731 lines
20 KiB
C
731 lines
20 KiB
C
/* $NetBSD: sched_4bsd.c,v 1.3 2007/07/09 21:10:55 ad Exp $ */
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/*-
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* Copyright (c) 1999, 2000, 2004, 2006, 2007 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
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* NASA Ames Research Center, by Charles M. Hannum, Andrew Doran, and
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* Daniel Sieger.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*-
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* Copyright (c) 1982, 1986, 1990, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)kern_synch.c 8.9 (Berkeley) 5/19/95
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: sched_4bsd.c,v 1.3 2007/07/09 21:10:55 ad Exp $");
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#include "opt_ddb.h"
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#include "opt_lockdebug.h"
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#include "opt_perfctrs.h"
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#define __MUTEX_PRIVATE
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/callout.h>
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#include <sys/cpu.h>
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#include <sys/proc.h>
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#include <sys/kernel.h>
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#include <sys/signalvar.h>
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#include <sys/resourcevar.h>
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#include <sys/sched.h>
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#include <sys/sysctl.h>
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#include <sys/kauth.h>
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#include <sys/lockdebug.h>
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#include <sys/kmem.h>
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#include <uvm/uvm_extern.h>
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/*
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* Run queues.
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*
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* We have 32 run queues in descending priority of 0..31. We maintain
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* a bitmask of non-empty queues in order speed up finding the first
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* runnable process. The bitmask is maintained only by machine-dependent
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* code, allowing the most efficient instructions to be used to find the
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* first non-empty queue.
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*/
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#define RUNQUE_NQS 32 /* number of runqueues */
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#define PPQ (128 / RUNQUE_NQS) /* priorities per queue */
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typedef struct subqueue {
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TAILQ_HEAD(, lwp) sq_queue;
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} subqueue_t;
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typedef struct runqueue {
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subqueue_t rq_subqueues[RUNQUE_NQS]; /* run queues */
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uint32_t rq_bitmap; /* bitmap of non-empty queues */
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} runqueue_t;
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static runqueue_t global_queue;
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static void updatepri(struct lwp *);
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static void resetpriority(struct lwp *);
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static void resetprocpriority(struct proc *);
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extern unsigned int sched_pstats_ticks; /* defined in kern_synch.c */
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/* The global scheduler state */
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kmutex_t sched_mutex;
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/* Number of hardclock ticks per sched_tick() */
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int rrticks;
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/*
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* Force switch among equal priority processes every 100ms.
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* Called from hardclock every hz/10 == rrticks hardclock ticks.
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*/
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/* ARGSUSED */
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void
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sched_tick(struct cpu_info *ci)
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{
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struct schedstate_percpu *spc = &ci->ci_schedstate;
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spc->spc_ticks = rrticks;
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if (!CURCPU_IDLE_P()) {
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if (spc->spc_flags & SPCF_SEENRR) {
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/*
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* The process has already been through a roundrobin
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* without switching and may be hogging the CPU.
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* Indicate that the process should yield.
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*/
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spc->spc_flags |= SPCF_SHOULDYIELD;
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} else
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spc->spc_flags |= SPCF_SEENRR;
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}
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cpu_need_resched(curcpu(), 0);
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}
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#define NICE_WEIGHT 2 /* priorities per nice level */
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#define ESTCPU_SHIFT 11
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#define ESTCPU_MAX ((NICE_WEIGHT * PRIO_MAX - PPQ) << ESTCPU_SHIFT)
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#define ESTCPULIM(e) min((e), ESTCPU_MAX)
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/*
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* Constants for digital decay and forget:
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* 90% of (p_estcpu) usage in 5 * loadav time
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* 95% of (p_pctcpu) usage in 60 seconds (load insensitive)
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* Note that, as ps(1) mentions, this can let percentages
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* total over 100% (I've seen 137.9% for 3 processes).
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*
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* Note that hardclock updates p_estcpu and p_cpticks independently.
