xref: /freebsd/usr.bin/rctl/rctl.8 (revision 4f8f43b06ed07e96a250855488cc531799d5b78f)
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25.Dd February 26, 2018
26.Dt RCTL 8
27.Os
28.Sh NAME
29.Nm rctl
30.Nd display and update resource limits database
31.Sh SYNOPSIS
32.Nm
33.Op Fl h
34.Op Fl n
35.Op Ar filter Ar ...
36.Nm
37.Fl a
38.Ar rule Ar ...
39.Nm
40.Fl l
41.Op Fl h
42.Op Fl n
43.Ar filter Ar ...
44.Nm
45.Fl r
46.Ar filter Ar ...
47.Nm
48.Fl u
49.Op Fl h
50.Ar filter Ar ...
51.Sh DESCRIPTION
52When called without options, the
53.Nm
54command writes currently defined RCTL rules to standard output.
55.Pp
56If a
57.Ar filter
58argument is specified, only rules matching the filter are displayed.
59The options are as follows:
60.Bl -tag -width indent
61.It Fl a Ar rule
62Add
63.Ar rule
64to the RCTL database.
65.It Fl l Ar filter
66Display rules applicable to the process defined by
67.Ar filter .
68Note that this is different from showing the rules when called without
69any options, as it shows not just the rules with subject equal to that
70of process, but also rules for the user, jail, and login class applicable
71to the process.
72.It Fl r Ar filter
73Remove rules matching
74.Ar filter
75from the RCTL database.
76.It Fl u Ar filter
77Display resource utilization for a subject
78.Po
79.Sy process ,
80.Sy user ,
81.Sy loginclass
82or
83.Sy jail
84.Pc
85matching the
86.Ar filter .
87.It Fl h
88"Human-readable" output.
89Use unit suffixes: Byte, Kilobyte, Megabyte,
90Gigabyte, Terabyte and Petabyte.
91.It Fl n
92Display user IDs numerically rather than converting them to a user name.
93.El
94.Pp
95Modifying rules affects all currently running and future processes matching
96the rule.
97.Sh RULE SYNTAX
98Syntax for a rule is subject:subject-id:resource:action=amount/per.
99.Pp
100.Bl -tag -width "subject-id" -compact -offset indent
101.It subject
102defines the kind of entity the rule applies to.
103It can be either
104.Sy process ,
105.Sy user ,
106.Sy loginclass ,
107or
108.Sy jail .
109.It subject-id
110identifies the
111.Em subject .
112It can be a process ID, user name, numerical user ID, login class name from
113.Xr login.conf 5 ,
114or jail name.
115.It resource
116identifies the resource the rule controls.
117See the
118.Sx RESOURCES
119section below for details.
120.It action
121defines what will happen when a process exceeds the allowed
122.Em amount .
123See the
124.Sx ACTIONS
125section below for details.
126.It amount
127defines how much of the resource a process can use before
128the defined
129.Em action
130triggers.
131Resources which limit bytes may use prefixes from
132.Xr expand_number 3 .
133.It per
134defines what entity the
135.Em amount
136gets accounted for.
137For example, rule "loginclass:users:vmemoryuse:deny=100M/process" means
138that each process of any user belonging to login class "users" may allocate
139up to 100MB of virtual memory.
140Rule "loginclass:users:vmemoryuse:deny=100M/user" would mean that for each
141user belonging to the login class "users", the sum of virtual memory allocated
142by all the processes of that user will not exceed 100MB.
143Rule "loginclass:users:vmemoryuse:deny=100M/loginclass" would mean that the sum of
144virtual memory allocated by all processes of all users belonging to that login
145class will not exceed 100MB.
146.El
147.Pp
148A valid rule has all those fields specified, except for
149.Em per ,
150which defaults
151to the value of
152.Em subject .
153.Pp
154A filter is a rule for which one of more fields other than
155.Em per
156is left empty.
157For example, a filter that matches every rule could be written as ":::=/",
158or, in short, ":".
159A filter that matches all the login classes would be "loginclass:".
160A filter that matches all defined rules for
161.Sy maxproc
162resource would be
163"::maxproc".
