written by Dale E. Martin <dmartin@debian.org>, for
the Debian GNU/Linux system (but may be used by others). It was then updated
by Nicolas Boullis <nboullis@debian.org>.