sched_get_priority_max

SCHED_GET_PRIORITY_MAX(2)   Linux Programmer's Manual  SCHED_GET_PRIORITY_MAX(2)



NAME
       sched_get_priority_max, sched_get_priority_min  - get static priority
       range

SYNOPSIS
       #include <sched.h>

       int sched_get_priority_max(int policy);

       int sched_get_priority_min(int policy);

DESCRIPTION
       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, SCHED_BATCH,
       SCHED_IDLE, and SCHED_DEADLINE.  Further details about these policies can
       be found in sched(7).

       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 range 1 to 99 for the SCHED_FIFO and
       SCHED_RR policies, and the priority 0 for the remaining policies.
       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 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>.

RETURN VALUE
       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.

ERRORS
       EINVAL The argument policy does not identify a defined scheduling policy.

CONFORMING TO
       POSIX.1-2001, POSIX.1-2008.

SEE ALSO
       sched_getaffinity(2), sched_getparam(2), sched_getscheduler(2),
       sched_setaffinity(2), sched_setparam(2), sched_setscheduler(2), sched(7)

COLOPHON
       This page is part of release 5.09 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
       https://www.kernel.org/doc/man-pages/.



Linux                              2017-09-15          SCHED_GET_PRIORITY_MAX(2)