1131 lines
30 KiB
C
1131 lines
30 KiB
C
/*-
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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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* 4. 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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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#define kse td_sched
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/ktr.h>
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#include <sys/lock.h>
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#include <sys/kthread.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/sched.h>
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#include <sys/smp.h>
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#include <sys/sysctl.h>
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#include <sys/sx.h>
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#include <machine/smp.h>
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/*
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* INVERSE_ESTCPU_WEIGHT is only suitable for statclock() frequencies in
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* the range 100-256 Hz (approximately).
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*/
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#define ESTCPULIM(e) \
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min((e), INVERSE_ESTCPU_WEIGHT * (NICE_WEIGHT * (PRIO_MAX - PRIO_MIN) - \
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RQ_PPQ) + INVERSE_ESTCPU_WEIGHT - 1)
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#ifdef SMP
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#define INVERSE_ESTCPU_WEIGHT (8 * smp_cpus)
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#else
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#define INVERSE_ESTCPU_WEIGHT 8 /* 1 / (priorities per estcpu level). */
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#endif
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#define NICE_WEIGHT 1 /* Priorities per nice level. */
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/*
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* The schedulable entity that can be given a context to run.
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* A process may have several of these. Probably one per processor
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* but posibly a few more. In this universe they are grouped
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* with a KSEG that contains the priority and niceness
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* for the group.
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*/
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struct kse {
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TAILQ_ENTRY(kse) ke_kglist; /* (*) Queue of KSEs in ke_ksegrp. */
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TAILQ_ENTRY(kse) ke_kgrlist; /* (*) Queue of KSEs in this state. */
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TAILQ_ENTRY(kse) ke_procq; /* (j/z) Run queue. */
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struct thread *ke_thread; /* (*) Active associated thread. */
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fixpt_t ke_pctcpu; /* (j) %cpu during p_swtime. */
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u_char ke_oncpu; /* (j) Which cpu we are on. */
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char ke_rqindex; /* (j) Run queue index. */
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enum {
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KES_THREAD = 0x0, /* slaved to thread state */
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KES_ONRUNQ
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} ke_state; /* (j) KSE status. */
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int ke_cpticks; /* (j) Ticks of cpu time. */
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struct runq *ke_runq; /* runq the kse is currently on */
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int ke_pinned; /* nested count of pinned to a cpu */
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};
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#define ke_proc ke_thread->td_proc
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#define ke_ksegrp ke_thread->td_ksegrp
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#define td_kse td_sched
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/* flags kept in td_flags */
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#define TDF_DIDRUN TDF_SCHED0 /* KSE actually ran. */
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#define TDF_EXIT TDF_SCHED1 /* KSE is being killed. */
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#define TDF_BOUND TDF_SCHED2
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#define ke_flags ke_thread->td_flags
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#define KEF_DIDRUN TDF_DIDRUN /* KSE actually ran. */
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#define KEF_EXIT TDF_EXIT /* KSE is being killed. */
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#define KEF_BOUND TDF_BOUND /* stuck to one CPU */
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#define SKE_RUNQ_PCPU(ke) \
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((ke)->ke_runq != 0 && (ke)->ke_runq != &runq)
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struct kg_sched {
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struct thread *skg_last_assigned; /* (j) Last thread assigned to */
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/* the system scheduler. */
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int skg_avail_opennings; /* (j) Num KSEs requested in group. */
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int skg_concurrency; /* (j) Num KSEs requested in group. */
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int skg_runq_kses; /* (j) Num KSEs on runq. */
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};
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#define kg_last_assigned kg_sched->skg_last_assigned
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#define kg_avail_opennings kg_sched->skg_avail_opennings
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#define kg_concurrency kg_sched->skg_concurrency
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#define kg_runq_kses kg_sched->skg_runq_kses
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/*
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* KSE_CAN_MIGRATE macro returns true if the kse can migrate between
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* cpus.
