renice(1) renice(1)
NAME
renice - alter the scheduling priority of running processes
SYNOPSIS
renice[ -n increment][ -g| -p| -u] ID...
DESCRIPTION
The renice command alters the scheduling priority of one or more run-
ning processes. The relevant processes are usually specified using
their process IDs. If a process group is specified, (see option -g),
the request applies to all the processes in the process group.
The scheduling priority limit values are implementation-dependent. If
the requested increment value raises or lowers the priority of the
executed process over the limit value, the limit whose value was
exceed is used.
If the renice command is executed with the -u option, the request is
valid for all processes whose effective user ID corresponds with that
of the specified user.
Regardless of the options set or other factors, renice only alters the
scheduling priority of a process if the user requesting the alteration
has the appropriate privileges for the specified process. If the user
does not have the privileges required to carry out the required
action, the command returns an error status.
To determine if the user has the appropriate privileges, the real user
ID under which renice is running is checked to see if it corresponds
with the real or the effective user ID of the specified process.
OPTIONS
-g renice interprets all operands as process group IDs.
-n increment
Establishes how the scheduling priority of the specified
process(es) should be adjusted. The increment argument is a posi-
tive or negative decimal integer. The scheduling priority of the
specified process(es) is altered according to the increment.
Positive increment values lower the scheduling priority. Negative
increment values require the appropriate privileges and increase
the scheduling priority.
-p renice interprets all operands as process IDs. If no options are
specified, the -p option is used by default.
-u renice interprets all operands as users. If a user exists whose
user name is the same as the operand, the user ID of the user is
used for further processing. Otherwise, if the operand represents
an unsigned integer, this is used as the numeric user ID of the
user.
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renice(1) renice(1)
ID A process ID, process group ID, or a user name/user ID, depending
on the option selected.
ENVIRONMENT VARIABLES
The following environment variables affect execution of the renice
command:
LANG Specifies a default value for the locale variables that are
unset or null. If LANG is unset or null, the corresponding
default value from the locale is used. If the locale con-
tains an invalid setting, the command behaves as if there
were no variables defined.
LCALL If this variable is set, i.e. is not empty, this value
overwrites the values of all other internationalization
variables.
LCCTYPE Governs the interpretation of byte sequences as characters
(e.g. single-byte as opposed to multibyte characters in
arguments).
LCMESSAGES
Governs the format and content of status messages.
NLSPATH Determines the location of message catalogs for the pro-
cessing of LCMESSAGES.
EXIT STATUS
0 Successful completion.
>0 An error occurred.
EXAMPLES
1. The process IDs 987 and 32 are assigned a lower priority:
renice -n 5 -p 987 32
2. If the user has the appropriate privileges, the scheduling priority
can be adjusted to assign the group IDs 324 and 76 a higher priority:
renice -n -4 -g 324 76
3. The numeric user ID 8 and the user sas are assigned a lower prior-
ity:
renice -n 4 -u 8 sas
On common systems, values between 0 and 39 can be selected for nice.
If you are not the system administrator, you can only lower the
scheduling priority of a process using renice, i.e. increase the nice
value. As a non-system administrator you can also partly or completely
reverse the effect of a preceding renice call by specifying a negative
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renice(1) renice(1)
increment as the argument to -n.
SEE ALSO
nice(1), priocntl(1), ps(1).
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