1sched_setparam(3C)       Standard C Library Functions       sched_setparam(3C)
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NAME

6       sched_setparam - set scheduling parameters
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SYNOPSIS

9       #include <sched.h>
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11       int sched_setparam(pid_t pid, const struct sched_param *param);
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DESCRIPTION

15       The  sched_setparam()  function  sets  the scheduling parameters of the
16       process specified by pid to the values  specified  by  the  sched_param
17       structure  pointed  to by param. The value of the sched_priority member
18       in the sched_param structure is any integer within the inclusive prior‐
19       ity range for the current scheduling policy of the process specified by
20       pid. Higher numerical values for the priority represent higher  priori‐
21       ties.  If  the value of pid is negative, the behavior of the sched_set‐
22       param() function is unspecified.
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25       If a process specified by pid exists and if  the  calling  process  has
26       permission, the scheduling parameters will be set for the process whose
27       process ID is equal to pid. The real or effective user ID of the  call‐
28       ing process must match the  real or saved (from exec(2)) user ID of the
29       target process unless the effective user ID of the calling  process  is
30       0. See Intro(2).
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33       If  pid  is zero, the scheduling parameters will be set for the calling
34       process.
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37       The target process, whether it is running or not running, resumes  exe‐
38       cution  after all other runnable processes of equal or greater priority
39       have been scheduled to run.
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42       If the priority of the process specified by the  pid  argument  is  set
43       higher  than  that  of  the  lowest priority running process and if the
44       specified process is ready to run, the process  specified  by  the  pid
45       argument  preempts a lowest priority running process. Similarly, if the
46       process calling sched_setparam() sets its own priority lower than  that
47       of  one or more other non-empty process lists, then the process that is
48       the head of  the  highest  priority  list  also  preempts  the  calling
49       process.  Thus,  in  either  case,  the  originating  process might not
50       receive notification of the completion of the requested priority change
51       until the higher priority process has executed.
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RETURN VALUES

54       If successful, the sched_setparam() function returns 0.
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57       If  the  call to sched_setparam() is unsuccessful, the priority remains
58       unchanged, and the function returns −1 and sets errno to  indicate  the
59       error.
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ERRORS

62       The sched_setparam() function will fail if:
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64       EINVAL    One or more of the requested scheduling parameters is outside
65                 the range defined for the scheduling policy of the  specified
66                 pid.
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69       EPERM     The  requesting  process  does not have permission to set the
70                 scheduling parameters for the specified process, or does  not
71                 have the appropriate privilege to invoke sched_setparam().
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74       ESRCH     No  process  can  be found corresponding to that specified by
75                 pid.
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ATTRIBUTES

79       See attributes(5) for descriptions of the following attributes:
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84       ┌─────────────────────────────┬─────────────────────────────┐
85ATTRIBUTE TYPE               ATTRIBUTE VALUE              
86       ├─────────────────────────────┼─────────────────────────────┤
87       │Interface Stability          │Committed                    │
88       ├─────────────────────────────┼─────────────────────────────┤
89       │MT-Level                     │MT-Safe                      │
90       ├─────────────────────────────┼─────────────────────────────┤
91       │Standard                     │See standards(5).            │
92       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

95       Intro(2),  exec(2),  librt(3LIB),  sched.h(3HEAD),  sched_getparam(3C),
96       sched_getscheduler(3C),  sched_setscheduler(3C),  attributes(5),  stan‐
97       dards(5)
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101SunOS 5.11                        1 Apr 2008                sched_setparam(3C)
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