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*
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* We wish to decay away 90% of p_estcpu in (5 * loadavg) seconds.
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* That is, the system wants to compute a value of decay such
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* that the following for loop:
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* for (i = 0; i < (5 * loadavg); i++)
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* p_estcpu *= decay;
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* will compute
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* p_estcpu *= 0.1;
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* for all values of loadavg:
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*
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* Mathematically this loop can be expressed by saying:
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* decay ** (5 * loadavg) ~= .1
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*
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* The system computes decay as:
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* decay = (2 * loadavg) / (2 * loadavg + 1)
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*
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* We wish to prove that the system's computation of decay
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* will always fulfill the equation:
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* decay ** (5 * loadavg) ~= .1
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*
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* If we compute b as:
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* b = 2 * loadavg
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* then
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* decay = b / (b + 1)
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*
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* We now need to prove two things:
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* 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1)
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* 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg)
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*
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* Facts:
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* For x close to zero, exp(x) =~ 1 + x, since
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* exp(x) = 0! + x**1/1! + x**2/2! + ... .
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* therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b.
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* For x close to zero, ln(1+x) =~ x, since
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* ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1
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* therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1).
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* ln(.1) =~ -2.30
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*
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* Proof of (1):
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* Solve (factor)**(power) =~ .1 given power (5*loadav):
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* solving for factor,
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* ln(factor) =~ (-2.30/5*loadav), or
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* factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) =
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* exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED
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*
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* Proof of (2):
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* Solve (factor)**(power) =~ .1 given factor == (b/(b+1)):
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* solving for power,
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* power*ln(b/(b+1)) =~ -2.30, or
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* power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED
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*
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* Actual power values for the implemented algorithm are as follows:
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* loadav: 1 2 3 4
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* power: 5.68 10.32 14.94 19.55
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*/
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/* calculations for digital decay to forget 90% of usage in 5*loadav sec */
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#define loadfactor(loadav) (2 * (loadav))
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static fixpt_t
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decay_cpu(fixpt_t loadfac, fixpt_t estcpu)
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{
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if (estcpu == 0) {
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return 0;
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}
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#if !defined(_LP64)
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/* avoid 64bit arithmetics. */
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#define FIXPT_MAX ((fixpt_t)((UINTMAX_C(1) << sizeof(fixpt_t) * CHAR_BIT) - 1))
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if (__predict_true(loadfac <= FIXPT_MAX / ESTCPU_MAX)) {
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return estcpu * loadfac / (loadfac + FSCALE);
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}
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#endif /* !defined(_LP64) */
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return (uint64_t)estcpu * loadfac / (loadfac + FSCALE);
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}
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/*
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* For all load averages >= 1 and max p_estcpu of (255 << ESTCPU_SHIFT),
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* sleeping for at least seven times the loadfactor will decay p_estcpu to
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* less than (1 << ESTCPU_SHIFT).
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*
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* note that our ESTCPU_MAX is actually much smaller than (255 << ESTCPU_SHIFT).
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*/
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static fixpt_t
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decay_cpu_batch(fixpt_t loadfac, fixpt_t estcpu, unsigned int n)
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{
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if ((n << FSHIFT) >= 7 * loadfac) {
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return 0;
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}
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while (estcpu != 0 && n > 1) {
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estcpu = decay_cpu(loadfac, estcpu);
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n--;
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}
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return estcpu;
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}
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/*
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* sched_pstats_hook:
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*
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* Periodically called from sched_pstats(); used to recalculate priorities.
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*/
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void
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sched_pstats_hook(struct proc *p, int minslp)
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{
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struct lwp *l;
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fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
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/*
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* If the process has slept the entire second,
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* stop recalculating its priority until it wakes up.
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*/
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if (minslp <= 1) {
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p->p_estcpu = decay_cpu(loadfac, p->p_estcpu);
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LIST_FOREACH(l, &p->p_lwps, l_sibling) {
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if ((l->l_flag & LW_IDLE) != 0)
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continue;
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lwp_lock(l);
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if (l->l_slptime <= 1 && l->l_priority >= PUSER)
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resetpriority(l);
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lwp_unlock(l);
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}
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}
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}
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/*
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* Recalculate the priority of a process after it has slept for a while.
