
****
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 ...] | --prg program )


***********
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
*******



- \ **-B**\ 



- \ **--battery**\ 
 
 Suspend if the system is running on battery. Shorthand for:
 -l -1 --sensor 'cat /sys/class/power_supply/BAT0/status
 /proc/acpi/battery/BAT0/state 2>/dev/null | grep -i -q discharging;
 echo $?'
 


- \ **-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**\ .
 


- \ **--net**\ 
 
 Shorthand for \ **--nethops 3**\ .
 


- \ **--nethops**\  \ *h*\ 
 
 Network nice. Pause if the internet connection is overloaded.
 
 \ **niceload**\  finds a router \ *h*\  hops closer to the internet. It
 \ **ping**\ s this every second. If the latency is more than 50% bigger
 than the median, it is regarded as being over the limit.
 
 \ **--nethops**\  can be combined with \ **--hard**\ . Without \ **--hard**\  the
 program may be able to queue up so much traffic that it will take
 longer than the \ **--suspend**\  time to clear it. \ **--hard**\  is useful for
 traffic that does not break by being suspended for a longer time.
 
 \ **--nethops**\  can be combined with a high \ **--suspend**\ . This way a
 program can be allowed to do a bit of traffic now and then. This is
 useful to keep the connection alive.
 


- \ **-n**\  \ *niceness*\ 



- \ **--nice**\  \ *niceness*\ 
 
 Sets niceness. See \ **nice**\ (1).
 


- \ **-p**\  \ *PID*\ [,\ *PID*\ ]



- \ **--pid**\  \ *PID*\ [,\ *PID*\ ]
 
 Process IDs of processes to suspend. You can specify multiple process
 IDs with multiple \ **-p**\  \ *PID*\  or by separating the PIDs with comma.
 


- \ **--prg**\  \ *program*\ 



- \ **--program**\  \ *program*\ 
 
 Name of running program to suspend. You can specify multiple programs
 with multiple \ **--prg**\  \ *program*\ . If no processes with the name
 \ *program*\  is found, \ **niceload**\  with search for substrings containing
 \ *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*\ 
 
 Read sensor. Use \ *sensor program*\  to read a sensor.
 
 This will keep the CPU temperature below 80 deg C on GNU/Linux:
 
 
 .. code-block:: perl
 
    niceload -l 80000 -f 0.001 --sensor 'sort -n /sys/devices/platform/coretemp*/temp*_input' gzip *
 
 
 This will stop if the disk space < 100000.
 
 
 .. code-block:: perl
 
    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) 2005-2010 Ole Tange, http://ole.tange.dk

Copyright (C) 2010-2021 Ole Tange, http://ole.tange.dk and Free
Software Foundation, Inc.


*******
LICENSE
*******


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 LICENSES/GFDL-1.3-or-later.txt.


Documentation license II
========================


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 If you alter, transform, or build upon this work, you may distribute
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************
DEPENDENCIES
************


GNU \ **niceload**\  uses Perl, and the Perl modules POSIX, and
Getopt::Long.


********
SEE ALSO
********


\ **parallel**\ (1), \ **nice**\ (1), \ **uptime**\ (1)

