SIMPLE SOLUTIONS

SCHED_GET_PRIORITY_MAX(2) - man page online | system calls

Get static priority range.

Chapter
2015-08-08
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. Sup‐ ported 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/mini‐ mum 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 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 http://www.kernel.org/doc/man-pages/.
Linux 2015-08-08 SCHED_GET_PRIORITY_MAX(2)
This manual Reference Other manuals
sched_get_priority_max(2) referred by pthread_attr_setschedparam(3) | pthread_setschedparam(3) | pthread_setschedprio(3) | sched(7) | sched_get_priority_max(2freebsd) | sched_get_priority_min(2freebsd) | sched_getparam(2freebsd) | sched_getscheduler(2freebsd) | sched_rr_get_interval(2freebsd) | sched_setaffinity(2) | sched_setattr(2) | sched_setparam(2) | sched_setparam(2freebsd) | sched_setscheduler(2) | sched_setscheduler(2freebsd) | syscalls(2)
refer to sched(7) | sched_setaffinity(2) | sched_setparam(2) | sched_setscheduler(2)