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*/
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#define KSE_CAN_MIGRATE(ke) \
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((ke)->ke_pinned == 0 && ((ke)->ke_flags & KEF_BOUND) == 0)
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static struct kse kse0;
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static struct kg_sched kg_sched0;
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static int sched_tdcnt; /* Total runnable threads in the system. */
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static int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
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#define SCHED_QUANTUM (hz / 10) /* Default sched quantum */
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static struct callout roundrobin_callout;
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static void slot_fill(struct ksegrp *kg);
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static struct kse *sched_choose(void); /* XXX Should be thread * */
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static void setup_runqs(void);
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static void roundrobin(void *arg);
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static void schedcpu(void);
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static void schedcpu_thread(void);
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static void sched_setup(void *dummy);
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static void maybe_resched(struct thread *td);
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static void updatepri(struct ksegrp *kg);
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static void resetpriority(struct ksegrp *kg);
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#ifdef SMP
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static int forward_wakeup(int cpunum);
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#endif
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static struct kproc_desc sched_kp = {
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"schedcpu",
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schedcpu_thread,
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NULL
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};
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SYSINIT(schedcpu, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, kproc_start, &sched_kp)
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SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL)
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/*
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* Global run queue.
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*/
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static struct runq runq;
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#ifdef SMP
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/*
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* Per-CPU run queues
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*/
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static struct runq runq_pcpu[MAXCPU];
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#endif
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static void
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setup_runqs(void)
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{
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#ifdef SMP
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int i;
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for (i = 0; i < MAXCPU; ++i)
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runq_init(&runq_pcpu[i]);
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#endif
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runq_init(&runq);
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}
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static int
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sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
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{
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int error, new_val;
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new_val = sched_quantum * tick;
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error = sysctl_handle_int(oidp, &new_val, 0, req);
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if (error != 0 || req->newptr == NULL)
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return (error);
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if (new_val < tick)
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return (EINVAL);
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sched_quantum = new_val / tick;
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hogticks = 2 * sched_quantum;
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return (0);
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}
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SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RD, 0, "Scheduler");
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SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "4BSD", 0,
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"Scheduler name");
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SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT | CTLFLAG_RW,
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0, sizeof sched_quantum, sysctl_kern_quantum, "I",
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"Roundrobin scheduling quantum in microseconds");
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#ifdef SMP
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/* Enable forwarding of wakeups to all other cpus */
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SYSCTL_NODE(_kern_sched, OID_AUTO, ipiwakeup, CTLFLAG_RD, NULL, "Kernel SMP");
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static int forward_wakeup_enabled = 1;
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SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, enabled, CTLFLAG_RW,
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&forward_wakeup_enabled, 0,
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"Forwarding of wakeup to idle CPUs");
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static int forward_wakeups_requested = 0;
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SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, requested, CTLFLAG_RD,
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&forward_wakeups_requested, 0,
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"Requests for Forwarding of wakeup to idle CPUs");
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static int forward_wakeups_delivered = 0;
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SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, delivered, CTLFLAG_RD,
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&forward_wakeups_delivered, 0,
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"Completed Forwarding of wakeup to idle CPUs");
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static int forward_wakeup_use_mask = 1;
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SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, usemask, CTLFLAG_RW,
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&forward_wakeup_use_mask, 0,
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"Use the mask of idle cpus");
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static int forward_wakeup_use_loop = 0;
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SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, useloop, CTLFLAG_RW,
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&forward_wakeup_use_loop, 0,
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"Use a loop to find idle cpus");
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static int forward_wakeup_use_single = 0;
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SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, onecpu, CTLFLAG_RW,
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&forward_wakeup_use_single, 0,
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"Only signal one idle cpu");
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static int forward_wakeup_use_htt = 0;
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SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, htt2, CTLFLAG_RW,
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&forward_wakeup_use_htt, 0,
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"account for htt");
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#endif
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/*
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* Arrange to reschedule if necessary, taking the priorities and
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* schedulers into account.
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*/
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static void
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maybe_resched(struct thread *td)
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{
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mtx_assert(&sched_lock, MA_OWNED);
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if (td->td_priority < curthread->td_priority)
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curthread->td_flags |= TDF_NEEDRESCHED;
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}
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/*
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* Force switch among equal priority processes every 100ms.
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* We don't actually need to force a context switch of the current process.
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* The act of firing the event triggers a context switch to softclock() and
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* then switching back out again which is equivalent to a preemption, thus
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* no further work is needed on the local CPU.
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*/
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/* ARGSUSED */
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static void
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roundrobin(void *arg)
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{
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#ifdef SMP
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mtx_lock_spin(&sched_lock);
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forward_roundrobin();
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mtx_unlock_spin(&sched_lock);
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#endif
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callout_reset(&roundrobin_callout, sched_quantum, roundrobin, NULL);
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}
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/*
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* Constants for digital decay and forget:
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* 90% of (kg_estcpu) usage in 5 * loadav time
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* 95% of (ke_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 schedclock() updates kg_estcpu and p_cpticks asynchronously.
