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sched_getscheduler(3)
NAME
  sched_getscheduler - Return the scheduling policy of a process (P1003.1b)

SYNOPSIS
  #include <sched.h>

  int sched_getscheduler (
  pid_t pid);

PARAMETERS
  pid	  The ID of the process for which the scheduling policy is obtained.
	  If pid is zero, the scheduling policy of the calling process is
	  obtained.

DESCRIPTION
  The sched_getscheduler function returns the current scheduling policy of a
  process. The values that can be returned are defined in the header file
  <sched.h>.

  The sched_setscheduler function changes the scheduling policy and priority
  of a process.	 Changing the scheduling policy and priority ensures that an
  application can determine more effectively when a process will run.

  The realtime scheduling policies are as follows:

  ·  SCHED_FIFO - specifies the first-in, first-out (FIFO) scheduling policy

  ·  SCHED_RR - specifies the round-robin scheduling policy

  ·  SCHED_OTHER - specifies the standard timesharing scheduling policy

  The SCHED_FIFO and SCHED_RR scheduling policies are fixed-priority
  scheduling policies. You can specify a priority for your process and the
  scheduler will not adjust it.	 Setting priorities, in conjunction with a
  SCHED_FIFO scheduling policy, allows a critical process to run as soon as
  it is ready, for as long as it needs to run, because the process will
  preempt other lower priority processes.

  The round-robin scheduling policy is similar to first in-first out, but
  also imposes a quantum on execution time. Use the sched_rr_get_interval
  function to determine the current quantum for process execution under the
  SCHED_RR scheduling policy.

  The scheduler adjusts process priorities running under the timesharing
  scheduling policy.

  No special privileges are needed to use the sched_getscheduler function.


RETURN VALUES
  On a successful call to sched_getscheduler the scheduling policy of the
  process is returned. If there is an error, -1 is returned and errno is set
  to indicate the error.

ERRORS
  The sched_getscheduler function fails under the following condition:

  [ESRCH]	 No process can be found corresponding to that specified by
		 pid.

RELATED INFORMATION
  Functions: getpid(2), sched_getparam(3), sched_setparam(3),
  sched_setscheduler(3)

Index for Section 3

Alphabetical listing for S

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