sched_setparam(3p) — Linux manual page


SCHED_SETPARAM(3P)      POSIX Programmer's Manual     SCHED_SETPARAM(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

NAME         top

       sched_setparam — set scheduling parameters (REALTIME)

SYNOPSIS         top

       #include <sched.h>

       int sched_setparam(pid_t pid, const struct sched_param *param);

DESCRIPTION         top

       The sched_setparam() function shall set the scheduling parameters
       of the process specified by pid to the values specified by the
       sched_param structure pointed to by param.  The value of the
       sched_priority member in the sched_param structure shall be any
       integer within the inclusive priority range for the current
       scheduling policy of the process specified by pid.  Higher
       numerical values for the priority represent higher priorities.
       If the value of pid is negative, the behavior of the
       sched_setparam() function is unspecified.

       If a process specified by pid exists, and if the calling process
       has permission, the scheduling parameters shall be set for the
       process whose process ID is equal to pid.

       If pid is zero, the scheduling parameters shall be set for the
       calling process.

       The conditions under which one process has permission to change
       the scheduling parameters of another process are implementation-

       Implementations may require the requesting process to have
       appropriate privileges to set its own scheduling parameters or
       those of another process.

       See Scheduling Policies for a description on how this function
       affects the scheduling of the threads within the target process.

       If the current scheduling policy for the target process is not
       SCHED_FIFO, SCHED_RR, or SCHED_SPORADIC, the result is
       implementation-defined; this case includes the SCHED_OTHER

       The specified sched_ss_repl_period shall be greater than or equal
       to the specified sched_ss_init_budget for the function to
       succeed; if it is not, then the function shall fail.

       The value of sched_ss_max_repl shall be within the inclusive
       range [1,{SS_REPL_MAX}] for the function to succeed; if not, the
       function shall fail. It is unspecified whether the
       sched_ss_repl_period and sched_ss_init_budget values are stored
       as provided by this function or are rounded to align with the
       resolution of the clock being used.

       This function is not atomic with respect to other threads in the
       process. Threads may continue to execute while this function call
       is in the process of changing the scheduling policy for the
       underlying kernel-scheduled entities used by the process
       contention scope threads.

RETURN VALUE         top

       If successful, the sched_setparam() function shall return zero.

       If the call to sched_setparam() is unsuccessful, the priority
       shall remain unchanged, and the function shall return a value of
       -1 and set errno to indicate the error.

ERRORS         top

       The sched_setparam() function shall fail if:

       EINVAL One or more of the requested scheduling parameters is
              outside the range defined for the scheduling policy of the
              specified pid.

       EPERM  The requesting process does not have permission to set the
              scheduling parameters for the specified process, or does
              not have appropriate privileges to invoke

       ESRCH  No process can be found corresponding to that specified by

       The following sections are informative.

EXAMPLES         top




RATIONALE         top




SEE ALSO         top

       Scheduling Policies, sched_getparam(3p), sched_getscheduler(3p),

       The Base Definitions volume of POSIX.1‐2017, sched.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any
       discrepancy between this version and the original IEEE and The
       Open Group Standard, the original IEEE and The Open Group
       Standard is the referee document. The original Standard can be
       obtained online at .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see .

IEEE/The Open Group               2017                SCHED_SETPARAM(3P)

Pages that refer to this page: sched.h(0p)posix_spawn(3p)sched_getparam(3p)sched_get_priority_max(3p)sched_getscheduler(3p)sched_rr_get_interval(3p)sched_setscheduler(3p)