164.Sh SUBJECTS
165.Bl -column -offset 3n "pseudoterminals" ".Sy username or numerical User ID"
166.It Sy process Ta numerical Process ID
167.It Sy user Ta user name or numerical User ID
168.It Sy loginclass Ta login class from
169.Xr login.conf 5
170.It Sy jail Ta jail name
171.El
172.Sh RESOURCES
173.Bl -column -offset 3n "pseudoterminals"
174.It Sy cputime Ta "CPU time, in seconds"
175.It Sy datasize Ta "data size, in bytes"
176.It Sy stacksize Ta "stack size, in bytes"
177.It Sy coredumpsize Ta "core dump size, in bytes"
178.It Sy memoryuse Ta "resident set size, in bytes"
179.It Sy memorylocked Ta "locked memory, in bytes"
180.It Sy maxproc Ta "number of processes"
181.It Sy openfiles Ta "file descriptor table size"
182.It Sy vmemoryuse Ta "address space limit, in bytes"
183.It Sy pseudoterminals Ta "number of PTYs"
184.It Sy swapuse Ta "swap space that may be reserved or used, in bytes"
185.It Sy nthr Ta "number of threads"
186.It Sy msgqqueued Ta "number of queued SysV messages"
187.It Sy msgqsize Ta "SysV message queue size, in bytes"
188.It Sy nmsgq Ta "number of SysV message queues"
189.It Sy nsem Ta "number of SysV semaphores"
190.It Sy nsemop Ta "number of SysV semaphores modified in a single semop(2) call"
191.It Sy nshm Ta "number of SysV shared memory segments"
192.It Sy shmsize Ta "SysV shared memory size, in bytes"
193.It Sy wallclock Ta "wallclock time, in seconds"
194.It Sy pcpu Ta "%CPU, in percents of a single CPU core"
195.It Sy readbps Ta "filesystem reads, in bytes per second"
196.It Sy writebps Ta "filesystem writes, in bytes per second"
197.It Sy readiops Ta "filesystem reads, in operations per second"
198.It Sy writeiops Ta "filesystem writes, in operations per second"
199.El
200.Sh ACTIONS
201.Bl -column -offset 3n "pseudoterminals"
202.It Sy deny Ta deny the allocation; not supported for
203.Sy cputime ,
204.Sy wallclock ,
205.Sy readbps ,
206.Sy writebps ,
207.Sy readiops ,
208and
209.Sy writeiops
210.It Sy log Ta "log a warning to the console"
211.It Sy devctl Ta "send notification to"
212.Xr devd 8
213using
214.Sy system
215= "RCTL",
216.Sy subsystem
217= "rule",
218.Sy type
219= "matched"
220.It sig*	e.g.
221.Sy sigterm ;
222send a signal to the offending process.
223See
224.Xr signal 3
225for a list of supported signals
226.It Sy throttle Ta "slow down process execution"; only supported for
227.Sy readbps ,
228.Sy writebps ,
229.Sy readiops ,
230and
231.Sy writeiops .
232.El
233.Pp
234Not all actions are supported for all resources.
235Attempting to add a rule with an action not supported by a given resource will
236result in error.
237.Sh EXIT STATUS
238.Ex -std
239.Sh EXAMPLES
240Prevent user "joe" from allocating more than 1GB of virtual memory:
241.Dl Nm Fl a Ar user:joe:vmemoryuse:deny=1g
242.Pp
243Remove all RCTL rules:
244.Dl Nm Fl r Ar \&:
245.Pp
246Display resource utilization information for jail named "www":
247.Dl Nm Fl hu Ar jail:www
248.Pp
249Display all the rules applicable to process with PID 512:
250.Dl Nm Fl l Ar process:512
251.Pp
252Display all rules:
253.Dl Nm
254.Pp
255Display all rules matching user "joe":
256.Dl Nm Ar user:joe
257.Pp
258Display all rules matching login classes:
259.Dl Nm Ar loginclass:
260.Sh SEE ALSO
261.Xr cpuset 1 ,
262.Xr rctl 4 ,
263.Xr rctl.conf 5
264.Sh HISTORY
265The
266.Nm
267command appeared in
268.Fx 9.0 .
269.Sh AUTHORS
270.An -nosplit
271The
272.Nm
273was developed by
274.An Edward Tomasz Napierala Aq Mt trasz@FreeBSD.org
275under sponsorship from the FreeBSD Foundation.
276.Sh BUGS
277Limiting
278.Sy memoryuse
279may kill the machine due to thrashing.
280.Pp
281The
282.Sy readiops
283and
284.Sy writeiops
285counters are only approximations.
286Like
287.Sy readbps
288and
289.Sy writebps ,
290they are calculated in the filesystem layer, where it is difficult
291or even impossible to observe actual disk device operations.
292.Pp
293The
294.Sy writebps
295and
296.Sy writeiops
297resources generally account for writes to the filesystem cache,
298not to actual devices.
299