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SCHED_GET_PRIORITY_MAX(2) | System Calls Manual | SCHED_GET_PRIORITY_MAX(2) |
NAME¶
sched_get_priority_max
,
sched_get_priority_min
,
sched_rr_get_interval
—
get scheduling parameter limits
LIBRARY¶
Standard C Library (libc, -lc)SYNOPSIS¶
#include <sched.h>
int
sched_get_priority_max
(int
policy);
int
sched_get_priority_min
(int
policy);
int
sched_rr_get_interval
(pid_t
pid, struct timespec
*interval);
DESCRIPTION¶
Thesched_get_priority_max
() and
sched_get_priority_min
() system calls return the
appropriate maximum or minimum, respectively, for the scheduling policy
specified by policy. The
sched_rr_get_interval
() system call updates the
timespec structure referenced by the
interval argument to contain the current execution time
limit (i.e., time quantum) for the process specified by
pid. If pid is zero, the current
execution time limit for the calling process is returned.
The value of policy should be one of the scheduling policy values defined in <sched.h>:
- [
SCHED_FIFO
] - First-in-first-out fixed priority scheduling with no round robin scheduling;
- [
SCHED_OTHER
] - The standard time sharing scheduler;
- [
SCHED_RR
] - Round-robin scheduling across same priority processes.
RETURN VALUES¶
If successful, thesched_get_priority_max
() and
sched_get_priority_min
() system calls shall return the
appropriate maximum or minimum values, respectively. If unsuccessful, they
shall return a value of -1 and set errno to indicate the
error.
The sched_rr_get_interval
() function returns the
value 0 if successful; otherwise the value -1 is returned and
the global variable errno is set to indicate the
error.
ERRORS¶
On failure errno will be set to the corresponding value:- [
EINVAL
] - The value of the policy argument does not represent a defined scheduling policy.
- [
ENOSYS
] - The
sched_get_priority_max
(),sched_get_priority_min
(), andsched_rr_get_interval
() system calls are not supported by the implementation. - [
ESRCH
] - No process can be found corresponding to that specified by pid.
SEE ALSO¶
sched_getparam(2), sched_getscheduler(2), sched_setparam(2), sched_setscheduler(2)STANDARDS¶
Thesched_get_priority_max
(),
sched_get_priority_min
(), and
sched_rr_get_interval
() system calls conform to
IEEE Std 1003.1b-1993 (“POSIX.1b”).
March 12, 1998 | Linux 4.9.0-9-amd64 |