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*/
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static void
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updatepri(struct lwp *l)
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{
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struct proc *p = l->l_proc;
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fixpt_t loadfac;
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KASSERT(lwp_locked(l, NULL));
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KASSERT(l->l_slptime > 1);
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loadfac = loadfactor(averunnable.ldavg[0]);
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l->l_slptime--; /* the first time was done in sched_pstats */
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/* XXX NJWLWP */
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/* XXXSMP occasionally unlocked, should be per-LWP */
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p->p_estcpu = decay_cpu_batch(loadfac, p->p_estcpu, l->l_slptime);
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resetpriority(l);
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}
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/*
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* On some architectures, it's faster to use a MSB ordering for the priorites
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* than the traditional LSB ordering.
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*/
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#define RQMASK(n) (0x00000001 << (n))
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/*
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* The primitives that manipulate the run queues. whichqs tells which
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* of the 32 queues qs have processes in them. sched_enqueue() puts processes
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* into queues, sched_dequeue removes them from queues. The running process is
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* on no queue, other processes are on a queue related to p->p_priority,
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* divided by 4 actually to shrink the 0-127 range of priorities into the 32
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* available queues.
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*/
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#ifdef RQDEBUG
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static void
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runqueue_check(const runqueue_t *rq, int whichq, struct lwp *l)
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{
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const subqueue_t * const sq = &rq->rq_subqueues[whichq];
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const uint32_t bitmap = rq->rq_bitmap;
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struct lwp *l2;
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int found = 0;
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int die = 0;
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int empty = 1;
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TAILQ_FOREACH(l2, &sq->sq_queue, l_runq) {
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if (l2->l_stat != LSRUN) {
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printf("runqueue_check[%d]: lwp %p state (%d) "
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" != LSRUN\n", whichq, l2, l2->l_stat);
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}
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if (l2 == l)
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found = 1;
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empty = 0;
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}
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if (empty && (bitmap & RQMASK(whichq)) != 0) {
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printf("runqueue_check[%d]: bit set for empty run-queue %p\n",
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whichq, rq);
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die = 1;
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} else if (!empty && (bitmap & RQMASK(whichq)) == 0) {
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printf("runqueue_check[%d]: bit clear for non-empty "
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"run-queue %p\n", whichq, rq);
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die = 1;
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}
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if (l != NULL && (bitmap & RQMASK(whichq)) == 0) {
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printf("runqueue_check[%d]: bit clear for active lwp %p\n",
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whichq, l);
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die = 1;
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}
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if (l != NULL && empty) {
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printf("runqueue_check[%d]: empty run-queue %p with "
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"active lwp %p\n", whichq, rq, l);
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die = 1;
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}
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if (l != NULL && !found) {
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printf("runqueue_check[%d]: lwp %p not in runqueue %p!",
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whichq, l, rq);
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die = 1;
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}
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if (die)
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panic("runqueue_check: inconsistency found");
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}
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#else /* RQDEBUG */
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#define runqueue_check(a, b, c) /* nothing */
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#endif /* RQDEBUG */
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static void
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runqueue_init(runqueue_t *rq)
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{
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int i;
