processor_exbind(2)                              processor_exbind(2)


       NAME
             processor_exbind - exclusively bind or unbind a processor

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

       DESCRIPTION
             processor_exbind binds an LWP or set of LWPs to a specific
             processor.  processorid is the ID of a processor.  This is an
             exclusive binding; the processor is precluded from running
             LWPs that are not exclusively bound.  idtype and idlist are
             used to identify a set of LWPs.  If obind is not NULL, it
             points to a variable in which the previous binding is
             returned.  idtype must be set to P_PID and idlist is a process
             ID list specifying the LWPs to be bound.  The valid values for
             idtype and corresponding interpretations of idlist are as
             follows:

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

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

             When the LWP identified by idlist has been bound, it will
             execute only on the processor specified by processorid (even
             if other processors are available), except briefly, if the LWP
             requires a resource that only another processor can provide.
             Once one or more LWPs are exclusively bound to a processor
             with a single call to processor_exbind, all subsequent
             requests fail with EBUSY, unless the current exclusive binding
             to the processor is undone or those LWPs exit.  The processor
             so bound will not schedule any LWP that is not exclusively
             bound.  The system imposes a limit on the number of processors
             that can be exclusively bound.

             The processor_exbind 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


                           Copyright 1994 Novell, Inc.               Page 1

      processor_exbind(2)                              processor_exbind(2)


            function and the completion of the operation will, typically,
            be of very short duration.

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

            If the LWP(s) specified by idlist is already bound to a
            different processor, the binding for that LWP will be changed
            to the processor specified by processorid.  If obind is not
            NULL and the LWP 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_exbind 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 idlist 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_exbind returns a negative value and sets
            errno to identify the error.

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

           EPERM  The calling process does not have appropriate privilege
                   for one or more of the specified LWPs.

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





                          Copyright 1994 Novell, Inc.               Page 2

       processor_exbind(2)                              processor_exbind(2)


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

            EBUSY  A process specified by idlist is bound exclusively to
                    another processor or there are already LWPs exclusively
                    bound to the processor specified by processorid.

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

            EIO    The specified processor is not operational.

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


































                           Copyright 1994 Novell, Inc.               Page 3