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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 | Debian |