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cpusetAllocQueueDef(3x)				       cpusetAllocQueueDef(3x)

NAME    [Toc]    [Back]

     cpusetAllocQueueDef - allocate a cpuset_QueueDef_t	structure

SYNOPSIS    [Toc]    [Back]

     #include <cpuset.h>

     cpuset_QueueDef_t *cpusetAllocQueueDef(int	count)

DESCRIPTION    [Toc]    [Back]

     The cpusetAllocQueueDef function is used to allocate memory for a
     cpuset_QueueDef_t structure.  This	memory can then	be released using the
     function cpusetFreeQueueDef(3x).

     The count argument	indicates the number of	CPUs that will be assigned to
     the cpuset	definition structure.  The cpuset_QueueDef_t structure is
     defined as	follows:

	       typedef struct {
		   int		      flags;
		   char		      *permfile;
		   cpuset_CPUList_t   *cpu;
	       } cpuset_QueueDef_t;

     The flags member is used to specify various control options for the
     cpuset queue.  It is formed by OR-ing together zero or more of the
     following values:

	    Defines a cpuset to	be restricted.	Only threads attached to the
	    cpuset queue (descendents of an attached thread inherit the
	    attachement) may execute on	the CPUs contained in the cpuset.

	    Threads assigned to	the cpuset will	attempt	to assign memory only
	    from nodes within the cpuset.  Assignment of memory	from outside
	    the	cpuset will occur only if no free memory is available from
	    within the cpuset.	No restrictions	are made on memory assignment
	    to threads running outside the cpuset.

	    Threads assigned to	the cpuset will	attempt	to assign memory only
	    from nodes within the cpuset.  Assignment of memory	from outside
	    the	cpuset will occur only if no free memory is available from
	    within the cpuset.	Threads	not assigned to	the cpuset will	not
	    use	memory from within the cpuset unless no	memory outside the
	    cpuset is available.  If, at the time a cpuset is created, memory
	    is already assigned	to threads that	are already running, no
	    attempt will be made to explicitly move this memory.  If page
	    migration is enabled, the pages will be migrated when the system
	    detects that most references to the	pages are non-local.

									Page 1

cpusetAllocQueueDef(3x)				       cpusetAllocQueueDef(3x)

	    The	kernel should attempt to avoid allocating memory from nodes
	    contained in this cpuset. If kernel	memory requests	cannot be
	    satisfied from outside this	cpuset,	this option will be ignored
	    and	allocations will occur from within the cpuset. (This avoidance
	    currently extends only to keeping buffer cache away	from the
	    protected nodes.)

	    The	kernel will limit all memory allocations to nodes that are
	    contained in this cpuset. If memory	requests cannot	be satisfied,
	    the	allocating process will	sleep until memory is available. The
	    process will be killed if no more memory can be allocated. See
	    policies below.

	    Requires MEMORY_MANDATORY. This is the default policy if no	policy
	    is specified. This policy will cause the kernel to page user pages
	    to the swap	file (see swap(1M)) to free physical memory on the
	    nodes contained in this cpuset. If swap space is exhausted,	the
	    process will be killed.

	    Requires MEMORY_MANDATORY. The kernel will attempt to free as much
	    space as possible from kernel heaps, but will not page user	pages
	    to the swap	file.  If all physical memory on the nodes contained
	    in this cpuset are exhausted, the process will be killed.

     The permfile member is the	name of	the file that defines the access
     permissions for the cpuset	queue.	The file permissions of	filename
     referenced	by permfile define access to the cpuset.  Every	time
     permissions need to be checked, the current permissions of	this file are
     used.  Thus, it is	possible to change the access to a particular cpuset
     without having to tear it down and	recreate it, simply by changing	the
     access permissions.  Read access to the permfile allows a user to
     retrieve information about	a cpuset, while	execute	permission allows the
     user to attach a process to the cpuset.

     The cpu member is a pointer to a cpuset_CPUList_t structure.  The memory
     for the cpuset_CPUList_t structure	is allocated and released when the
     cpuset_QueueDef_t structure is allocated and released (see
     cpusetFreeQueueDef(3x)). The cpuset_CPUList_t structure contains the list
     of	CPUs assigned to the cpuset.  The cpuset_CPUList_t structure (defind
     in	<cpuset.h>) is defined as follows:

	       typedef struct {
		   int	  count;
		   int	  *list;
	       } cpuset_CPUList_t;

									Page 2

cpusetAllocQueueDef(3x)				       cpusetAllocQueueDef(3x)

     The count member defines the number of CPUs contained in the list.

     The list member is	the pointer to the list	(an allocated array) of	the
     CPU IDs.  The memory for the list array is	allocated and released when
     the cpuset_CPUList_t structure is allocated and released.	The size of
     the list is determined by the count argument passed into the function

EXAMPLES    [Toc]    [Back]

     This example creates a cpuset queue using cpusetCreate(3x)	and provides
     an	example	of how cpusetAllocQueueDef might be used.  The cpuset created
     will have access controlled by the	file /usr/tmp/mypermfile; it will
     contain CPU IDs 4,	8, and 12; and it will be CPU exclusive	and memory

	       cpuset_QueueDef_t *qdef;
	       char		 *qname	= "myqueue";

	       /* Alloc	queue def for 3	CPU IDs	*/
	       qdef = cpusetAllocQueueDef(3);
	       if (!qdef) {

	       /* Define attributes of the cpuset */
	       qdef->flags = CPUSET_CPU_EXCLUSIVE
	       qdef->permfile =	"/usr/tmp/mypermfile"
	       qdef->cpu->count	= 3;
	       qdef->cpu->list[0] = 4;
	       qdef->cpu->list[1] = 8;
	       qdef->cpu->list[2] = 12;

	       /* Request that the cpuset be created */
	       if (!cpusetCreate(qname,	qdef)) {

NOTES    [Toc]    [Back]

     cpusetAllocQueueDef is found in the library "libcpuset.so", and will be
     loaded if the option -lcpuset is used with	cc(1) or ld(1).

SEE ALSO    [Toc]    [Back]

     cpuset(1),	cpusetAllocQueueDef(3x), cpusetFreeQueueDef(3x).  cpuset(5).

									Page 3

cpusetAllocQueueDef(3x)				       cpusetAllocQueueDef(3x)

     If	successful, cpusetAllocQueueDef	returns	a pointer to a
     cpuset_QueueDef_t structure.  If cpusetAllocQueueDef fails, it returns
     NULL and errno is set to indicate the error.  The possible	errno values
     include those returned by sbrk(2) and the following:

     EINVAL    [Toc]    [Back]
	  Invalid argument was supplied.  The user must	supply a value greater
	  than or equal	to 0.

									PPPPaaaaggggeeee 4444
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