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for (i = 0; i < RUNQUE_NQS; i++)
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TAILQ_INIT(&rq->rq_subqueues[i].sq_queue);
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}
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static void
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runqueue_enqueue(runqueue_t *rq, struct lwp *l)
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{
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subqueue_t *sq;
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const int whichq = lwp_eprio(l) / PPQ;
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KASSERT(lwp_locked(l, l->l_cpu->ci_schedstate.spc_mutex));
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runqueue_check(rq, whichq, NULL);
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rq->rq_bitmap |= RQMASK(whichq);
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sq = &rq->rq_subqueues[whichq];
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TAILQ_INSERT_TAIL(&sq->sq_queue, l, l_runq);
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runqueue_check(rq, whichq, l);
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}
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static void
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runqueue_dequeue(runqueue_t *rq, struct lwp *l)
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{
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subqueue_t *sq;
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const int whichq = lwp_eprio(l) / PPQ;
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KASSERT(lwp_locked(l, l->l_cpu->ci_schedstate.spc_mutex));
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runqueue_check(rq, whichq, l);
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KASSERT((rq->rq_bitmap & RQMASK(whichq)) != 0);
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sq = &rq->rq_subqueues[whichq];
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TAILQ_REMOVE(&sq->sq_queue, l, l_runq);
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if (TAILQ_EMPTY(&sq->sq_queue))
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rq->rq_bitmap &= ~RQMASK(whichq);
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runqueue_check(rq, whichq, NULL);
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}
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static struct lwp *
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runqueue_nextlwp(runqueue_t *rq)
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{
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const uint32_t bitmap = rq->rq_bitmap;
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int whichq;
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if (bitmap == 0) {
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return NULL;
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}
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whichq = ffs(bitmap) - 1;
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return TAILQ_FIRST(&rq->rq_subqueues[whichq].sq_queue);
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}
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#if defined(DDB)
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static void
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runqueue_print(const runqueue_t *rq, void (*pr)(const char *, ...))
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{
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const uint32_t bitmap = rq->rq_bitmap;
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struct lwp *l;
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int i, first;
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for (i = 0; i < RUNQUE_NQS; i++) {
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const subqueue_t *sq;
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first = 1;
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sq = &rq->rq_subqueues[i];
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TAILQ_FOREACH(l, &sq->sq_queue, l_runq) {
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if (first) {
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(*pr)("%c%d",
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(bitmap & RQMASK(i)) ? ' ' : '!', i);
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first = 0;
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}
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(*pr)("\t%d.%d (%s) pri=%d usrpri=%d\n",
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l->l_proc->p_pid,
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l->l_lid, l->l_proc->p_comm,
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(int)l->l_priority, (int)l->l_usrpri);
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}
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}
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}
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#endif /* defined(DDB) */
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#undef RQMASK
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/*
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* Initialize the (doubly-linked) run queues
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* to be empty.
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*/
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|
void
|
|
sched_rqinit()
|
|
{
|
|
|
|
runqueue_init(&global_queue);
|
|
mutex_init(&sched_mutex, MUTEX_SPIN, IPL_SCHED);
|
|
/* Initialize the lock pointer for lwp0 */
|
|
lwp0.l_mutex = &curcpu()->ci_schedstate.spc_lwplock;
|
|
}
|
|
|
|
void
|
|
sched_cpuattach(struct cpu_info *ci)
|
|
{
|
|
runqueue_t *rq;
|
|
|
|
ci->ci_schedstate.spc_mutex = &sched_mutex;
|
|
rq = kmem_zalloc(sizeof(*rq), KM_NOSLEEP);
|
|
runqueue_init(rq);
|
|
ci->ci_schedstate.spc_sched_info = rq;
|
|
}
|
|
|
|
void
|
|
sched_setup()
|
|
{
|
|
|
|
rrticks = hz / 10;
|
|
}
|
|
|
|
void
|
|
sched_setrunnable(struct lwp *l)
|
|
{
|
|
|
|
if (l->l_slptime > 1)
|
|
updatepri(l);
|
|
}
|
|
|
|
bool
|
|
sched_curcpu_runnable_p(void)
|
|
{
|
|
runqueue_t *rq = curcpu()->ci_schedstate.spc_sched_info;
|
|
|
|
return (global_queue.rq_bitmap | rq->rq_bitmap) != 0;
|
|
}
|
|
|
|
void
|
|
sched_nice(struct proc *chgp, int n)
|
|
{
|
|
|
|
chgp->p_nice = n;
|
|
(void)resetprocpriority(chgp);
|
|
}
|
|
|
|
/*
|
|
* Compute the priority of a process when running in user mode.
