NAME¶
niceload - slow down a program when the load average is above a certain limit
SYNOPSIS¶
niceload [-v] [-h] [-n nice] [-I io] [-L load] [-M mem] [-N] [--sensor
program] [-t time] [-s time|-f factor] ( command | -p PID [-p PID ...] )
DESCRIPTION¶
GNU
niceload will slow down a program when the load average (or other
system activity) is above 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 average is checked again and we start over.
Instead of load average
niceload can also look at disk I/O, amount of
free memory, or swapping activity.
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, ...
OPTIONS¶
- -f FACTOR
- --factor FACTOR
- Suspend time factor. Dynamically set -s as amount over limit *
factor. Default is 1.
- -H
- --hard
- Hard limit. --hard will suspend the process until the system is
under the limits. The default is --soft.
- --io iolimit
- -I iolimit
- Limit for I/O. The amount of disk I/O will be computed as a value 0 - 10,
where 0 is no I/O and 10 is at least one disk is 100% saturated.
--io will set both --start-io and run-io.
- --load loadlimit
- -L loadlimit
- Limit for load average.
--load will set both --start-load and run-load.
- --mem memlimit
- -M memlimit
- Limit for free memory. This is the amount of bytes available as free +
cache. This limit is treated opposite other limits: If the system is above
the limit the program will run, if it is below the limit the program will
stop
memlimit can be postfixed with K, M, G, T, or P which would multiply
the size with 1024, 1048576, 1073741824, or 1099511627776 respectively.
--mem will set both --start-mem and run-mem.
- --noswap
- -N
- No swapping. If the system is swapping both in and out it is a good
indication that the system is memory stressed.
--noswap is over limit if the system is swapping both in and out.
--noswap will set both --start-noswap and
run-noswap.
- -n niceness
- --nice niceness
- Sets niceness. See nice(1).
- -p PID (alpha testing)
- --pid PID (alpha testing)
- Process ID of process to suspend. You can specify multiple process IDs
with multiple -p PID.
- --prg program (alpha testing)
- --program program (alpha testing)
- Name of running program to suspend. You can specify multiple programs with
multiple --prg program.
- --quote
- -q
- Quote the command line. Useful if the command contains chars like *, $,
>, and " that should not be interpreted by the shell.
- --run-io iolimit
- --ri iolimit
- --run-load loadlimit
- --rl loadlimit
- --run-mem memlimit
- --rm memlimit
- Run limit. The running program will be slowed down if the system is above
the limit. See: --io, --load, --mem,
--noswap.
- --sensor sensor program (alpha testing)
- Read sensor. Use sensor program to read a sensor.
This will keep the CPU temperature below 80 deg C on GNU/Linux:
niceload -l 80000 -f 0.001 --sensor 'sort -n /sys/devices/platform/coretemp*/temp*_input' gzip *
This will stop if the disk space < 100000.
niceload -H -l -100000 --sensor "df . | awk '{ print \$4 }'" echo
- --start-io iolimit
- --si iolimit
- --start-load loadlimit
- --sl loadlimit
- --start-mem memlimit
- --sm memlimit
- Start limit. The program will not start until the system is below the
limit. See: --io, --load, --mem,
--noswap.
- --soft
- -S
- Soft limit. niceload will suspend a process for a while and then
let it run for a second thus only slowing down a process while the system
is over one of the given limits. This is the default.
- --suspend SEC
- -s SEC
- Suspend time. Suspend the command this many seconds when the max load
average is reached.
- --recheck SEC
- -t SEC
- Recheck load time. Sleep SEC seconds before checking load again. Default
is 1 second.
- --verbose
- -v
- Verbose. Print some extra output on what is happening. Use -v until
you know what your are doing.
EXAMPLE: See niceload in action¶
In terminal 1 run: top
In terminal 2 run:
niceload -q perl -e '$|=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.
EXAMPLE: Run updatedb¶
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
EXAMPLE: Run rsync¶
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/
EXAMPLE: Ensure enough disk cache¶
Assume the program
foo uses 2 GB files intensively.
foo will run
fast if the files are in disk cache and be slow as a crawl if they are not in
the cache.
To ensure 2 GB are reserved for disk cache run:
niceload --hard --run-mem 2g foo
This will not guarantee that the 2 GB memory will be used for the files for
foo, but it will stop
foo if the memory for disk cache is too
low.
ENVIRONMENT VARIABLES¶
None. In future versions $NICELOAD will be able to contain default settings.
EXIT STATUS¶
Exit status should be the same as the command being run (untested).
REPORTING BUGS¶
Report bugs to <bug-parallel@gnu.org>.
AUTHOR¶
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) 2010,2011,2012 Ole Tange,
http://ole.tange.dk and Free Software
Foundation, Inc.
LICENSE¶
Copyright (C) 2010,2011,2012 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/>.
Documentation license I¶
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.
Documentation license II¶
You are free:
- to Share
- to copy, distribute and transmit the work
- to Remix
- to adapt the work
Under the following conditions:
- Attribution
- You must attribute the work in the manner specified by the author or
licensor (but not in any way that suggests that they endorse you or your
use of the work).
- Share Alike
- If you alter, transform, or build upon this work, you may distribute the
resulting work only under the same, similar or a compatible license.
With the understanding that:
- Waiver
- Any of the above conditions can be waived if you get permission from the
copyright holder.
- Public Domain
- Where the work or any of its elements is in the public domain under
applicable law, that status is in no way affected by the license.
- Other Rights
- In no way are any of the following rights affected by the license:
- •
- Your fair dealing or fair use rights, or other applicable copyright
exceptions and limitations;
- •
- The author's moral rights;
- •
- Rights other persons may have either in the work itself or in how the work
is used, such as publicity or privacy rights.
- Notice
- For any reuse or distribution, you must make clear to others the license
terms of this work.
A copy of the full license is included in the file as cc-by-sa.txt.
DEPENDENCIES¶
GNU
niceload uses Perl, and the Perl modules POSIX, and Getopt::Long.
SEE ALSO¶
parallel(1),
nice(1),
uptime(1)