NAME
psrset — create and manage processor sets
SYNOPSIS
psrset
[-f]
-a
pset_id
processor_list
psrset
[-f]
-b
pset_id
pid_list
psrset
[-f]
-c
[processor_list]
psrset
[-f]
-d
pset_list
psrset
[-f]
-d
all
psrset
[-f]
-e
pset_id
command
[argument_list]
psrset
[-f]
-g
pset_id
pgid
psrset
[-i]
[pset_list]
psrset
[-f]
-n
pset_id
psrset -p
[processor_list]
psrset -q
[pid_list]
psrset
[-f]
-r
processor_list
psrset
[-f]
-t
pset_id
attribute_name=attribute_value
psrset
[-f]
-u
pid_list
psrset
[-f]
-F
pset_id
psrset
[-f]
-U
pset_id
uid
Real Time Extensions Commands
psrset
[-f]
-l
psrset
[-f]
-m
pset_id
psrset
[-f]
-s
pset_id
psrset
[-f]
-R
[processor_list]
DESCRIPTION
The
psrset
utility controls the management of processor sets.
Processor sets allow a subset of processors in the system to be isolated
for exclusive use by specified threads and processes. Processes may now
be bound to groups of processors rather than just one. Each processor set
represents a separate scheduling allocation domain. Schedulers in each
processor set work independently; there is no load balancing performed
across processor set boundary by the system.
The default processor set (0) always exists and may not be destroyed.
All processes and processors at system init time start out in the
system default processor set. For this reason processor 0 may never
be removed from the default group. (Hence this feature is of no value
on a single processor system.)
A processor belongs to exactly one processor set at a time, and it can
be reassigned from one processor set to another processor set dynamically
with appropriate privileges. There can exist processor sets with no
processors. This may be temporary due to resource needs elsewhere in
the system. (See
pset_assign(2)
for details).
A process or a thread is bound to exactly one processor at a time, and
their binding can be changed from one processor set to another with
appropriate privileges. All threads of a process need not belong to the
same processor set. (See
pset_bind(2)
for details).
A processor set has access permissions, and only the users with
appropriate permissions may perform operations on processor sets.
A superuser or a
PRIV_PSET
privilege user may perform any operation
on processor sets. (See
pset_create(2)
and
pset_setattr(2)
for details).
Options
If no options are specified for the
psrset
command, then the
-i
option is assumed (see below).
The following options are supported:
- -a pset_id processor_list
Assigns
processor_list
to
pset_id.
processor_list
is the list of processors, and
pset_id
is the processor set identification number.
The processors are taken out of their current processor set
and are reassigned to the specified processor set. Processor 0
may not be reassigned.
If the processor being reassigned is the last processor in its
current processor set, the behavior is defined by the
LASTSPU
attribute.
See the
-t
option to define
LASTSPU.
The possible attribute values for
LASTSPU
are as follows:
- DFLTPSET
Default behavior. Reassign the processor to
the specified processor set, and return the
active processes/threads in the processor set
to the default set.
- FAIL
Fail the request.
- -b pset_id pid_list
Binds
pid_list
to
pset_id.
pid_list
is the specified list of processes (including all their threads), and
pset_id
is the specified processor set.
Bindings are inherited, so newly
created threads and processes will inherit their processor set
binding from their parents.
If the target processor
(pset_id)
has no processors assigned, the
behavior is defined by the
EMPTY
attribute.
See the
-t
option to define
EMPTY.
The possible attribute values for
EMPTY
are as follows:
- FAIL
Default behavior. Fail the request.
- -c [processor_list]
Creates a new processor set and displays the
processor set identification number
(pset_id)
for the new processor set.
If a list of processors
(processor_list)
are specified on the command line,
they are assigned to the newly created processor set.
- -d pset_list
- -d all
Destroys the specified list of processor sets
(pset_list).
When the
all
option is specified, all the processor sets in the system are destroyed.
When the processor set has
processors assigned, or there are active processes/threads bound
to the processor set, the behavior is defined by the value of
the
NONEMPTY
attribute.
See the
-t
option to define
NONEMPTY.
The possible attribute values for
NONEMPTY
are as follows:
- DFLTPSET
Default behavior. Return all processors and
threads/processes in the processor set to the default set.
- FAIL
Fail the request if processor set has any
processor assigned, or has active processes or threads.
- FAILBUSY
Fail the request if there are active processes
or threads bound to the processor set.
- -e pset_id command [ argument_list ]
Executes the specified
command
in the specified processor set
(pset_id).
The effect is the same as binding your shell to the target
processor set, executing the command, and changing back to your
original processor set.
The command may have arguments listed in
argument_list.
- -f
Forces the operation if the HP Process Resource Manager (HP PRM)
is installed and configured. The processor sets can also be
configured by PRM.
HP Process Resource Manager is documented in the
HP Process Resource Manager User's Guide.
This option is applicable to all the configuration options to
override the PRM. If the force flag is not used with configuration
options in the presence of PRM, then
psrset
exits with an error message.
IMPORTANT:
If used, the
-f
option must be specified before any other arguments are specified to
the
psrset
command.
