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__ppc_set_ppr_med.3: Document PPC functions providing access to PPR 

GNU C Library commit 1747fcda4902a3b46183d93fb16ed9b436b2608b
extends the priorities that can be set to the Program Priority
Register (PPR), with the functions: __ppc_set_ppr_very_low(3)
and __ppc_set_ppr_med_high(3).

Signed-off-by: Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
Gabriel F. T. Gomes 2015-10-08 21:16:38 +01:00 committed by Michael Kerrisk
parent d27bed925b
commit eb6b6909a7
1 changed files with 37 additions and 4 deletions
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man3/__ppc_set_ppr_med.3
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@ -25,16 +25,20 @@
.TH __PPC_SET_PPR_MED 3 2015-08-05 "GNU C Library" "Linux\
Programmer's Manual"
.SH NAME
__ppc_set_ppr_med, __ppc_set_ppr_low, __ppc_set_ppr_med_low \-
__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
.SH SYNOPSIS
.B #include <sys/platform/ppc.h>
.sp
.B void __ppc_set_ppr_med(void);
.br
.B void __ppc_set_ppr_very_low(void);
.br
.B void __ppc_set_ppr_low(void);
.br
.B void __ppc_set_ppr_med_low(void);
.br
.B void __ppc_set_ppr_med_high(void);
.SH DESCRIPTION
These functions provide access to the
.I Program Priority Register
@ -44,13 +48,17 @@ 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 three unprivileged states available are covered by the following functions:
The four unprivileged states available are covered by the following functions:
.IP * 3
.BR __ppc_set_ppr_med ()
sets the Program Priority Register value to
.IR medium
(default).
.IP *
.BR __ppc_set_ppr_very_low ()
sets the Program Priority Register value to
.IR "very low" .
.IP *
.BR __ppc_set_ppr_low ()
sets the Program Priority Register value to
.IR low .
@ -58,8 +66,31 @@ sets the Program Priority Register value to
.BR __ppc_set_ppr_med_low ()
sets the Program Priority Register value to
.IR "medium low" .
.P
The privileged state
.IR "medium high"
may also be set during certain time intervals by problem-state (unprivileged)
programs, with the following function:
.IP * 3
.BR __ppc_set_ppr_med_high ()
sets the Program Priority to
.IR "medium high" .
.P
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.
.SH VERSIONS
These functions first appeared in glibc in version 2.18.
The functions
.BR __ppc_set_ppr_med (),
.BR __ppc_set_ppr_low ()
and
.BR __ppc_set_ppr_med_low ()
are provided by glibc since version 2.18.
The functions
.BR __ppc_set_ppr_very_low ()
and
.BR __ppc_set_ppr_med_high ()
first appeared in glibc in version 2.23.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
@ -71,8 +102,10 @@ l l l.
Interface Attribute Value
T{
.BR __ppc_set_ppr_med (),
.BR __ppc_set_ppr_very_low (),
.BR __ppc_set_ppr_low (),
.BR __ppc_set_ppr_med_low ()
.BR __ppc_set_ppr_med_low (),
.BR __ppc_set_ppr_med_high ()
T} Thread safety MT-Safe
.TE
.ad