__ppc_set_ppr_med(3) — Linux manual page

__ppc_set_ppr_med(3)    Library Functions Manual    __ppc_set_ppr_med(3)

Programmer's Manual"

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

LIBRARY

       Standard C library (libc, -lc)

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.

ATTRIBUTES

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ __ppc_set_ppr_med(),                │ Thread safety │ MT-Safe │
       │ __ppc_set_ppr_very_low(),           │               │         │
       │ __ppc_set_ppr_low(),                │               │         │
       │ __ppc_set_ppr_med_low(),            │               │         │
       │ __ppc_set_ppr_med_high()            │               │         │
       └─────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       GNU.

HISTORY

       __ppc_set_ppr_med()
       __ppc_set_ppr_low()
       __ppc_set_ppr_med_low()
              glibc 2.18.

       __ppc_set_ppr_very_low()
       __ppc_set_ppr_med_high()
              glibc 2.23.

NOTES

       The functions __ppc_set_ppr_very_low() and
       __ppc_set_ppr_med_high() will be defined by <sys/platform/ppc.h>
       if _ARCH_PWR8 is defined.  Availability of these functions can be
       tested using #ifdef _ARCH_PWR8.

SEE ALSO

       __ppc_yield(3)

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

COLOPHON

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Linux man-pages 6.9.1          2024-05-02           __ppc_set_ppr_med(3)

Pages that refer to this page: __ppc_yield(3)

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