__pset_rtctl.2 (2010 09)

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__pset_rtctl(2) __pset_rtctl(2)

NAME

__pset_rtctl() - real-time processor set control

SYNOPSIS

#include <sys/rtpset.h>

int __pset_rtctl(

pset_rt_req_t request ,

psetid_t pset ,

int arg,

);

DESCRIPTION

HP-UX Processor Sets allow a subset of processors in the system to be isolated for exclusive use by

speciﬁed threads and processes. Only the threads bound to a processor set can execute on processors in

that processor set (see pset_create (2)).

The

__pset_rtctl()

function extends processor set functionality for real-time applications to minim-

ize operating system activities in a processor set. A processor set can be conﬁgured as a real-time proces-

sor set (referred to as RTE processor set). An RTE processor set has the following special features that

are not available in standard processor sets:

No Kernel Daemons

The scheduler does not schedule kernel daemons on processors in the RTE processor set. Kernel

daemons are restricted to processors in non-RTE processor sets.

No External I/O Interrupts

External I/O interrupts on processors in the RTE processor set are disabled. The system is

reconﬁgured to not deliver any external I/O interrupts to processors in the RTE processor set. (The

clock interrupt still continues to come on each processor though). This feature may not be supported

on all platforms (see intctl (1M) for details).

Callouts Migration

All pending callouts on processors in the RTE processor set are reassigned to processors in non-RTE

processor sets. However, if a real-time application in an RTE processor set requests a service which

requires callout support in the kernel, such callouts may execute on RTE processors.

The system always has at least one non-RTE processor set. The system default processor set (see

pset_create (2)) cannot be conﬁgured as an RTE processor set. Since the system default processor set is

never empty, there is always at least one processor in a non-RTE processor set to execute the kernel dae-

mons, I/O interrupts and callouts for the system.

The request argument speciﬁes the operation to perform on the processor set pset for real time extension.

The following values are supported:

RTE_PSET_CONFIG Conﬁgure the speciﬁed processor set, pset, as an RTE processor set.

The processor set may or may not have processors assigned at this

point. If pset has processors assigned to it at the time of this request,

these processors are made unavailable to the kernel daemons. Exter-

nal I/O interrupts and pending callouts on processors in pset are reas-

signed to processors in non-RTE processor sets in the system. The pro-

cessor set attribute values are changed to default values for an RTE

processor set. If pset has any assigned workload, it continues to exe-

cute in that processor set. The arg argument is ignored.

RTE_PSET_UNCONFIG Unconﬁgure the speciﬁed processor set pset as an RTE processor set.

The processors, if any, in this processor set are made available to the

kernel daemons. The system may redistribute the external I/O inter-

rupts with availability of these processors. Pending callouts in the sys-

tem are not redistributed to these processors. The processor set attri-

bute values are restored to default values for a non-RTE processor set

as applicable. If pset has any assigned workload, it continues to exe-

cute in that processor set. The arg argument is ignored.

RTE_PSET_GETFIRSTPSET Return the ID of the ﬁrst RTE processor set in the system. The pset

and arg arguments are ignored.

HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1

Summary of content (4 pages)

PAGE 1
__pset_rtctl(2) __pset_rtctl(2) NAME __pset_rtctl() - real-time processor set control SYNOPSIS #include int __pset_rtctl( pset_rt_req_t request , psetid_t pset , int arg , ); A DESCRIPTION HP-UX Processor Sets allow a subset of processors in the system to be isolated for exclusive use by specified threads and processes. Only the threads bound to a processor set can execute on processors in that processor set (see pset_create (2)).
PAGE 2
__pset_rtctl(2) RTE_PSET_GETNEXTPSET __pset_rtctl(2) Return the ID of the next RTE processor set in the system after pset . The arg argument is ignored. Typically, RTE_PSET_GETFIRSTPSET is called to determine the first RTE processor set. RTE_PSET_GETNEXTPSET is then called in a loop (until the call returns -1) to determine the IDs of the remaining RTE processor sets in the system. A See pset_ctl (2) for additional processor set query operations.
PAGE 3
__pset_rtctl(2) __pset_rtctl(2) allow removal of the last processor from an RTE processor set even if the processor set is busy. See pset_setattr (2) for supported values. PSET_ATTR_NONEMPTY Indicates the behavior on a request to destroy a non-empty processor set. A non-empty processor set has at least one processor assigned to it. For RTE processor sets, such a request will be rejected by default.
PAGE 4
__pset_rtctl(2) __pset_rtctl(2) } if ((ret = __pset_rtctl(RTE_PSET_CONFIG, new_psetid, 0)) < 0) { perror("__pset_rtctl()"); exit(2); } A _A SEE ALSO psrset(1M), pset_assign(2), pset_bind(2), pset_ctl(2), pset_destroy(2), pset_getattr(2), pset_setattr(2), sysconf(2), privileges(5).