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*
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* We wish to decay away 90% of kg_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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* kg_estcpu *= decay;
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* will compute
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* kg_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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#define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE))
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/* decay 95% of `ke_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */
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static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
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SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
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/*
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* If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
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* faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
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* and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT).
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*
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* To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
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* 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
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*
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* If you don't want to bother with the faster/more-accurate formula, you
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* can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
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* (more general) method of calculating the %age of CPU used by a process.
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*/
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#define CCPU_SHIFT 11
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/*
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* Recompute process priorities, every hz ticks.
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* MP-safe, called without the Giant mutex.
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*/
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/* ARGSUSED */
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static void
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schedcpu(void)
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{
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register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
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struct thread *td;
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struct proc *p;
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struct kse *ke;
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struct ksegrp *kg;
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int awake, realstathz;
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realstathz = stathz ? stathz : hz;
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sx_slock(&allproc_lock);
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FOREACH_PROC_IN_SYSTEM(p) {
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/*
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* Prevent state changes and protect run queue.
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*/
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mtx_lock_spin(&sched_lock);
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/*
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* Increment time in/out of memory. We ignore overflow; with
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* 16-bit int's (remember them?) overflow takes 45 days.
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*/
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p->p_swtime++;
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FOREACH_KSEGRP_IN_PROC(p, kg) {
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awake = 0;
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FOREACH_THREAD_IN_GROUP(kg, td) {
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ke = td->td_kse;
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/*
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* Increment sleep time (if sleeping). We
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* ignore overflow, as above.
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*/
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/*
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* The kse slptimes are not touched in wakeup
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* because the thread may not HAVE a KSE.
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*/
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if (ke->ke_state == KES_ONRUNQ) {
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awake = 1;
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ke->ke_flags &= ~KEF_DIDRUN;
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} else if ((ke->ke_state == KES_THREAD) &&
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(TD_IS_RUNNING(td))) {
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awake = 1;
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/* Do not clear KEF_DIDRUN */
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} else if (ke->ke_flags & KEF_DIDRUN) {
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awake = 1;
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ke->ke_flags &= ~KEF_DIDRUN;
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}
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/*
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* ke_pctcpu is only for ps and ttyinfo().
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* Do it per kse, and add them up at the end?
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* XXXKSE
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*/
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ke->ke_pctcpu = (ke->ke_pctcpu * ccpu) >>
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FSHIFT;
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/*
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* If the kse has been idle the entire second,
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* stop recalculating its priority until
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* it wakes up.
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*/
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if (ke->ke_cpticks == 0)
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continue;
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#if (FSHIFT >= CCPU_SHIFT)
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ke->ke_pctcpu += (realstathz == 100)
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? ((fixpt_t) ke->ke_cpticks) <<
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(FSHIFT - CCPU_SHIFT) :
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100 * (((fixpt_t) ke->ke_cpticks)
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<< (FSHIFT - CCPU_SHIFT)) / realstathz;
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#else
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ke->ke_pctcpu += ((FSCALE - ccpu) *
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(ke->ke_cpticks *
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FSCALE / realstathz)) >> FSHIFT;
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#endif
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ke->ke_cpticks = 0;
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} /* end of kse loop */
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/*
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* If there are ANY running threads in this KSEGRP,
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* then don't count it as sleeping.
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*/
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if (awake) {
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if (kg->kg_slptime > 1) {
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/*
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|
* In an ideal world, this should not
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* happen, because whoever woke us
|
|
* up from the long sleep should have
|
|
* unwound the slptime and reset our
|
|
* priority before we run at the stale
|
|
* priority. Should KASSERT at some
|
|
* point when all the cases are fixed.
|
|
*/
|
|
updatepri(kg);
|
|
}
|
|
kg->kg_slptime = 0;
|
|
} else
|
|
kg->kg_slptime++;
|
|
if (kg->kg_slptime > 1)
|
|
continue;
|
|
kg->kg_estcpu = decay_cpu(loadfac, kg->kg_estcpu);
|
|
resetpriority(kg);
|
|
FOREACH_THREAD_IN_GROUP(kg, td) {
|
|
if (td->td_priority >= PUSER) {
|
|
sched_prio(td, kg->kg_user_pri);
|
|
}
|
|
}
|
|
} /* end of ksegrp loop */
|
|
mtx_unlock_spin(&sched_lock);
|
|
} /* end of process loop */
|
|
sx_sunlock(&allproc_lock);
|
|
}
|
|
|
|
/*
|
|
* Main loop for a kthread that executes schedcpu once a second.
