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CPUSET(1)		  BSD General Commands Manual		     CPUSET(1)

     cpuset -- configure processor sets

     cpuset [-l	cpu-list] [-n policy:domain-list] [-s setid] cmd ...
     cpuset [-l	cpu-list] [-n policy:domain-list] [-s setid] -p	pid
     cpuset [-c] [-l cpu-list] [-n policy:domain-list] -C -p pid
     cpuset [-c] [-l cpu-list] [-n policy:domain-list]
	    [-j	jail | -p pid |	-t tid | -s setid | -x irq]
     cpuset -g [-cir]
	    [-d	domain | -j jail | -p pid | -t tid | -s	setid |	-x irq]

     The cpuset	command	can be used to assign processor	sets to	processes, run
     commands constrained to a given set or list of processors and memory do-
     mains, and	query information about	processor binding, memory binding and
     policy, sets, and available processors and	memory domains in the system.

     cpuset requires a target to modify	or query.  The target may be specified
     as	a command, process id, thread id, a cpuset id, an irq, a jail, or a
     NUMA domain.  Using -g the	target's set id	or mask	may be queried.	 Using
     -l	or -s the target's CPU mask or set id may be set.  If no target	is
     specified,	cpuset operates	on itself.  Not	all combinations of operations
     and targets are supported.	 For example, you may not set the id of	an ex-
     isting set	or query and launch a command at the same time.

     There are two sets	applicable to each process and one private mask	per
     thread.  Every process in the system belongs to a cpuset.	By default
     processes are started in set 1.  The mask or id may be queried using -c.
     Each thread also has a private mask of CPUs it is allowed to run on that
     must be a subset of the assigned set.  And	finally, there is a root set,
     numbered 0, that is immutable.  This last set is the list of all possible
     CPUs in the system	and is queried using -r.

     Most sets include NUMA memory domain and policy information.  This	can be
     inspected with -g and set with -n.	 This will specify which NUMA domains
     are visible to the	process	and affect where anonymous memory and file
     pages will	be stored on first access.  Files accessed first by other pro-
     cesses may	specify	conflicting policy.

     When running a command it may join	a set specified	with -s	otherwise a
     new set is	created.  In addition, a mask for the command may be specified
     using -l.	When used in conjunction with -c the mask modifies the sup-
     plied or created set rather than the private mask for the thread.

     The options are as	follows:

     -C		  Create a new cpuset and assign the target process to that

     -c		  The requested	operation should reference the cpuset avail-
		  able via the target specifier.

     -d	domain	  Specifies a NUMA domain id as	the target of the operation.
		  This can only	be used	to query the cpus visible in each num-
		  berd domain.

     -g		  Causes cpuset	to print either	a list of valid	CPUs or, using
		  -i, the id of	the target.

     -i		  When used with the -g	option print the id rather than	the
		  valid	mask of	the target.

     -j	jail	  Specifies a jail id or name as the target of the operation.

     -l	cpu-list  Specifies a list of CPUs to apply to a target.  Specifica-
		  tion may include numbers separated by	'-' for	ranges and
		  commas separating individual numbers.	 A special list	of
		  "all"	may be specified in which case the list	includes all
		  CPUs from the	root set.

     -n	policy:domain-list
		  Specifies a list of domains and allocation policy to apply
		  to a target.	Ranges may be specified	as in -l.  Valid poli-
		  cies include first-touch (ft), round-robin (rr), prefer and
		  interleave (il).  First-touch	allocates on the local domain
		  when memory is available.  Round-robin alternates between
		  every	possible domain	page at	a time.	 The prefer policy ac-
		  cepts	only a single domain in	the set.  The parent of	the
		  set is consulted if the preferred domain is unavailable.
		  Interleave operates like round-robin with an implementation
		  defined stripe width.	 See domainset(9) for more details on

     -p	pid	  Specifies a pid as the target	of the operation.

     -s	setid	  Specifies a set id as	the target of the operation.

     -r		  The requested	operation should reference the root set	avail-
		  able via the target specifier.

     -t	tid	  Specifies a thread id	as the target of the operation.

     -x	irq	  Specifies an irq as the target of the	operation.

     The cpuset	utility	exits 0	on success, and	>0 if an error occurs.

     Create a new group	with CPUs 0-4 inclusive	and run	/bin/sh	on it:
	   cpuset -c -l	0-4 /bin/sh

     Query the mask of CPUs the	<sh pid> is allowed to run on:
	   cpuset -g -p	<sh pid>

     Restrict /bin/sh to run on	CPUs 0 and 2 while its group is	still allowed
     to	run on CPUs 0-4:
	   cpuset -l 0,2 -p <sh	pid>

     Modify the	cpuset /bin/sh belongs to restricting it to CPUs 0 and 2:
	   cpuset -l 0,2 -c -p <sh pid>

     Modify the	cpuset all threads are in by default to	contain	only the first
     4 CPUs, leaving the rest idle:
	   cpuset -l 0-3 -s 1

     Print the id of the cpuset	/bin/sh	is in:
	   cpuset -g -i	-p <sh pid>

     Move the pid into the specified cpuset setid so it	may be managed with
     other pids	in that	set:
	   cpuset -s <setid> -p	<pid>

     Create a new cpuset that is restricted to CPUs 0 and 2 and	move pid into
     the new set:
	   cpuset -C -c	-l 0,2 -p <pid>

     cpuset(2),	rctl(8)

     The cpuset	command	first appeared in FreeBSD 7.1.

     Jeffrey Roberson <>

BSD				 July 3, 2018				   BSD


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