|
|
* Arrange to reschedule if the resulting priority is better
|
|
* than that of the current process.
|
|
*/
|
|
static void
|
|
resetpriority(struct lwp *l)
|
|
{
|
|
unsigned int newpriority;
|
|
struct proc *p = l->l_proc;
|
|
|
|
/* XXXSMP LOCK_ASSERT(mutex_owned(&p->p_stmutex)); */
|
|
LOCK_ASSERT(lwp_locked(l, NULL));
|
|
|
|
if ((l->l_flag & LW_SYSTEM) != 0)
|
|
return;
|
|
|
|
newpriority = PUSER + (p->p_estcpu >> ESTCPU_SHIFT) +
|
|
NICE_WEIGHT * (p->p_nice - NZERO);
|
|
newpriority = min(newpriority, MAXPRI);
|
|
lwp_changepri(l, newpriority);
|
|
}
|
|
|
|
/*
|
|
* Recompute priority for all LWPs in a process.
|
|
*/
|
|
static void
|
|
resetprocpriority(struct proc *p)
|
|
{
|
|
struct lwp *l;
|
|
|
|
KASSERT(mutex_owned(&p->p_stmutex));
|
|
|
|
LIST_FOREACH(l, &p->p_lwps, l_sibling) {
|
|
lwp_lock(l);
|
|
resetpriority(l);
|
|
lwp_unlock(l);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We adjust the priority of the current process. The priority of a process
|
|
* gets worse as it accumulates CPU time. The CPU usage estimator (p_estcpu)
|
|
* is increased here. The formula for computing priorities (in kern_synch.c)
|
|
* will compute a different value each time p_estcpu increases. This can
|
|
* cause a switch, but unless the priority crosses a PPQ boundary the actual
|
|
* queue will not change. The CPU usage estimator ramps up quite quickly
|
|
* when the process is running (linearly), and decays away exponentially, at
|
|
* a rate which is proportionally slower when the system is busy. The basic
|
|
* principle is that the system will 90% forget that the process used a lot
|
|
* of CPU time in 5 * loadav seconds. This causes the system to favor
|
|
* processes which haven't run much recently, and to round-robin among other
|
|
* processes.
|
|
*/
|
|
|
|
void
|
|
sched_schedclock(struct lwp *l)
|
|
{
|
|
struct proc *p = l->l_proc;
|
|
|
|
KASSERT(!CURCPU_IDLE_P());
|
|
mutex_spin_enter(&p->p_stmutex);
|
|
p->p_estcpu = ESTCPULIM(p->p_estcpu + (1 << ESTCPU_SHIFT));
|
|
lwp_lock(l);
|
|
resetpriority(l);
|
|
mutex_spin_exit(&p->p_stmutex);
|
|
if ((l->l_flag & LW_SYSTEM) == 0 && l->l_priority >= PUSER)
|
|
l->l_priority = l->l_usrpri;
|
|
lwp_unlock(l);
|
|
}
|
|
|
|
/*
|
|
* sched_proc_fork:
|
|
*
|
|
* Inherit the parent's scheduler history.
|
|
*/
|
|
void
|
|
sched_proc_fork(struct proc *parent, struct proc *child)
|
|
{
|
|
|
|
KASSERT(mutex_owned(&parent->p_smutex));
|
|
|
|
child->p_estcpu = child->p_estcpu_inherited = parent->p_estcpu;
|
|
child->p_forktime = sched_pstats_ticks;
|
|
}
|
|
|
|
/*
|
|
* sched_proc_exit:
|
|
*
|
|
* Chargeback parents for the sins of their children.
