NAME
schedgetprioritymax, schedgetprioritymin - get static priority range SYNOPSIS
#include
int schedgetprioritymax(int policy); int schedgetprioritymin(int policy); DESCRIPTION schedgetprioritymax() returns the maximum priority value that can be used with the scheduling algorithm identified by policy. schedgetprioritymin() returns the minimum priority value that can be used with the scheduling algorithm identified by policy. Supported policy values are SCHEDFIFO, SCHEDRR, SCHEDOTHER, and SCHEDBATCH. Further details about these policies can be found in schedsetsched‐ uler(2). Processes with numerically higher priority values are scheduled before processes with numerically lower priority values. Thus, the value returned by schedgetprioritymax() will be greater than the value returned by schedgetprioritymin(). Linux allows the static priority value range 1 to 99 for SCHEDFIFO and SCHEDRR and the priority 0 for SCHEDOTHER and SCHEDBATCH. Schedul‐ ing 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 pri‐ ority range and map it to the interval given by schedgetprior‐ itymax() and schedgetprioritymin(). POSIX.1-2001 requires a spread of at least 32 between the maximum and the minimum values for SCHEDFIFO and SCHEDRR. POSIX systems on which schedgetprioritymax() and schedgetprior‐ itymin() are available define POSIXPRIORITYSCHEDULING in
. RETURN VALUE On success, schedgetprioritymax() and schedgetprioritymin() return the maximum/minimum priority value for the named scheduling pol‐ icy. On error, -1 is returned, and errno is set appropriately. ERRORS EINVAL The argument policy does not identify a defined scheduling pol‐ icy. CONFORMING TO
POSIX.1-2001. SEE ALSO schedgetaffinity(2), schedgetparam(2), schedgetscheduler(2), schedsetaffinity(2), schedsetparam(2), schedsetscheduler(2)
Programming for the real world - POSIX.4 by Bill O. Gallmeister,
O'Reilly & Associates, Inc., ISBN 1-56592-074-0. COLOPHON
This page is part of release 3.53 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 SCHEDGETPRIORITYMAX(2)