pset_assign(2)                                               pset_assign(2)




 NAME    [Toc]    [Back]
      pset_assign - change processor set assignment

 SYNOPSIS    [Toc]    [Back]
      #include <sys/pset.h>

      int pset_assign(
           psetid_t  pset,
           spu_t     spu,
           psetid_t  *opset);

 DESCRIPTION    [Toc]    [Back]
      The pset_assign() function assigns the processor spu to the processor
      set pset, removing the processor spu from its current processor set.
      A processor may not belong to more than one processor set at any given
      time. If opset is not NULL, it contains the processor set ID of the
      previously assigned processor set upon successful operation.

      A superuser, a PRIV_PSET privilege user, or a user with WRITE
      permissions on the processor sets may change the processor set
      assignment for a processor using pset_assign() function. A user other
      than superuser or without PRIV_PSET privileges must have WRITE
      permissions in both processor sets to make the processor reassignment,
      unless the target processor set is the system default processor set.
      That is, only a superuser or a PRIV_PSET privilege user may move a
      processor out of the system default processor set.

      Currently, processor 0 cannot be reassigned to another processor set
      from the system default processor set. The system default processor
      set is never empty.

      If pset is PS_DEFAULT or PS_NONE, the processor spu is assigned to the
      system default processor set.

      If pset is PS_QUERY, the processor's assignment is not changed, but
      the current processor set ID of processor spu is returned in opset. No
      superuser access or WRITE permission is needed for PS_QUERY operation.

      If there are threads or processes with binding to the processor spu
      (in its old processor set), the binding of affected threads and
      processes is changed to another processor in that processor set. If
      spu is the last processor in the locality domain that contributes to
      its current processor set and there are threads or processes with
      binding to the locality domain, their binding is changed to another
      locality domain in the processor set. See mpctl(2) for binding to
      processors and locality domains.

      If spu is the last processor in its current processor set, the
      behavior of pset_assign() is dependent on the value of the
      PSET_ATTR_LASTSPU attribute. The following attribute values are
      defined for this attribute:



 Hewlett-Packard Company            - 1 -   HP-UX 11i Version 2: August 2003






 pset_assign(2)                                               pset_assign(2)




      PSET_ATTRVAL_DFLTPSET    [Toc]    [Back]
                Assign the processor to the specified processor set, and
                migrate all threads and processes to the system default
                processor set, PS_DEFAULT.  This is the default behavior.
                If the threads and processes being migrated to the system
                default processor set (pset) have binding to processor or
                locality domain, their binding is reassigned to another
                processor or locality domain in the system default processor
                set.

      PSET_ATTRVAL_FAIL    [Toc]    [Back]
                Make the request fail if there are active threads and
                processes assigned to the processor set.

 EXAMPLE    [Toc]    [Back]
      Reassign spu from its current processor set to new_pset, and retrieve
      the current processor set in old_pset.

      #include  <sys/pset.h>

      spu_t     spu;
      psetid_t  new_pset, old_pset;
      int       ret;

      /*
       * Initialize spu and new_pset first.
       * spu identifies the processor to be reassigned, whereas
       * new_pset identifies the target processor set.
       */
      if ((ret = pset_assign(new_pset, spu, &old_pset)) < 0) {
           perror("pset_assign");
           exit(1);
      }

 RETURN VALUE    [Toc]    [Back]
      pset_assign returns zero on successful completion.  Otherwise, -1 is
      returned and errno is set to indicate the error.

 ERRORS    [Toc]    [Back]
      pset_assign fails if one or more of the following is true:

      [EBUSY]     The processor set currently assigned to the processor spu
                  has active threads and processes, and the processor set
                  attributes do not allow this operation.

      [EFAULT]    The memory location pointed to by opset is not writable by
                  the user.

      [EINTR]     The operation was interrupted.





 Hewlett-Packard Company            - 2 -   HP-UX 11i Version 2: August 2003






 pset_assign(2)                                               pset_assign(2)




      [EINVAL]    The processor spu or processor set pset is not valid.

      [EINVAL]    The spu is not enabled.

      [EINVAL]    The memory location pointed to by opset is NULL, and the
                  PS_QUERY operation is requested.

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

      [EPERM]     The user does not have necessary permissions to assign spu
                  to pset.

 SEE ALSO    [Toc]    [Back]
      mpctl(2), pset_bind(2), pset_create(2), pset_ctl(2), pset_destroy(2),
      pset_getattr(2), pset_setattr(2), privgrp(4).


 Hewlett-Packard Company            - 3 -   HP-UX 11i Version 2: August 2003