processor_bind(2)                                  processor_bind(2)


       NAME
             processor_bind - bind or unbind to a processor

       SYNOPSIS
             #include <sys/types.h>
             #include <sys/procset.h>
             #include <sys/processor.h>
             int processor_bind(idtype_t idtype, id_t id,
                   processorid_t processorid, processorid_t *obind);

       DESCRIPTION
             processor_bind binds a process, an LWP, or set of LWPs to a
             specific processor.  processorid is the ID of a processor.
             idtype and id are used to identify the processes or LWPs to be
             bound.  If obind is not NULL, it points to a variable in which
             the previous binding is returned.  The valid values for idtype
             and corresponding interpretations of id are as follows:

             P_PID id is a process ID.  The operation shall apply to all
                   LWPs currently associated with the specified process.

            P_LWPID id is an LWP ID specifying a single LWP, within the
                     same process as the caller, to which the operation
                     shall apply.

             When the process identified by id has been bound, it will
             execute only on the processor specified by processorid (even
             if other processors are available), except briefly, if the
             process requires a resource that only another processor can
             provide.  The processor may continue to run other processes.
             in addition to the one specified by id.  The processor_bind
             call will fail if the process specified by id is bound
             exclusively to another processor or if there are already
             processes exclusively bound to the processor specified by
             processorid.

             The processor_bind call is not guaranteed to be synchronous
             with the binding operation.  If the binding operation cannot
             be completed immediately, the call may return before the
             operation completes.  Any delay between the return of the
             function and the completion of the operation will, typically,
             be of very short duration.

             If processorid is PBIND_NONE, the specified process is
             unbound; that is, it is made free to run on any processor.



                           Copyright 1994 Novell, Inc.               Page 1

      processor_bind(2)                                  processor_bind(2)


            If the process specified by id is already bound to a different
            processor, the binding for that process will be changed to the
            processor specified by processorid.  If obind is not NULL and
            the process is currently bound to a processor, that
            processorid is returned by obind.

            The processor binding is inherited by any children created by
            a fork(2) call, or _lwp_create(2), and does not change across
            a call to exec(2).

            To bind or unbind an LWP, the real or effective user ID of the
            caller must match the real or saved [from exec(2)] user ID of
            the process being bound or unbound, or the caller must have
            appropriate privileges.

         Return Values
            On success, processor_bind returns 0.  if obind is not NULL,
            the previous binding of the specified LWP shall be returned in
            the location pointed to by obind.  If obind is not NULL and
            idtype and id specify more than one LWP, the previous binding
            shall be returned for a random LWP within the specified set.
            The previous binding shall be the processor ID of the
            processor to which the LWP was bound, or PBIND_NONE if the LWP
            was previously unbound.

            On failure, processor_bind returns a negative value and sets
            errno to identify the error.

         Errors
            In the following conditions, processor_bind fails and sets
            errno to:

           EPERM  The calling process does not have appropriate privilege.

           EINVAL An invalid idtype or processorid was specified, or the
                   specified processor is currently offline.

           ESRCH  None of the specified LWPs exist or idtype was P_LWPID
                   and id specified an LWP that was not within the
                   caller's process.

           EBUSY  The process specified by id is bound exclusively to
                   another processor or there are already processes or
                   LWPs exclusively bound to the processor specified by
                   processorid.



                          Copyright 1994 Novell, Inc.               Page 2

       processor_bind(2)                                  processor_bind(2)


            EFAULT obind is not NULL and points to an invalid address.

            EIO    The specified processor is not operational.

       REFERENCES
             pbind(1M), pexbind(1M)

       NOTICES
          Considerations for Lightweight Processes
             In addition to binding processes to a processor, the P_LWPID
             idtype (see DESCRIPTION) can be used by a process to bind
             individual LWPs in that process.  There is no way for a
             process to bind LWPs in another process.



































                           Copyright 1994 Novell, Inc.               Page 3