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60 .Nd examine or modify realtime or idle priority
67 .Fn rtprio "int function" "pid_t pid" "struct rtprio *rtp"
69 .Fn rtprio_thread "int function" "lwpid_t lwpid" "struct rtprio *rtp"
74 is used to lookup or change the realtime or idle priority of a process,
75 or the calling thread.
79 is used to lookup or change the realtime or idle priority of a thread.
84 specifies the operation to be performed.
85 RTP_LOOKUP to lookup the current priority,
86 and RTP_SET to set the priority.
94 specifies the process to operate on,
95 0 for the calling thread.
99 the system call reports the highest priority in the process,
100 or sets all threads' priority in the process,
101 depending on value of the
110 specifies the thread to operate on,
111 0 for the calling thread.
116 is a pointer to a struct rtprio which is used to specify the priority and priority type.
117 This structure has the following form:
127 field may be RTP_PRIO_REALTIME for realtime priorities,
128 RTP_PRIO_NORMAL for normal priorities, and RTP_PRIO_IDLE for idle priorities.
129 The priority specified by the
131 field ranges between 0 and
134 0 is the highest possible priority.
136 Realtime and idle priority is inherited through
141 A realtime thread can only be preempted by a thread of equal or
142 higher priority, or by an interrupt; idle priority threads will run only
143 when no other real/normal priority thread is runnable.
144 Higher real/idle priority threads
145 preempt lower real/idle priority threads.
146 Threads of equal real/idle priority are run round-robin.
148 .Rv -std rtprio rtprio_thread
158 The rtp pointer passed to
168 The calling thread is not allowed to set the priority.
170 root is allowed to change the realtime or idle priority of any thread.
171 Exceptional privileges can be granted through the
173 policy and the realtime and idletime user groups.
177 .Va security.bsd.unprivileged_idprio
179 If set to non-zero, it lets any user change the idle priority of threads
182 The specified process or thread was not found or visible.
195 The original author was
196 .An Henrik Vestergaard Draboel Aq Mt hvd@terry.ping.dk .
197 This implementation in
199 was substantially rewritten by
203 system call was implemented by