RENICE(1)RENICE(1)NAMErenice - alter priority of running processes
SYNOPSISrenice [-n increment] [-i idtype] ID...
renice [-n increment] [-g | -p | -u] ID...
renice priority [-p] pid... [-g gid]... [-p pid]...
[-u user]...
renice priority -g gid... [-g gid]... [-p pid]...
[-u user]...
renice priority -u user... [-g gid]... [-p pid]...
[-u user]...
DESCRIPTION
The renice command alters the scheduling priority of one or more run‐
ning processes. By default, the processes to be affected are specified
by their process IDs.
If the first operand is a number within the valid range of priorities
(−20 to 20), renice will treat it as a priority (as in all but the
first synopsis form). Otherwise, renice will treat it as an ID (as in
the first synopsis form).
Altering Process Priority
Users other than the privileged user may only alter the priority of
processes they own, and can only monotonically increase their "nice
value" within the range 0 to 19. This prevents overriding administra‐
tive fiats. The privileged user may alter the priority of any process
and set the priority to any value in the range −20 to 19. Useful prior‐
ities are: 19 (the affected processes will run only when nothing else
in the system wants to); 0 (the "base" scheduling priority),; and any
negative value (to make things go very fast). 20 is an acceptable nice
value, but will be rounded down to 19.
OPTIONSrenice supports the following option features:
o The first operand, priority, must precede the options and
can have the appearance of a multi-digit option.
o The -g, -p, and -u options can each take multiple option-
arguments.
o The pid option-argument can be used without its -p option.
o The -i option can be used to specify the ID type for the ID
list. This is preferred in specifying ID type over the use
of the -g | -p | -u syntax, which is now obsolete. See
NOTES.
The following options are supported:
-g
Interprets all operands or just the gid arguments as
unsigned decimal integer process group IDs.
-i
This option, together with the ID list arguments, spec‐
ifies a class of processes to which the renice command
is to apply. The interpretation of the ID list depends
on the value of idtype. The valid idtype arguments are:
pid, pgid, uid, gid, sid, taskid, projid, and zoneid.
-n increment
Specifies how the system scheduling priority of the
specified process or processes is to be adjusted. The
increment option-argument is a positive or negative
decimal integer that will be used to modify the system
scheduling priority of the specified process or pro‐
cesses. Positive increment values cause a lower system
scheduling priority. Negative increment values may
require appropriate privileges and will cause a higher
system scheduling priority.
-p
Interprets all operands or just the pid arguments as
unsigned decimal integer process IDs. The -p option is
the default if no options are specified.
-u
Interprets all operands or just the user argument as
users. If a user exists with a user name equal to the
operand, then the user ID of that user will be used in
further processing. Otherwise, if the operand repre‐
sents an unsigned decimal integer, it will be used as
the numeric user ID of the user.
OPERANDS
The following operands are supported:
ID
A process ID, process group ID, or user name/user ID,
depending on the option selected.
priority
The value specified is taken as the actual system schedul‐
ing priority, rather than as an increment to the existing
system scheduling priority. Specifying a scheduling prior‐
ity higher than that of the existing process may require
appropriate privileges.
EXAMPLES
Example 1 Adjusting the scheduling priority of process IDs
Adjust the system scheduling priority so that process IDs 987 and 32
would have a lower scheduling priority:
example% renice-n 5 -p 987 32
Example 2 Adjusting the scheduling priority of group IDs
Adjust the system scheduling priority so that group IDs 324 and 76
would have a higher scheduling priority, if the user has the appropri‐
ate privileges to do so:
example% renice-n -4 -g 324 76
Example 3 Adjusting the scheduling priority of a user ID and user name
Adjust the system scheduling priority so that numeric user ID 8 and
user sas would have a lower scheduling priority:
example% renice-n 4 -u 8 sas
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables
that affect the execution of renice: LANG, LC_ALL, LC_CTYPE, LC_MES‐
SAGES, and NLSPATH.
EXIT STATUS
The following exit values are returned:
0
Successful completion.
>0
An error occurred.
FILES
/etc/passwd
map user names to user IDs
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Interface Stability │ Standard │
└────────────────────┴─────────────────┘
SEE ALSOnice(1), passwd(1), priocntl(1), attributes(5), environ(5), stan‐
dards(5)NOTES
The renice syntax
renice [-n increment] [-i idtype] ID ...
is preferred over the old syntax
renice [-n increment] [-g | -p| -u] ID ...
which is now obsolete.
If you make the priority very negative, then the process cannot be
interrupted.
To regain control you must make the priority greater than 0.
Users other than the privileged user cannot increase scheduling priori‐
ties of their own processes, even if they were the ones that decreased
the priorities in the first place.
The priocntl command subsumes the function of renice.
Jan 9, 2004 RENICE(1)
