niceload - slow down a program when the load average is above a certain limit
niceload [-v] [-n nice] [-l load] [-t time] [-s time|-f factor] command
niceload [-v] [-n nice] [-l load] [-t time] [-s time|-f factor] -p=PID
GNU niceload will run a program when the load average is below a certain limit. When the limit is reached the program will be suspended for some time. Then resumed again for some time. Then the load load average is checked again and we start over.
If the load is 3.00 then the default settings will run a program like this:
run 1 second, suspend (3.00-1.00) seconds, run 1 second, suspend (3.00-1.00) seconds, run 1 second, ...
In terminal 1 run: top
In terminal 2 run:
niceload perl -e '$|=1;do{$l==$r or print ``.''; $l=$r}until(($r=time-$^T)>50)'
This will print a '.' every second for 50 seconds and eat a lot of CPU. When the load rises to 1.0 the process is suspended.
Running updatedb can often starve the system for disk I/O and thus result in a high load.
Run updatedb but suspend updatedb if the load is above 2.00:
niceload -l=2 updatedb
rsync can just like updatedb starve the system for disk I/O and thus result in a high load.
Run rsync but keep load below 3.4. If load reaches 7 sleep for (7-3.4)*12 seconds:
niceload -l=3.4 -f=12 rsync -Ha /home/ /backup/home/
None. In future versions $NICELOAD will be able to contain default settings.
Exit status should be the same as the command being run (untested).
Report bugs to <bug-parallel@gnu.org>.
Copyright (C) 2004-11-19 Ole Tange, http://ole.tange.dk
Copyright (C) 2005,2006,2006,2008,2009,2010 Ole Tange, http://ole.tange.dk
Copyright (C) 2010,2011 Ole Tange, http://ole.tange.dk and Free Software Foundation, Inc.
Copyright (C) 2010 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or at your option any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.
Permission is granted to copy, distribute and/or modify this documentation under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the file fdl.txt.
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A copy of the full license is included in the file as cc-by-sa.txt.
GNU niceload uses Perl, and the Perl modules POSIX, and Getopt::Long.
parallel(1), nice(1)