xref: /freebsd/usr.bin/renice/renice.8 (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
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28.Dd October 27, 2020
29.Dt RENICE 8
30.Os
31.Sh NAME
32.Nm renice
33.Nd alter priority of running processes
34.Sh SYNOPSIS
35.Nm
36.Ar priority
37.Op Oo Fl gpu Oc Ar target
38.Nm
39.Fl n Ar increment
40.Op Oo Fl gpu Oc Ar target
41.Sh DESCRIPTION
42The
43.Nm
44utility alters the
45scheduling priority of one or more running processes.
46The following
47.Ar target
48parameters are interpreted as process ID's (the default), process group
49ID's, user ID's or user names.
50The
51.Nm Ns 'ing
52of a process group causes all processes in the process group
53to have their scheduling priority altered.
54The
55.Nm Ns 'ing
56of a user causes all processes owned by the user to have
57their scheduling priority altered.
58.Pp
59The following options are available:
60.Bl -tag -width indent
61.It Fl n
62Instead of changing the specified processes to the given priority,
63interpret the following argument as an increment to be applied to
64the current priority of each process.
65.It Fl g
66Interpret
67.Ar target
68parameters as process group ID's.
69.It Fl p
70Interpret
71.Ar target
72parameters as process ID's (the default).
73.It Fl u
74Interpret
75.Ar target
76parameters as user names or user ID's.
77.El
78.Pp
79Users other than the super-user may only alter the priority of
80processes they own,
81and can only monotonically increase their ``nice value''
82within the range 0 to
83.Dv PRIO_MAX
84(20).
85(This prevents overriding administrative fiats.)
86The super-user
87may alter the priority of any process
88and set the priority to any value in the range
89.Dv PRIO_MIN
90(\-20)
91to
92.Dv PRIO_MAX .
93Useful priorities are:
9420 (the affected processes will run only when nothing else
95in the system wants to),
960 (the ``base'' scheduling priority),
97anything negative (to make things go very fast).
98.Sh FILES
99.Bl -tag -width /etc/passwd -compact
100.It Pa /etc/passwd
101to map user names to user ID's
102.El
103.Sh EXAMPLES
104Change the priority of process ID's 987 and 32, and
105all processes owned by users daemon and root.
106.Pp
107.Dl "renice +1 987 -u daemon root -p 32"
108.Sh SEE ALSO
109.Xr nice 1 ,
110.Xr rtprio 1 ,
111.Xr getpriority 2 ,
112.Xr setpriority 2
113.Sh STANDARDS
114The
115.Nm
116utility conforms to
117.St -p1003.1-2001 .
118.Sh HISTORY
119The
120.Nm
121utility appeared in
122.Bx 4.0 .
123.Sh BUGS
124Non super-users cannot increase scheduling priorities of their own processes,
125even if they were the ones that decreased the priorities in the first place.
126