- -g pset_id pgid
Binds all the processes (including all their threads) belonging to
the process group
(pgid)
to the specified processor set
(pset_id).
This option is like explicitly listing
all these processes with the
-b
option.
- -i [pset_list]
Displays the processor assignments and attribute values for all
processor sets specified in the list
(pset_list)
or for all sets by default. It will also list the Locality Domains that
belong to the processor sets.
If
pset_list
is not specified, then information for all processor sets are displayed.
If no options are specified for the
psrset
command, then the
-i
option is assumed.
- -n pset_id
Enables external I/O interrupts for all processors assigned to
the specified processor set
(pset_id).
- -p [processor_list]
Displays the processor set assignment for all processors specified
in the list
(processor_list)
or for all processors by default.
- -q [pid_list]
Displays the processor set binding for all processes specified
in the list
(pid_list)
or for all processes by default.
- -r processor_list
Removes
the specified list of processors
(processor_list)
from their current processor
set, and reassigns them back to the default set. This option is
identical to
-a 0 processor_list.
- -t pset_id attribute_name=attribute_value
Changes the attribute value of the specified attribute on the
specified processor set
(pset_id).
Some values may not be be supported.
The following attributes are supported:
- OWNID
Change owner of the specified processor set.
- GRPID
Change group id of the specified processor set.
- PERM
Change access permissions of the specified processor set.
- NONEMPTY
Define behavior on processor destroy request. See the
-d
option.
- EMPTY
Define behavior on request to bind a process or thread to
an empty processor set. See the
-b
option.
- LASTSPU
Define behavior on request to remove the last processor
from a processor set. See
-a
option.
- LCPU
Define the logical processor (LCPU) attribute in the target processor set.
On a multi-threaded processor core, each hardware thread is represented as an LCPU.
If LCPU is disabled, the processor cores in the target processor set
behave as a single threaded core.
However, when LCPU is enabled, the processor cores in the target pset
have hardware multi-threading enabled.
- -u pid_list
Unbinds
pid_list,
the specified list of processes (including all their threads),
from their current processor set returning them to the default
set.
The
-u
option is identical to
-b 0 pid_list.
- -F pset_id
Disables external I/O interrupts for all processors assigned to
the specified processor set
(pset_id).
- -U pset_id uid
Binds all the processes (including all their threads) owned by the
user id
(uid)
to the specified processor set
(pset_id).
This option is like
explicitly listing all these processes with
-b
option.
Real Time Extensions Options
The following options are related to Real Time Extensions
(RTE) for processor sets:
- -l
Lists all the processor sets that are configured as RTE processor set.
- -m pset_id
Marks a processor set with the identification number,
pset_id,
as an RTE processor set. The processors that are part of the
pset_id
processor set become
RTSPU's.
The default processor set which
contains processor 0 may not be configured 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 time of request, these
processors are made unavailable to the kernel daemons. External I/O
interrupts and pending callouts on processors in pset are reassigned to
processors in non-RTE processor sets in the system. The processor set
attribute values are changed to default values for an RTE processor set.
The various failure conditions could be:
The configuring application does not have root privileges.
- -s pset_id
Un-marks the processor set with the identification number,
pset_id,
as an RTE processor set. The processor set is not destroyed.
- -R [processor_list]
Creates a new RTE processor set and displays the
processor set identification number
(pset_id)
for the new processor set.
If a list of processors
(processor_list)
are specified on the command line,
they are assigned to the newly created processor set.
EXTERNAL INFLUENCES
Environment Variables
LANG
provides a default value for the internationalization variables
that are unset or null. If
LANG
is unset or null, the default value of
C
is used (see
lang(5)).
If any of the internationalization variables contains
an invalid setting,
psrset
will behave as if all internationalization variables are set to
C.
See
environ(5).
LC_ALL
determines the locale that overrides any values for locale
categories specified by the settings of
LANG
or any environment variables beginning with
LC_.
LC_MESSAGES
determines the locale that affects the format and
contents of diagnostic messages written to standard error and
the informative messages written to standard output.
International Code Set Support
Single-byte and multi-byte character code sets are supported.
EXAMPLES
psrset Example
Read and display the system processor set configurations
for all processor sets.
If no options are specified for the
psrset
command,
then the
-i
option is assumed.
psrset -a Example
Reassign processors 4 and 1 from their current processor sets to processor
set 5:
psrset -b Example
Change the binding of a running process (pid=1000) to processor set 6:
psrset -c Example
Create a new processor set and assign processors 1, 2 and 4 to the new set:
psrset -e Example
Execute the command
cat foo
in processor set 4:
psrset -t Examples
Change behavior for processor set destroy operation to fail the
request if there are active processes bound to the processor set:
psrset -t NONEMPTY=FAILBUSY
Change the ownership of processor set 3 to user id 100:
For processor set 2, change access permissions to 666:
RETURN VALUE
psrset
returns zero on successful completion. Otherwise, a non-zero
value is returned and the message is displayed to indicate the error.
AUTHOR
psrset
was developed by HP.
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