|
|
*/
|
|
static void
|
|
schedcpu_thread(void)
|
|
{
|
|
int nowake;
|
|
|
|
for (;;) {
|
|
schedcpu();
|
|
tsleep(&nowake, curthread->td_priority, "-", hz);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Recalculate the priority of a process after it has slept for a while.
|
|
* For all load averages >= 1 and max kg_estcpu of 255, sleeping for at
|
|
* least six times the loadfactor will decay kg_estcpu to zero.
|
|
*/
|
|
static void
|
|
updatepri(struct ksegrp *kg)
|
|
{
|
|
register fixpt_t loadfac;
|
|
register unsigned int newcpu;
|
|
|
|
loadfac = loadfactor(averunnable.ldavg[0]);
|
|
if (kg->kg_slptime > 5 * loadfac)
|
|
kg->kg_estcpu = 0;
|
|
else {
|
|
newcpu = kg->kg_estcpu;
|
|
kg->kg_slptime--; /* was incremented in schedcpu() */
|
|
while (newcpu && --kg->kg_slptime)
|
|
newcpu = decay_cpu(loadfac, newcpu);
|
|
kg->kg_estcpu = newcpu;
|
|
}
|
|
resetpriority(kg);
|
|
}
|
|
|
|
/*
|
|
* 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 ksegrp *kg)
|
|
{
|
|
register unsigned int newpriority;
|
|
struct thread *td;
|
|
|
|
if (kg->kg_pri_class == PRI_TIMESHARE) {
|
|
newpriority = PUSER + kg->kg_estcpu / INVERSE_ESTCPU_WEIGHT +
|
|
NICE_WEIGHT * (kg->kg_proc->p_nice - PRIO_MIN);
|
|
newpriority = min(max(newpriority, PRI_MIN_TIMESHARE),
|
|
PRI_MAX_TIMESHARE);
|
|
kg->kg_user_pri = newpriority;
|
|
}
|
|
FOREACH_THREAD_IN_GROUP(kg, td) {
|
|
maybe_resched(td); /* XXXKSE silly */
|
|
}
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static void
|
|
sched_setup(void *dummy)
|
|
{
|
|
setup_runqs();
|
|
|
|
if (sched_quantum == 0)
|
|
sched_quantum = SCHED_QUANTUM;
|
|
hogticks = 2 * sched_quantum;
|
|
|
|
callout_init(&roundrobin_callout, CALLOUT_MPSAFE);
|
|
|
|
/* Kick off timeout driven events by calling first time. */
|
|
roundrobin(NULL);
|
|
|
|
/* Account for thread0. */
|
|
sched_tdcnt++;
|
|
}
|
|
|
|
/* External interfaces start here */
|
|
/*
|
|
* Very early in the boot some setup of scheduler-specific
|
|
* parts of proc0 and of soem scheduler resources needs to be done.
|
|
* Called from:
|
|
* proc0_init()
|
|
*/
|
|
void
|
|
schedinit(void)
|
|
{
|
|
/*
|
|
* Set up the scheduler specific parts of proc0.
|
|
*/
|
|
proc0.p_sched = NULL; /* XXX */
|
|
ksegrp0.kg_sched = &kg_sched0;
|
|
thread0.td_sched = &kse0;
|
|
kse0.ke_thread = &thread0;
|
|
kse0.ke_oncpu = NOCPU; /* wrong.. can we use PCPU(cpuid) yet? */
|
|
kse0.ke_state = KES_THREAD;
|
|
kg_sched0.skg_concurrency = 1;
|
|
kg_sched0.skg_avail_opennings = 0; /* we are already running */
|
|
}
|
|
|
|
int
|
|
sched_runnable(void)
|
|
{
|
|
#ifdef SMP
|
|
return runq_check(&runq) + runq_check(&runq_pcpu[PCPU_GET(cpuid)]);
|
|
#else
|
|
return runq_check(&runq);
|
|
#endif
|
|
}
|
|
|
|
int
|
|
sched_rr_interval(void)
|
|
{
|
|
if (sched_quantum == 0)
|
|
sched_quantum = SCHED_QUANTUM;
|
|
return (sched_quantum);
|
|
}
|
|
|
|
/*
|
|
* We adjust the priority of the current process. The priority of
|
|
* a process gets worse as it accumulates CPU time. The cpu usage
|
|
* estimator (kg_estcpu) is increased here. resetpriority() will
|
|
* compute a different priority each time kg_estcpu increases by
|
|
* INVERSE_ESTCPU_WEIGHT
|
|
* (until MAXPRI is reached). 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_clock(struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
struct kse *ke;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
kg = td->td_ksegrp;
|
|
ke = td->td_kse;
|
|
|
|
ke->ke_cpticks++;
|
|
kg->kg_estcpu = ESTCPULIM(kg->kg_estcpu + 1);
|
|
if ((kg->kg_estcpu % INVERSE_ESTCPU_WEIGHT) == 0) {
|
|
resetpriority(kg);
|
|
if (td->td_priority >= PUSER)
|
|
td->td_priority = kg->kg_user_pri;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* charge childs scheduling cpu usage to parent.
