rtsched.1 (2010 09)

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rtsched(1) rtsched(1)

NAME

rtsched - execute process/lightweight process (LWP) with real-time priority

SYNOPSIS

rtsched -s scheduler -p priority command [arguments ]

rtsched [-s scheduler ] -p priority -P

pid

rtsched [-s scheduler ] -p priority

-G lwpid

rtsched [-s scheduler ] -p priority -P

pid -G ALL

DESCRIPTION

rtsched executes command with POSIX or HP-UX real-time priority, or changes the real-time priority

of currently executing process (pid) or lightweight process (lwpid ).

All POSIX real-time priority processes or LWPs are of greater scheduling importance than

processes/LWPs with HP-UX real-time or HP-UX timeshare priority. All HP-UX real-time priority

processes/LWPs are of greater scheduling importance than HP-UX timeshare priority processes/LWPs,

but are of lesser importance than POSIX real-time processes/LWPs.

Neither POSIX nor HP-UX real-time processes/LWPs are subject to degradation.

POSIX real-time processes/LWPs may be scheduled with one of three different POSIX real-time

schedulers: SCHED_FIFO, SCHED_RR, or SCHED_RR2. See rtsched (2) for details.

rtsched is a superset of rtprio. See rtprio (1).

Options

-s scheduler Specify the desired scheduler:

POSIX real-time schedulers: SCHED_FIFO

SCHED_RR

SCHED_RR2

HP-UX real-time scheduler: SCHED_RTPRIO

HP-UX timeshare scheduler: SCHED_HPUX

SCHED_NOAGE

-p priority Specify priority range; any integer within the inclusive priority range of the correspond-

ing scheduler. -p priority is required for all schedulers except SCHED_HPUX. If

scheduler is SCHED_HPUX, the priority argument is ignored. The default priority range

of each scheduler is as follows:

scheduler highest priority lowest priority

SCHED_FIFO 31 0

SCHED_RR 31 0

SCHED_RR2 31 0

SCHED_RTPRIO 0 127

SCHED_NOAGE 178 255

SCHED_HPUX N/A N/A

Note : Higher numerical values for the priority represent higher priorities under POSIX

real-time schedulers, whereas lower numerical values for the priority represent higher

priorities under HP-UX real-time and timeshare schedulers.

-P Specify an already executing process ID (pid ).

-G lwpid Specify an already executing lightweight process ID (lwpid ). The target LWP (lwpid ) can

be in any process.

-G ALL Select all the LWPs in an already executing process (speciﬁed with -P pid). When

scheduling policy is not speciﬁed explicitly using the -s option, the process’s current

scheduling policy will be used. If the requested priority value is in the range for this

scheduling policy, the scheduling policy and priority of the process and all its LWPs will

be changed to these values. Please note that it may cause the scheduling policy to be

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

Summary of content (2 pages)

PAGE 1
rtsched(1) rtsched(1) NAME rtsched - execute process/lightweight process (LWP) with real-time priority SYNOPSIS rtsched -s scheduler -p priority command [arguments ] rtsched [-s scheduler ] -p priority -P pid rtsched [-s scheduler ] -p priority -G lwpid rtsched [-s scheduler ] -p priority -P pid -G ALL DESCRIPTION rtsched executes command with POSIX or HP-UX real-time priority, or changes the real-time priority of currently executing process (pid ) or lightweight process (lwpid ).
PAGE 2
rtsched(1) rtsched(1) changed for some LWPs. If the user is not a member of a group having PRIV_RTSCHED access and is not the user with appropriate privileges, command is not scheduled, or pid ’s/ lwpid ’s real-time priority is not changed. When changing the real-time priority of a currently executing process/LWP, the effective user ID of the calling process must be the user with appropriate privileges, or the real or effective user ID must match the real or saved user ID of the process to be modified.