__ppc_set_ppr_low (3)

Leading comments

Copyright (c) 2015, 2016 IBM Corporation.

%%%LICENSE_START(VERBATIM)
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided that
the entire resulting derived work is distributed under the terms of
a permission notice identical to this one.

Since the Linux k...

(The comments found at the beginning of the groff file "man3/__ppc_set_ppr_low.3".)

NAME

__ppc_set_ppr_med, __ppc_set_ppr_very_low, __ppc_set_ppr_low, __ppc_set_ppr_med_low, __ppc_set_ppr_med_high - Set the Program Priority Register

SYNOPSIS

#include <sys/platform/ppc.h>

void __ppc_set_ppr_med(void);
void __ppc_set_ppr_very_low(void);
void __ppc_set_ppr_low(void);
void __ppc_set_ppr_med_low(void);
void __ppc_set_ppr_med_high(void);

DESCRIPTION

These functions provide access to the Program Priority Register (PPR) on the Power architecture. The PPR is a 64-bit register that controls the program's priority. By adjusting the PPR value the programmer may improve system throughput by causing system resources to be used more efficiently, especially in contention situations. The available unprivileged states are covered by the following functions:

*

__ppc_set_ppr_med() sets the Program Priority Register value to medium (default).

*

__ppc_set_ppr_very_low() sets the Program Priority Register value to very low.

*

__ppc_set_ppr_low() sets the Program Priority Register value to low.

*

__ppc_set_ppr_med_low() sets the Program Priority Register value to medium low. The privileged state medium high may also be set during certain time intervals by problem-state (unprivileged) programs, with the following function:

*

__ppc_set_ppr_med_high() sets the Program Priority to medium high. If the program priority is medium high when the time interval expires or if an attempt is made to set the priority to medium high when it is not allowed, the priority is set to medium.

VERSIONS

The functions __ppc_set_ppr_med(), __ppc_set_ppr_low() and __ppc_set_ppr_med_low() are provided by glibc since version 2.18. The functions __ppc_set_ppr_very_low() and __ppc_set_ppr_med_high() first appeared in glibc in version 2.23.

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
__ppc_set_ppr_med(), __ppc_set_ppr_very_low(), __ppc_set_ppr_low(), __ppc_set_ppr_med_low(), __ppc_set_ppr_med_high()	Thread safety	MT-Safe

CONFORMING TO

These functions are nonstandard GNU extensions.

SEE ALSO

__ppc_yield(3)
Power ISA, Book II - Section 3.1 (Program Priority Registers)

COLOPHON

This page is part of release 4.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at www.kernel.org/doc/man-pages