|
|
*
|
|
* XXXKSE assume only one thread & kse & ksegrp keep estcpu in each ksegrp.
|
|
* Charge it to the ksegrp that did the wait since process estcpu is sum of
|
|
* all ksegrps, this is strictly as expected. Assume that the child process
|
|
* aggregated all the estcpu into the 'built-in' ksegrp.
|
|
*/
|
|
void
|
|
sched_exit(struct proc *p, struct thread *td)
|
|
{
|
|
sched_exit_ksegrp(FIRST_KSEGRP_IN_PROC(p), td);
|
|
sched_exit_thread(FIRST_THREAD_IN_PROC(p), td);
|
|
}
|
|
|
|
void
|
|
sched_exit_ksegrp(struct ksegrp *kg, struct thread *childtd)
|
|
{
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
kg->kg_estcpu = ESTCPULIM(kg->kg_estcpu + childtd->td_ksegrp->kg_estcpu);
|
|
}
|
|
|
|
void
|
|
sched_exit_thread(struct thread *td, struct thread *child)
|
|
{
|
|
if ((child->td_proc->p_flag & P_NOLOAD) == 0)
|
|
sched_tdcnt--;
|
|
}
|
|
|
|
void
|
|
sched_fork(struct thread *td, struct thread *childtd)
|
|
{
|
|
sched_fork_ksegrp(td, childtd->td_ksegrp);
|
|
sched_fork_thread(td, childtd);
|
|
}
|
|
|
|
void
|
|
sched_fork_ksegrp(struct thread *td, struct ksegrp *child)
|
|
{
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
child->kg_estcpu = td->td_ksegrp->kg_estcpu;
|
|
}
|
|
|
|
void
|
|
sched_fork_thread(struct thread *td, struct thread *childtd)
|
|
{
|
|
sched_newthread(childtd);
|
|
}
|
|
|
|
void
|
|
sched_nice(struct proc *p, int nice)
|
|
{
|
|
struct ksegrp *kg;
|
|
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
p->p_nice = nice;
|
|
FOREACH_KSEGRP_IN_PROC(p, kg) {
|
|
resetpriority(kg);
|
|
}
|
|
}
|
|
|
|
void
|
|
sched_class(struct ksegrp *kg, int class)
|
|
{
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
kg->kg_pri_class = class;
|
|
}
|
|
|
|
/*
|
|
* Adjust the priority of a thread.
|
|
* This may include moving the thread within the KSEGRP,
|
|
* changing the assignment of a kse to the thread,
|
|
* and moving a KSE in the system run queue.
|
|
*/
|
|
void
|
|
sched_prio(struct thread *td, u_char prio)
|
|
{
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
if (TD_ON_RUNQ(td)) {
|
|
adjustrunqueue(td, prio);
|
|
} else {
|
|
td->td_priority = prio;
|
|
}
|
|
}
|
|
|
|
void
|
|
sched_sleep(struct thread *td)
|
|
{
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
td->td_ksegrp->kg_slptime = 0;
|
|
td->td_base_pri = td->td_priority;
|
|
}
|
|
|
|
void
|
|
sched_switch(struct thread *td, struct thread *newtd)
|
|
{
|
|
struct kse *ke;
|
|
struct proc *p;
|
|
|
|
ke = td->td_kse;
|
|
p = td->td_proc;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
|
|
if ((p->p_flag & P_NOLOAD) == 0)
|
|
sched_tdcnt--;
|
|
if (newtd != NULL && (newtd->td_proc->p_flag & P_NOLOAD) == 0)
|
|
sched_tdcnt++;
|
|
/*
|
|
* The thread we are about to run needs to be counted as if it had been
|
|
* added to the run queue and selected.
