freebsd-skq/usr.bin/renice/renice.8

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.\"     @(#)renice.8	8.1 (Berkeley) 6/9/93
.\" $FreeBSD$
.\"
.Dd October 27, 2020
.Dt RENICE 8
.Os
.Sh NAME
.Nm renice
.Nd alter priority of running processes
.Sh SYNOPSIS
.Nm
.Ar priority
.Op Oo Fl gpu Oc Ar target
.Nm
.Fl n Ar increment
.Op Oo Fl gpu Oc Ar target
.Sh DESCRIPTION
The
.Nm
utility alters the
scheduling priority of one or more running processes.
The following
.Ar target
parameters are interpreted as process ID's (the default), process group
ID's, user ID's or user names.
The
.Nm Ns 'ing
of a process group causes all processes in the process group
to have their scheduling priority altered.
The
.Nm Ns 'ing
of a user causes all processes owned by the user to have
their scheduling priority altered.
.Pp
The following options are available:
.Bl -tag -width indent
.It Fl n
Instead of changing the specified processes to the given priority,
interpret the following argument as an increment to be applied to
the current priority of each process.
.It Fl g
Interpret
.Ar target
parameters as process group ID's.
.It Fl p
Interpret
.Ar target
parameters as process ID's (the default).
.It Fl u
Interpret
.Ar target
parameters as user names or user ID's.
.El
.Pp
Users other than the super-user may only alter the priority of
processes they own,
and can only monotonically increase their ``nice value''
within the range 0 to
.Dv PRIO_MAX
(20).
(This prevents overriding administrative fiats.)
The super-user
may alter the priority of any process
and set the priority to any value in the range
.Dv PRIO_MIN
(\-20)
to
.Dv PRIO_MAX .
Useful priorities are:
20 (the affected processes will run only when nothing else
in the system wants to),
0 (the ``base'' scheduling priority),
anything negative (to make things go very fast).
.Sh FILES
.Bl -tag -width /etc/passwd -compact
.It Pa /etc/passwd
to map user names to user ID's
.El
.Sh EXAMPLES
Change the priority of process ID's 987 and 32, and
all processes owned by users daemon and root.
.Pp
.Dl "renice +1 987 -u daemon root -p 32"
.Sh SEE ALSO
.Xr nice 1 ,
.Xr rtprio 1 ,
.Xr getpriority 2 ,
.Xr setpriority 2
.Sh STANDARDS
The
.Nm
utility conforms to
.St -p1003.1-2001 .
.Sh HISTORY
The
.Nm
utility appeared in
.Bx 4.0 .
.Sh BUGS
Non super-users cannot increase scheduling priorities of their own processes,
even if they were the ones that decreased the priorities in the first place.