xref: /freebsd/usr.bin/protect/protect.1 (revision f677a9e2672665f4eb3dd4111c07ee8f1f954262)
1.\" Copyright (c) 2013 Advanced Computing Technologies LLC
2.\" Written by: John H. Baldwin <jhb@FreeBSD.org>
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26.\" $FreeBSD$
27.\"
28.Dd September 19, 2013
29.Dt PROTECT 1
30.Os
31.Sh NAME
32.Nm protect
33.Nd "protect processes from being killed when swap space is exhausted"
34.Sh SYNOPSIS
35.Nm
36.Op Fl i
37.Ar command
38.Nm
39.Op Fl cdi
40.Fl g Ar pgrp | Fl p Ar pid
41.Sh DESCRIPTION
42The
43.Nm
44command is used to mark processes as protected.
45The kernel does not kill protected processes when swap space is exhausted.
46Note that this protected state is not inherited by child processes by default.
47.Pp
48The options are:
49.Bl -tag -width XXXXXXXXXX
50.It Fl c
51Remove protection from the specified processes.
52.It Fl d
53Apply the operation to all current children of the specified processes.
54.It Fl i
55Apply the operation to all future children of the specified processes.
56.It Fl g Ar pgrp
57Apply the operation to all processes in the specified process group.
58.It Fl p Ar pid
59Apply the operation to the specified process.
60.It Ar command
61Execute
62.Ar command
63as a protected process.
64.El
65.Pp
66Note that only one of the
67.Fl p
68or
69.Fl g
70flags may be specified when adjusting the state of existing processes.
71.Sh EXIT STATUS
72.Ex -std
73.Sh EXAMPLES
74Mark the Xorg server as protected:
75.Pp
76.Dl "pgrep Xorg | xargs protect -p"
77.Pp
78Protect all ssh sessions and their child processes:
79.Pp
80.Dl "pgrep sshd | xargs protect -dip"
81.Pp
82Remove protection from all current and future processes:
83.Pp
84.Dl "protect -cdi -p 1"
85.Sh SEE ALSO
86.Xr procctl 2
87.Sh BUGS
88If you protect a runaway process that allocates all memory the system will
89deadlock.
90