|
|
*/
|
|
if (newtd) {
|
|
newtd->td_ksegrp->kg_avail_opennings--;
|
|
newtd->td_kse->ke_flags |= KEF_DIDRUN;
|
|
TD_SET_RUNNING(newtd);
|
|
}
|
|
td->td_lastcpu = td->td_oncpu;
|
|
td->td_flags &= ~TDF_NEEDRESCHED;
|
|
td->td_pflags &= ~TDP_OWEPREEMPT;
|
|
td->td_oncpu = NOCPU;
|
|
/*
|
|
* At the last moment, if this thread is still marked RUNNING,
|
|
* then put it back on the run queue as it has not been suspended
|
|
* or stopped or any thing else similar. We never put the idle
|
|
* threads on the run queue, however.
|
|
*/
|
|
if (td == PCPU_GET(idlethread))
|
|
TD_SET_CAN_RUN(td);
|
|
else {
|
|
td->td_ksegrp->kg_avail_opennings++;
|
|
if (TD_IS_RUNNING(td)) {
|
|
/* Put us back on the run queue (kse and all). */
|
|
setrunqueue(td, SRQ_OURSELF|SRQ_YIELDING);
|
|
} else if (p->p_flag & P_HADTHREADS) {
|
|
/*
|
|
* We will not be on the run queue. So we must be
|
|
* sleeping or similar. As it's available,
|
|
* someone else can use the KSE if they need it.
|
|
*/
|
|
slot_fill(td->td_ksegrp);
|
|
}
|
|
}
|
|
if (newtd == NULL)
|
|
newtd = choosethread();
|
|
if (td != newtd)
|
|
cpu_switch(td, newtd);
|
|
sched_lock.mtx_lock = (uintptr_t)td;
|
|
td->td_oncpu = PCPU_GET(cpuid);
|
|
}
|
|
|
|
void
|
|
sched_wakeup(struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
kg = td->td_ksegrp;
|
|
if (kg->kg_slptime > 1)
|
|
updatepri(kg);
|
|
kg->kg_slptime = 0;
|
|
setrunqueue(td, SRQ_BORING);
|
|
}
|
|
|
|
#ifdef SMP
|
|
/* enable HTT_2 if you have a 2-way HTT cpu.*/
|
|
static int
|
|
forward_wakeup(int cpunum)
|
|
{
|
|
cpumask_t map, me, dontuse;
|
|
cpumask_t map2;
|
|
struct pcpu *pc;
|
|
cpumask_t id, map3;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
|
|
CTR0(KTR_RUNQ, "forward_wakeup()");
|
|
|
|
if ((!forward_wakeup_enabled) ||
|
|
(forward_wakeup_use_mask == 0 && forward_wakeup_use_loop == 0))
|
|
return (0);
|
|
if (!smp_started || cold || panicstr)
|
|
return (0);
|
|
|
|
forward_wakeups_requested++;
|
|
|
|
/*
|
|
* check the idle mask we received against what we calculated before
|
|
* in the old version.
|
|
*/
|
|
me = PCPU_GET(cpumask);
|
|
/*
|
|
* don't bother if we should be doing it ourself..
