| NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO | COLOPHON | The Linux Programming Interface |
SCHED_GET_PRIORITY_MAX(2) Linux Programmer's Manual SCHED_GET_PRIORITY_MAX(2)
sched_get_priority_max, sched_get_priority_min - get static priority range
#include <sched.h>
int sched_get_priority_max(int policy);
int sched_get_priority_min(int policy);
sched_get_priority_max() returns the maximum priority value that can be used
with the scheduling algorithm identified by policy. sched_get_priority_min()
returns the minimum priority value that can be used with the scheduling
algorithm identified by policy. Supported policy values are SCHED_FIFO,
SCHED_RR, SCHED_OTHER, and SCHED_BATCH. Further details about these policies
can be found in sched_setscheduler(2).
Processes with numerically higher priority values are scheduled before
processes with numerically lower priority values. Thus, the value returned by
sched_get_priority_max() will be greater than the value returned by
sched_get_priority_min().
Linux allows the static priority value range 1 to 99 for SCHED_FIFO and
SCHED_RR and the priority 0 for SCHED_OTHER and SCHED_BATCH. Scheduling
priority ranges for the various policies are not alterable.
The range of scheduling priorities may vary on other POSIX systems, thus it is
a good idea for portable applications to use a virtual priority range and map
it to the interval given by sched_get_priority_max() and
sched_get_priority_min(). POSIX.1-2001 requires a spread of at least 32
between the maximum and the minimum values for SCHED_FIFO and SCHED_RR.
POSIX systems on which sched_get_priority_max() and sched_get_priority_min()
are available define _POSIX_PRIORITY_SCHEDULING in <unistd.h>.
On success, sched_get_priority_max() and sched_get_priority_min() return the
maximum/minimum priority value for the named scheduling policy. On error, -1
is returned, and errno is set appropriately.
EINVAL The argument policy does not identify a defined scheduling policy.
POSIX.1-2001.
sched_getaffinity(2), sched_getparam(2), sched_getscheduler(2),
sched_setaffinity(2), sched_setparam(2), sched_setscheduler(2)
Programming for the real world - POSIX.4 by Bill O. Gallmeister, O'Reilly &
Associates, Inc., ISBN 1-56592-074-0
This page is part of release 3.32 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
Linux 2006-03-23 SCHED_GET_PRIORITY_MAX(2)
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