| runqueue.9 (84306) | runqueue.9 (88509) |
|---|---|
| 1.\" Copyright (c) 2000-2001 John H. Baldwin <jhb@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 7 unchanged lines hidden (view full) --- 16.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 17.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23.\" | 1.\" Copyright (c) 2000-2001 John H. Baldwin <jhb@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 7 unchanged lines hidden (view full) --- 16.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 17.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23.\" |
| 24.\" $FreeBSD: head/share/man/man9/runqueue.9 84306 2001-10-01 16:09:29Z ru $ | 24.\" $FreeBSD: head/share/man/man9/runqueue.9 88509 2001-12-26 23:14:04Z davidc $ |
| 25.\" 26.Dd November 3, 2000 27.Dt RUNQUEUE 9 28.Os 29.Sh NAME 30.Nm chooseproc , 31.Nm procrunnable , 32.Nm remrunqueue , 33.Nm setrunqueue 34.Nd manage the queue of runnable processes 35.Sh SYNOPSIS 36.In sys/param.h 37.In sys/proc.h 38.Vt "extern struct rq itqueues[]" ; 39.Vt "extern struct rq rtqueues[]" ; 40.Vt "extern struct rq queues[]" ; 41.Vt "extern struct rq idqueues[]" ; | 25.\" 26.Dd November 3, 2000 27.Dt RUNQUEUE 9 28.Os 29.Sh NAME 30.Nm chooseproc , 31.Nm procrunnable , 32.Nm remrunqueue , 33.Nm setrunqueue 34.Nd manage the queue of runnable processes 35.Sh SYNOPSIS 36.In sys/param.h 37.In sys/proc.h 38.Vt "extern struct rq itqueues[]" ; 39.Vt "extern struct rq rtqueues[]" ; 40.Vt "extern struct rq queues[]" ; 41.Vt "extern struct rq idqueues[]" ; |
| 42.Ft struct proc * 43.Fn chooseproc "void" 44.Ft u_int32_t | 42.Ft struct thread * 43.Fn choosethread "void" 44.Ft int |
| 45.Fn procrunnable "void" 46.Ft void | 45.Fn procrunnable "void" 46.Ft void |
| 47.Fn remrunqueue "struct proc *p" | 47.Fn remrunqueue "struct thread *td" |
| 48.Ft void | 48.Ft void |
| 49.Fn setrunqueue "struct proc *p" | 49.Fn setrunqueue "struct thread *td" |
| 50.Sh DESCRIPTION 51The run queue consists of four priority queues: 52.Va itqueues 53for interrupt threads, 54.Va rtqueues 55for realtime priority processes, 56.Va queues 57for time sharing processes, and --- 32 unchanged lines hidden (view full) --- 90This works because idle CPUs are not halted in SMP systems. 91If idle CPUs are halted in SMP systems, then this race condition might have 92more serious repercussions in the losing case, and 93.Fn procrunnable 94may have to require that the 95.Va sched_lock 96mutex be acquired. 97.Pp | 50.Sh DESCRIPTION 51The run queue consists of four priority queues: 52.Va itqueues 53for interrupt threads, 54.Va rtqueues 55for realtime priority processes, 56.Va queues 57for time sharing processes, and --- 32 unchanged lines hidden (view full) --- 90This works because idle CPUs are not halted in SMP systems. 91If idle CPUs are halted in SMP systems, then this race condition might have 92more serious repercussions in the losing case, and 93.Fn procrunnable 94may have to require that the 95.Va sched_lock 96mutex be acquired. 97.Pp |
| 98.Fn chooseproc 99returns the highest priority runnable process. 100If there are no runnable processes, then the idle process is returned. | 98.Fn choosethread 99returns the highest priority runnable thread. 100If there are no runnable threads, then the idle thread is returned. |
| 101This function is called by 102.Fn cpu_switch 103and 104.Fn cpu_throw | 101This function is called by 102.Fn cpu_switch 103and 104.Fn cpu_throw |
| 105to determine which process to switch to. 106.Fn chooseproc | 105to determine which thread to switch to. 106.Fn choosethread |
| 107must be called with the 108.Va sched_lock 109mutex held. 110.Pp 111.Fn setrunqueue | 107must be called with the 108.Va sched_lock 109mutex held. 110.Pp 111.Fn setrunqueue |
| 112adds the process 113.Fa p | 112adds the thread 113.Fa td |
| 114to the tail of the appropriate queue in the proper priority queue. | 114to the tail of the appropriate queue in the proper priority queue. |
| 115The process must be runnable, i.e.\& | 115The thread must be runnable, i.e.\& |
| 116.Va p_stat 117must be set to 118.Dv SRUN . 119This function must be called with the 120.Va sched_lock 121mutex held. 122.Pp 123.Fn remrunqueue | 116.Va p_stat 117must be set to 118.Dv SRUN . 119This function must be called with the 120.Va sched_lock 121mutex held. 122.Pp 123.Fn remrunqueue |
| 124removes process 125.Fa p | 124removes thread 125.Fa td |
| 126from its run queue. 127If | 126from its run queue. 127If |
| 128.Fa p | 128.Fa td |
| 129is not on a run queue, then the kernel will 130.Xr panic 9 . 131This function must be called with the 132.Va sched_lock 133mutex held. 134.Sh SEE ALSO 135.Xr cpu_switch 9 , 136.Xr scheduler 9 , 137.Xr sleepqueue 9 | 129is not on a run queue, then the kernel will 130.Xr panic 9 . 131This function must be called with the 132.Va sched_lock 133mutex held. 134.Sh SEE ALSO 135.Xr cpu_switch 9 , 136.Xr scheduler 9 , 137.Xr sleepqueue 9 |