|
|
*/
|
|
if ((me & idle_cpus_mask) && (cpunum == NOCPU || me == (1 << cpunum)))
|
|
return (0);
|
|
|
|
dontuse = me | stopped_cpus | hlt_cpus_mask;
|
|
map3 = 0;
|
|
if (forward_wakeup_use_loop) {
|
|
SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
|
|
id = pc->pc_cpumask;
|
|
if ( (id & dontuse) == 0 &&
|
|
pc->pc_curthread == pc->pc_idlethread) {
|
|
map3 |= id;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (forward_wakeup_use_mask) {
|
|
map = 0;
|
|
map = idle_cpus_mask & ~dontuse;
|
|
|
|
/* If they are both on, compare and use loop if different */
|
|
if (forward_wakeup_use_loop) {
|
|
if (map != map3) {
|
|
printf("map (%02X) != map3 (%02X)\n",
|
|
map, map3);
|
|
map = map3;
|
|
}
|
|
}
|
|
} else {
|
|
map = map3;
|
|
}
|
|
/* If we only allow a specific CPU, then mask off all the others */
|
|
if (cpunum != NOCPU) {
|
|
KASSERT((cpunum <= mp_maxcpus),("forward_wakeup: bad cpunum."));
|
|
map &= (1 << cpunum);
|
|
} else {
|
|
/* Try choose an idle die. */
|
|
if (forward_wakeup_use_htt) {
|
|
map2 = (map & (map >> 1)) & 0x5555;
|
|
if (map2) {
|
|
map = map2;
|
|
}
|
|
}
|
|
|
|
/* set only one bit */
|
|
if (forward_wakeup_use_single) {
|
|
map = map & ((~map) + 1);
|
|
}
|
|
}
|
|
if (map) {
|
|
forward_wakeups_delivered++;
|
|
ipi_selected(map, IPI_AST);
|
|
return (1);
|
|
}
|
|
if (cpunum == NOCPU)
|
|
printf("forward_wakeup: Idle processor not found\n");
|
|
return (0);
|
|
}
|
|
#endif
|
|
|
|
void
|
|
sched_add(struct thread *td, int flags)
|
|
{
|
|
struct kse *ke;
|
|
#ifdef SMP
|
|
int forwarded = 0;
|
|
int cpu;
|
|
#endif
|
|
|
|
ke = td->td_kse;
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
KASSERT(ke->ke_state != KES_ONRUNQ,
|
|
("sched_add: kse %p (%s) already in run queue", ke,
|
|
ke->ke_proc->p_comm));
|
|
KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
|
|
("sched_add: process swapped out"));
|
|
|
|
#ifdef SMP
|
|
if (KSE_CAN_MIGRATE(ke)) {
|
|
CTR2(KTR_RUNQ,
|
|
"sched_add: adding kse:%p (td:%p) to gbl runq", ke, td);
|
|
cpu = NOCPU;
|
|
ke->ke_runq = &runq;
|
|
} else {
|
|
if (!SKE_RUNQ_PCPU(ke))
|
|
ke->ke_runq = &runq_pcpu[(cpu = PCPU_GET(cpuid))];
|
|
else
|
|
cpu = td->td_lastcpu;
|
|
CTR3(KTR_RUNQ,
|
|
"sched_add: Put kse:%p(td:%p) on cpu%d runq", ke, td, cpu);
|
|
}
|
|
#else
|
|
CTR2(KTR_RUNQ, "sched_add: adding kse:%p (td:%p) to runq", ke, td);
|
|
ke->ke_runq = &runq;
|
|
|
|
#endif
|
|
/*
|
|
* If we are yielding (on the way out anyhow)
|
|
* or the thread being saved is US,
|
|
* then don't try be smart about preemption
|
|
* or kicking off another CPU
|
|
* as it won't help and may hinder.
|
|
* In the YIEDLING case, we are about to run whoever is
|
|
* being put in the queue anyhow, and in the
|
|
* OURSELF case, we are puting ourself on the run queue
|
|
* which also only happens when we are about to yield.
|
|
*/
|
|
if((flags & SRQ_YIELDING) == 0) {
|
|
#ifdef SMP
|
|
cpumask_t me = PCPU_GET(cpumask);
|
|
int idle = idle_cpus_mask & me;
|
|
/*
|
|
* Only try to kick off another CPU if
|
|
* the thread is unpinned
|
|
* or pinned to another cpu,
|
|
* and there are other available and idle CPUs.
|
|
* if we are idle, then skip straight to preemption.
|
|
*/
|
|
if ( (! idle) &&
|
|
(idle_cpus_mask & ~(hlt_cpus_mask | me)) &&
|
|
( KSE_CAN_MIGRATE(ke) ||
|
|
ke->ke_runq != &runq_pcpu[PCPU_GET(cpuid)])) {
|
|
forwarded = forward_wakeup(cpu);
|
|
}
|
|
/*
|
|
* If we failed to kick off another cpu, then look to
|
|
* see if we should preempt this CPU. Only allow this
|
|
* if it is not pinned or IS pinned to this CPU.
|
|
* If we are the idle thread, we also try do preempt.
|
|
* as it will be quicker and being idle, we won't
|
|
* lose in doing so..
