processor_sets(4) [osf1 man page]

processor_sets(4)					     Kernel Interfaces Manual						 processor_sets(4)

NAME

       processor_sets - Collections of processors

DESCRIPTION

       A  processor  set  is  a collection of processors.  When a processor set is first created, it does not contain any processors.  You can add
       processors to a processor set, remove processors from a processor set, and also destroy the processor set.  In  addition,  you  can  assign
       specific processes to a processor set.

       When  the  system  is  booted, all its processors are assigned to the default processor set.  Each processor in a system can be a member of
       only one processor set at one time.

       In addition, when you create a process, it is assigned to a processor set.  Unless you indicate a specific  processor  set,  a  process	is
       assigned  to  the  default  processor  set.   A process can execute only on an processor that is included in the processor set to which the
       process is assigned.  If you assign a process to an empty processor set, it will not execute until a processor is assigned to the processor
       set or until the process is assigned to another processor set.

       Use the pset_create command or the create_pset function to create a processor set.  When you first create a processor set, it does not con-
       tain any processors.

       Use the pset_assign_cpu command or the assign_cpu_to_pset function to assign processors to a specific processor set.   When  you  assign  a
       processor to a specific processor set, the processor is removed from its current processor set.

       Use the pset_destroy command or the destroy_pset function to destroy a processor set.   Processors that belong to a destroyed processor set
       are assigned to the default processor set.

       Use the pset_assign_pid command or the assign_pid_to_pset function to assign a process to a specific processor set.  In addition,  you  can
       request	that a process has exclusive access to a processor set.  If a process has exclusive access to a processor set, no other process is
       able to use that processor set.	If a process has exclusive access to a processor set, that access will be cleared automatically  when  the
       process exits.  Note that if a process is already assigned to a processor set, a request for exclusive access to that processor set will be
       denied.

       Use the pset_info command to display the status of each processor set on the system as well as the status of each processor.

       You must be root to create and destroy processor sets and to assign a processor to a processor set.  Processor set creation and destruction
       and processor assignments to processor sets are logged in the /var/adm/wtmp file.

FILES

       /var/adm/wtmp

RELATED INFORMATION

       Commands: pset_create(1), pset_destroy(1), pset_info(1), pset_assign_pid(1), pset_assign_cpu(1), runon(1), psrinfo(1), psradm(8)

       Functions: assign_pid_to_pset(3), assign_cpu_to_pset(3), create_pset(3), destroy_pset(3) delim off

																 processor_sets(4)

pset_destroy(2) 						System Calls Manual						   pset_destroy(2)

NAME

       pset_destroy() - destroy a processor set

SYNOPSIS

DESCRIPTION

       The  function destroys the processor set pset, releasing all constituent processors and processes by default.  The processors and processes
       are reassigned to the system default processor set.  Once destroyed, the pset identifier becomes available for new processor sets that  may
       be created in the future.

       The  behavior when attempting to destroy a non-empty processor set may be controlled by changing the attribute of the processor set through
       the function.  See pset_getattr(2).  The following values are supported for the attribute:

       Reassign all processors in the
		      pset to the system default processor set.  Migrate all threads and processes bound to the pset to the system default proces-
		      sor set.

       Make the request fail with
		      if there are any threads or processes bound to pset or if there are processors assigned to the pset.

       Make the request fail with
		      only  if	there are active threads or processes bound to the processor set.  Otherwise, perform the operation by reassigning
		      the processors in the pset to the system default processor set.

       If the threads and processes being reassigned to the default processor set have some binding to a processor or a  locality  domain  in  the
       pset being destroyed, their binding is reassigned to a processor or a locality domain in the system default processor set.

       A user with the privilege or a user with WRITE permission on the pset may destroy the processor set pset.  The system default processor set
       may never be destroyed.

   Security Restrictions
       Some or all of the actions associated with this system call require the privilege.  Processes owned by the superuser have  this	privilege.
       Processes  owned  by  other users may have this privilege, depending on system configuration.  See privileges(5) for more information about
       privileged access on systems that support fine-grained privileges.

   Note on Logical Processor and Hyper-Threading Feature
       On systems with the Hyper-Threading (HT) feature enabled at the firmware level, each processor core may have more than one hyper-thread per
       physical processor core.  Each hyper-thread is represented to the operating system and applications as a logical processor (LCPU).

       Due  to	the  processor set contract, which specifies that applications bound to a processor set have complete and exclusive control of all
       processor cores within that processor set, migration of processors between two processor sets is done at the processor core granularity.

       For destruction of a processor set migrates a set of processor cores to the default processor set.  Depending on the source  processor  set
       and the default processor set's the number of logical processors visible to the users and applications may change.

EXAMPLES

       Destroy a processor set with the processor set ID of pset.

RETURN VALUE

       returns zero on successful completion.  Otherwise, -1 is returned and is set to indicate the error.

ERRORS

       fails if one or more of the following is true:

       The attribute value for the processor set does not allow
		    deletion of a non-empty processor set.

       The operation was interrupted.

       pset	    is not a valid processor set.

       The processor set functionality is not supported by the
		    underlying HP-UX version.

       The user does not have necessary permissions to destroy a
		    processor set or the system default processor set was specified.

SEE ALSO

       psrset(1M), pset_assign(2), pset_bind(2), pset_create(2), pset_ctl(2), pset_getattr(2), privgrp(4), privileges(5).

																   pset_destroy(2)