.\" Copyright (C) Tom Bjorkholm & Markus Kuhn, 1996 .\" .\" SPDX-License-Identifier: GPL-2.0-or-later .\" .\" 1996-04-01 Tom Bjorkholm .\" First version written .\" 1996-04-10 Markus Kuhn .\" revision .\" .TH sched_get_priority_max 2 2024-05-02 "Linux man-pages 6.9.1" .SH NAME sched_get_priority_max, sched_get_priority_min \- get static priority range .SH LIBRARY Standard C library .RI ( libc ", " \-lc ) .SH SYNOPSIS .nf .B #include .P .BI "int sched_get_priority_max(int " policy ); .BI "int sched_get_priority_min(int " policy ); .fi .SH DESCRIPTION .BR sched_get_priority_max () returns the maximum priority value that can be used with the scheduling algorithm identified by .IR policy . .BR sched_get_priority_min () returns the minimum priority value that can be used with the scheduling algorithm identified by .IR policy . Supported .I policy values are .BR SCHED_FIFO , .BR SCHED_RR , .BR SCHED_OTHER , .BR SCHED_BATCH , .BR SCHED_IDLE , and .BR SCHED_DEADLINE . Further details about these policies can be found in .BR sched (7). .P Processes with numerically higher priority values are scheduled before processes with numerically lower priority values. Thus, the value returned by .BR sched_get_priority_max () will be greater than the value returned by .BR sched_get_priority_min (). .P Linux allows the static priority range 1 to 99 for the .B SCHED_FIFO and .B SCHED_RR policies, and the priority 0 for the remaining policies. Scheduling priority ranges for the various policies are not alterable. .P 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 .BR sched_get_priority_max () and .BR sched_get_priority_min () POSIX.1 requires .\" POSIX.1-2001, POSIX.1-2008 (XBD 2.8.4) a spread of at least 32 between the maximum and the minimum values for .B SCHED_FIFO and .BR SCHED_RR . .P POSIX systems on which .BR sched_get_priority_max () and .BR sched_get_priority_min () are available define .B _POSIX_PRIORITY_SCHEDULING in .IR . .SH RETURN VALUE On success, .BR sched_get_priority_max () and .BR sched_get_priority_min () return the maximum/minimum priority value for the named scheduling policy. On error, \-1 is returned, and .I errno is set to indicate the error. .SH ERRORS .TP .B EINVAL The argument .I policy does not identify a defined scheduling policy. .SH STANDARDS POSIX.1-2008. .SH HISTORY POSIX.1-2001. .SH SEE ALSO .ad l .nh .BR sched_getaffinity (2), .BR sched_getparam (2), .BR sched_getscheduler (2), .BR sched_setaffinity (2), .BR sched_setparam (2), .BR sched_setscheduler (2), .BR sched (7)