Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help 
NICELOAD(1)			    parallel			     NICELOAD(1)

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 pro-
     gram] [-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  sys-
     tem  activity) is above a certain limit. When the limit is reached the pro-
     gram 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
     --batterySuspend  if the system is running on battery. Shorthand for: -l -1
	      --sensor 'cat /sys/class/power_supply/BAT0/status  /proc/acpi/bat-
	      tery/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% sat-
	      urated.

	      --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 multi-
	      ply the size with 1024, 1048576, 1073741824, or 1099511627776  re-
	      spectively.

	      --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  pings
	      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  pro-
	      gram  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  pro-
	      grams  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:

		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 un-
	      til 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}un-
     til(($r=time-$^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 re-
     sult 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 set-
     tings.

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) 2010-2026 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 un-
     der  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  FIT-
     NESS 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
     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 distrib-
	      ute the resulting work only under the same, similar or a	compati-
	      ble 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  un-
	      der  applicable  law, that status is in no way affected by the li-
	      cense.

     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  copy-
		right 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  LI-
     CENCES/CC-BY-SA-4.0.txt

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

SEE ALSO
     parallel(1), nice(1), uptime(1)

20260122			   2026-01-31			     NICELOAD(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=niceload&sektion=1&manpath=FreeBSD+Ports+15.1.quarterly>

home | help