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rctl(8) [freebsd man page]

RCTL(8) 						    BSD System Manager's Manual 						   RCTL(8)

rctl -- display and update resource limits database SYNOPSIS
rctl [-h] [-n] [filter] rctl -a [rule] rctl -l [-h] [-n] [filter] rctl -r [filter] rctl -u [-h] [filter] rctl requires the kernel to be compiled with: options RACCT options RCTL DESCRIPTION
When called without options, the rctl command writes currently defined RCTL rules to standard output. If a filter argument is specified, only rules matching the filter are displayed. The options are as follows: -a rule Add rule to the RCTL database. -l filter Display rules applicable to the process defined by filter. Note that this is different from showing the rules when called without any options, as it shows not just the rules with subject equal to that of process, but also rules for the user, jail, and login class applicable to the process. -r filter Remove rules matching filter from the RCTL database. -u filter Display resource usage for a subject (process, user, loginclass or jail) matching the filter. -h "Human-readable" output. Use unit suffixes: Byte, Kilobyte, Megabyte, Gigabyte, Terabyte and Petabyte. -n Display user IDs numerically rather than converting them to a user name. Modifying rules affects all currently running and future processes matching the rule. RULE SYNTAX
Syntax for a rule is subject:subject-id:resource:action=amount/per. subject defines the kind of entity the rule applies to. It can be either process, user, loginclass, or jail. subject-id identifies the subject. It can be a process ID, user name, numerical user ID, login class name from login.conf(5), or jail name. resource identifies the resource the rule controls. See the RESOURCES section below for details. action defines what will happen when a process exceeds the allowed amount. See the ACTIONS section below for details. amount defines how much of the resource a process can use before the defined action triggers. Resources which limit bytes may use prefixes from expand_number(3). per 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 "login- class: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/login- class" would mean that the sum of virtual memory allocated by all processes of all users belonging to that login class will not exceed 100MB. A valid rule has all those fields specified, except for per, which defaults to the value of subject. 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 maxproc resource would be "::maxproc". SUBJECTS
subject subject-id process numerical Process ID user user name or numerical User ID loginclass login class from login.conf(5) jail jail name RESOURCES
resource cputime CPU time, in seconds datasize data size, in bytes stacksize stack size, in bytes coredumpsize core dump size, in bytes memoryuse resident set size, in bytes memorylocked locked memory, in bytes maxproc number of processes openfiles file descriptor table size vmemoryuse address space limit, in bytes pseudoterminals number of PTYs swapuse swap usage, in bytes nthr number of threads msgqqueued number of queued SysV messages msgqsize SysV message queue size, in bytes nmsgq number of SysV message queues nsem number of SysV semaphores nsemop number of SysV semaphores modified in a single semop(2) call nshm number of SysV shared memory segments shmsize SysV shared memory size, in bytes wallclock wallclock time, in seconds pcpu %CPU, in percents of a single CPU core ACTIONS
action deny deny the allocation; not supported for cputime and wallclock log log a warning to the console devctl send notification to devd(8) using system = "RCTL", subsystem = "rule", type = "matched" sig* e.g. sigterm; send a signal to the offending process. See signal(3) for a list of supported signals Not all actions are supported for all resources. Attempting to add a rule with an action not supported by a given resource will result in error. EXIT STATUS
The rctl utility exits 0 on success, and >0 if an error occurs. EXAMPLES
Prevent user "joe" from allocating more than 1GB of virtual memory: rctl -a user:joe:vmemoryuse:deny=1g Remove all RCTL rules: rctl -r : Display resource usage information for jail named "www": rctl -hu jail:www Display all the rules applicable to process with PID 512: rctl -l process:512 Display all rules: rctl Display all rules matching user "joe": rctl user:joe Display all rules matching login classes: rctl loginclass: SEE ALSO
rctl.conf(5) HISTORY
The rctl command appeared in FreeBSD 9.0. AUTHORS
The rctl was developed by Edward Tomasz Napierala <> under sponsorship from the FreeBSD Foundation. BUGS
Limiting memoryuse may kill the machine due to thrashing. BSD
September 11, 2014 BSD
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