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62 .Nd examine or modify realtime or idle priority
69 .Fn rtprio "int function" "pid_t pid" "struct rtprio *rtp"
71 .Fn rtprio_thread "int function" "lwpid_t lwpid" "struct rtprio *rtp"
76 is used to lookup or change the realtime or idle priority of a process,
77 or the calling thread.
81 is used to lookup or change the realtime or idle priority of a thread.
86 specifies the operation to be performed.
87 RTP_LOOKUP to lookup the current priority,
88 and RTP_SET to set the priority.
96 specifies the process to operate on,
97 0 for the calling thread.
101 the system call reports the highest priority in the process,
102 or sets all threads' priority in the process,
103 depending on value of the
112 specifies the thread to operate on,
113 0 for the calling thread.
118 is a pointer to a struct rtprio which is used to specify the priority and priority type.
119 This structure has the following form:
129 field may be RTP_PRIO_REALTIME for realtime priorities,
130 RTP_PRIO_NORMAL for normal priorities, and RTP_PRIO_IDLE for idle priorities.
131 The priority specified by the
133 field ranges between 0 and
136 0 is the highest possible priority.
138 Realtime and idle priority is inherited through
143 A realtime thread can only be preempted by a thread of equal or
144 higher priority, or by an interrupt; idle priority threads will run only
145 when no other real/normal priority thread is runnable.
146 Higher real/idle priority threads
147 preempt lower real/idle priority threads.
148 Threads of equal real/idle priority are run round-robin.
150 .Rv -std rtprio rtprio_thread
160 The rtp pointer passed to
170 The calling thread is not allowed to set the realtime priority.
172 root is allowed to change the realtime priority of any thread, and non-root
173 may only change the idle priority of threads the user owns,
177 .Va security.bsd.unprivileged_idprio
180 The specified process or thread was not found or visible.
192 The original author was
193 .An Henrik Vestergaard Draboel Aq Mt hvd@terry.ping.dk .
194 This implementation in
196 was substantially rewritten by
200 system call was implemented by