HP-UX Reference (11i v2 07/12) - 2 System Calls (vol 5)

p
pset_assign(2) pset_assign(2)
NAME
pset_assign() - change processor set assignment
SYNOPSIS
#include <sys/pset.h>
int pset_assign(
psetid_t
pset,
spu_t
spu,
psetid_t *
opset
);
DESCRIPTION
The pset_assign()
function assigns the processor spu to the processor set pset, removing the processor
spu from its current processor set. A processor can 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 user with the PSET privilege or a user with WRITE permissions on the processor sets can change the
processor set assignment for a processor using the pset_assign()
function. A user without the PSET
privilege 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 user with the
PSET privilege
can 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 proces-
sor spu is returned in opset. Neither WRITE permission nor the PSET privilege 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 pro-
cessor 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:
PSET_ATTRVAL_DFLTPSET
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
Make the request fail if there are active threads and processes assigned to the processor set.
Security Restrictions
Some or all of the actions associated with this system call require the PSET privilege. Processes owned by
the superuser have this privilege. Processes owned by other users can have this privilege, depending on
system configuration. See privileges(5) for more information about privileged access on systems that sup-
port fine-grained privileges.
EXAMPLE
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;
260 Hewlett-Packard Company − 1 − HP-UX 11i Version 2: December 2007 Update