|
|
*/
|
|
void
|
|
sched_proc_exit(struct proc *parent, struct proc *child)
|
|
{
|
|
fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
|
|
fixpt_t estcpu;
|
|
|
|
/* XXX Only if parent != init?? */
|
|
|
|
mutex_spin_enter(&parent->p_stmutex);
|
|
estcpu = decay_cpu_batch(loadfac, child->p_estcpu_inherited,
|
|
sched_pstats_ticks - child->p_forktime);
|
|
if (child->p_estcpu > estcpu)
|
|
parent->p_estcpu =
|
|
ESTCPULIM(parent->p_estcpu + child->p_estcpu - estcpu);
|
|
mutex_spin_exit(&parent->p_stmutex);
|
|
}
|
|
|
|
void
|
|
sched_enqueue(struct lwp *l, bool ctxswitch)
|
|
{
|
|
|
|
if ((l->l_flag & LW_BOUND) != 0)
|
|
runqueue_enqueue(l->l_cpu->ci_schedstate.spc_sched_info, l);
|
|
else
|
|
runqueue_enqueue(&global_queue, l);
|
|
}
|
|
|
|
/*
|
|
* XXXSMP When LWP dispatch (cpu_switch()) is changed to use sched_dequeue(),
|
|
* drop of the effective priority level from kernel to user needs to be
|
|
* moved here from userret(). The assignment in userret() is currently
|
|
* done unlocked.
|
|
*/
|
|
void
|
|
sched_dequeue(struct lwp *l)
|
|
{
|
|
|
|
if ((l->l_flag & LW_BOUND) != 0)
|
|
runqueue_dequeue(l->l_cpu->ci_schedstate.spc_sched_info, l);
|
|
else
|
|
runqueue_dequeue(&global_queue, l);
|
|
}
|
|
|
|
struct lwp *
|
|
sched_nextlwp(void)
|
|
{
|
|
lwp_t *l1, *l2;
|
|
|
|
/* For now, just pick the highest priority LWP. */
|
|
l1 = runqueue_nextlwp(curcpu()->ci_schedstate.spc_sched_info);
|
|
l2 = runqueue_nextlwp(&global_queue);
|
|
|
|
if (l1 == NULL)
|
|
return l2;
|
|
if (l2 == NULL)
|
|
return l1;
|
|
if (lwp_eprio(l2) < lwp_eprio(l1))
|
|
return l2;
|
|
else
|
|
return l1;
|
|
}
|
|
|
|
/* Dummy */
|
|
void
|
|
sched_lwp_fork(struct lwp *l)
|
|
{
|
|
|
|
}
|
|
|
|
void
|
|
sched_lwp_exit(struct lwp *l)
|
|
{
|
|
|
|
}
|
|
|
|
/* SysCtl */
|
|
|
|
SYSCTL_SETUP(sysctl_sched_setup, "sysctl kern.sched subtree setup")
|
|
{
|
|
const struct sysctlnode *node = NULL;
|
|
|
|
sysctl_createv(clog, 0, NULL, NULL,
|
|
CTLFLAG_PERMANENT,
|
|
CTLTYPE_NODE, "kern", NULL,
|
|
NULL, 0, NULL, 0,
|
|
CTL_KERN, CTL_EOL);
|
|
sysctl_createv(clog, 0, NULL, &node,
|
|
CTLFLAG_PERMANENT,
|
|
CTLTYPE_NODE, "sched",
|
|
SYSCTL_DESCR("Scheduler options"),
|
|
NULL, 0, NULL, 0,
|
|
CTL_KERN, CTL_CREATE, CTL_EOL);
|
|
|
|
if (node != NULL) {
|
|
sysctl_createv(clog, 0, &node, NULL,
|
|
CTLFLAG_PERMANENT,
|
|
CTLTYPE_STRING, "name", NULL,
|
|
NULL, 0, __UNCONST("4.4BSD"), 0,
|
|
CTL_CREATE, CTL_EOL);
|
|
}
|
|
}
|
|
|
|
#if defined(DDB)
|
|
void
|
|
sched_print_runqueue(void (*pr)(const char *, ...))
|
|
{
|
|
|
|
runqueue_print(&global_queue, pr);
|
|
}
|
|
#endif /* defined(DDB) */
|