freebsd/usr.bin/rctl/rctl.8

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.Dd April 14, 2011
.Dt RCTL 8
.Os
.Sh NAME
.Nm rctl
.Nd display and update resource limits database
.Sh SYNOPSIS
.Nm
.Op Fl h
.Op Fl n
.Op Ar filter
.Nm
.Fl a
.Op Ar rule
.Nm
.Op Fl h
.Op Fl n
.Fl l
.Op Ar filter
.Nm
.Fl r
.Op Ar filter
.Nm
.Op Fl h
.Fl u
.Op Ar filter
.Sh DESCRIPTION
When called without options, the
.Nm
command writes currently defined RCTL rules to standard output.
.Pp
If a
.Ar filter
argument is specified, only rules matching the filter are displayed.
The options are as follows:
.Bl -tag -width indent
.It Fl a Ar rule
Add
.Ar rule
to the RCTL database.
.It Fl l Ar filter
Display rules applicable to the process defined by
.Ar filter .
.It Fl r Ar filter
Remove rules matching
.Ar filter
from the RCTL database.
.It Fl u Ar filter
Display resource usage for a subject (process, user, login class
or jail) matching the
.Ar filter .
.It Fl h
"Human-readable" output.
Use unit suffixes: Byte, Kilobyte, Megabyte,
Gigabyte, Terabyte and Petabyte.
.It Fl n
Display user IDs numerically rather than converting them to a user name.
.Pp
.Sh RULE SYNTAX
Syntax for a rule is subject:subject-id:resource:action=amount/per.
.Pp
Subject defines the kind of entity the rule applies to.
It can be either process, user, login class, or jail.
.Pp
Subject ID identifies the subject.  It can be user name,
numerical user ID, login class name, jail name, or numerical jail ID.
.Pp
Resource identifies the resource the rule controls.
.Pp
Action defines what will happen when a process exceeds the allowed amount.
.Pp
Amount defines how much of the resource a process can use before
the defined action triggers.
.Pp
The per field defines what entity the amount gets accounted for.
For example, rule "loginclass:users:vmem:deny=100M/process" means
that each process of any user belonging to login class "users" may allocate
up to 100MB of virtual memory.
Rule "loginclass:users:vmem:deny=100M/user" would mean that for each
user belonging to the login class "users", the sum of virtual memory allocated
by all the processes of that user will not exceed 100MB.
Rule "loginclass:users:vmem:deny=100M/loginclass" would mean that the sum of
virtual memory allocated by all processes of all users belonging to that login
class will not exceed 100MB.
.Pp
Valid rule has all those fields specified, except for the per, which defaults
to the value of subject.
.Pp
A filter is a rule for which one of more fields other than per is left empty.
For example, a filter that matches every rule could be written as ":::=/",
or, in short, ":".
A filter that matches all the login classes would be "loginclass:".
A filter that matches all defined rules for nproc resource would be
"::nproc".
.Pp
.Sh RESOURCES
.Bl -column -offset 3n "msgqqueued"
.It cpu		CPU time, in milliseconds
.It fsize	maximum file size, in bytes
.It data	data size, in bytes
.It stack	stack size, in bytes
.It core	core dump size, in bytes
.It rss		resident set size, in bytes
.It memlock	locked memory, in bytes
.It nproc	number of processes
.It nofile	file descriptor table size
.It sbsize	memory consumed by socket buffers, in bytes
.It vmem	address space limit, in bytes
.It npts	number of PTYs
.It swap	swap usage, in bytes
.It nthr	number of threads
.It msgqqueued	number of queued SysV messages
.It msgqsize	SysV message queue size, in bytes
.It nmsgq	number of SysV message queues
.It nsem	number of SysV semaphores
.It nsemop	number of SysV semaphores modified in a single semop(2) call
.It nshm	number of SysV shared memory segments
.It shmsize	SysV shared memory size, in bytes
.It wallclock	wallclock time, in milliseconds
.It pctcpu	%cpu time
.El
.Pp
.Sh ACTIONS
.Bl -column -offset 3n "msgqqueued"
.It deny	deny the allocation; not supported for cpu and wallclock
.It log		log a warning to the console
.It devctl	send notification to
.Xr devd 8
.It sig*	e.g. sigterm; send a signal to the offending process
.El
.Pp
See
.Xr signal 3
for a list of supported signals.
.Pp
Not all actions are supported for all resources.
Attempt to add rule with action not supported by a given resouce will result
in error.
.Pp
Note that limiting RSS may kill the machine due to thrashing.
.Pp
.Sh EXIT STATUS
.Ex -std
.Sh EXAMPLES
.Dl rctl -a user:joe:vmem:deny=1g
.Pp
Prevent user "joe" from allocating more than 1GB of virtual memory.
.Pp
.Dl rctl -r :
.Pp
Remove all RCTL rules.
.Pp
.Dl rctl -hu jail:5
.Pp
Display resource usage information for jail with JID 5.
.Pp
.Dl rctl -l process:512
.Pp
Display all the rules applicable to process with PID 512.
.Sh SEE ALSO
.Xr rctl.conf 5 ,
.Xr jailstat 8 ,
.Xr userstat 8
.Sh HISTORY
The
.Nm
command appeared in
.Fx 9.0.
.Sh AUTHORS
.An -nosplit
The
.Nm
command was written by
.An Edward Tomasz Napierala Aq trasz@FreeBSD.org .