|
|
*/
|
|
if ((!forwarded) &&
|
|
(ke->ke_runq == &runq ||
|
|
ke->ke_runq == &runq_pcpu[PCPU_GET(cpuid)]))
|
|
#endif
|
|
|
|
{
|
|
if (maybe_preempt(td))
|
|
return;
|
|
}
|
|
}
|
|
if ((td->td_proc->p_flag & P_NOLOAD) == 0)
|
|
sched_tdcnt++;
|
|
runq_add(ke->ke_runq, ke);
|
|
ke->ke_ksegrp->kg_runq_kses++;
|
|
ke->ke_state = KES_ONRUNQ;
|
|
maybe_resched(td);
|
|
}
|
|
|
|
void
|
|
sched_rem(struct thread *td)
|
|
{
|
|
struct kse *ke;
|
|
|
|
ke = td->td_kse;
|
|
KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
|
|
("sched_rem: process swapped out"));
|
|
KASSERT((ke->ke_state == KES_ONRUNQ),
|
|
("sched_rem: KSE not on run queue"));
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
|
|
if ((td->td_proc->p_flag & P_NOLOAD) == 0)
|
|
sched_tdcnt--;
|
|
runq_remove(ke->ke_runq, ke);
|
|
|
|
ke->ke_state = KES_THREAD;
|
|
ke->ke_ksegrp->kg_runq_kses--;
|
|
}
|
|
|
|
struct kse *
|
|
sched_choose(void)
|
|
{
|
|
struct kse *ke;
|
|
struct runq *rq;
|
|
|
|
#ifdef SMP
|
|
struct kse *kecpu;
|
|
|
|
rq = &runq;
|
|
ke = runq_choose(&runq);
|
|
kecpu = runq_choose(&runq_pcpu[PCPU_GET(cpuid)]);
|
|
|
|
if (ke == NULL ||
|
|
(kecpu != NULL &&
|
|
kecpu->ke_thread->td_priority < ke->ke_thread->td_priority)) {
|
|
CTR2(KTR_RUNQ, "choosing kse %p from pcpu runq %d", kecpu,
|
|
PCPU_GET(cpuid));
|
|
ke = kecpu;
|
|
rq = &runq_pcpu[PCPU_GET(cpuid)];
|
|
} else {
|
|
CTR1(KTR_RUNQ, "choosing kse %p from main runq", ke);
|
|
}
|
|
|
|
#else
|
|
rq = &runq;
|
|
ke = runq_choose(&runq);
|
|
#endif
|
|
|
|
if (ke != NULL) {
|
|
runq_remove(rq, ke);
|
|
ke->ke_state = KES_THREAD;
|
|
ke->ke_ksegrp->kg_runq_kses--;
|
|
|
|
KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
|
|
("sched_choose: process swapped out"));
|
|
}
|
|
return (ke);
|
|
}
|
|
|
|
void
|
|
sched_userret(struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
/*
|
|
* XXX we cheat slightly on the locking here to avoid locking in
|
|
* the usual case. Setting td_priority here is essentially an
|
|
* incomplete workaround for not setting it properly elsewhere.
|
|
* Now that some interrupt handlers are threads, not setting it
|
|
* properly elsewhere can clobber it in the window between setting
|
|
* it here and returning to user mode, so don't waste time setting
|
|
* it perfectly here.
|
|
*/
|
|
kg = td->td_ksegrp;
|
|
if (td->td_priority != kg->kg_user_pri) {
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_priority = kg->kg_user_pri;
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
}
|
|
|
|
void
|
|
sched_bind(struct thread *td, int cpu)
|
|
{
|
|
struct kse *ke;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
KASSERT(TD_IS_RUNNING(td),
|
|
("sched_bind: cannot bind non-running thread"));
|
|
|
|
ke = td->td_kse;
|
|
|
|
ke->ke_flags |= KEF_BOUND;
|
|
#ifdef SMP
|
|
ke->ke_runq = &runq_pcpu[cpu];
|
|
if (PCPU_GET(cpuid) == cpu)
|
|
return;
|
|
|
|
ke->ke_state = KES_THREAD;
|
|
|
|
mi_switch(SW_VOL, NULL);
|
|
#endif
|
|
}
|
|
|
|
void
|
|
sched_unbind(struct thread* td)
|
|
{
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
td->td_kse->ke_flags &= ~KEF_BOUND;
|
|
}
|
|
|
|
int
|
|
sched_load(void)
|
|
{
|
|
return (sched_tdcnt);
|
|
}
|
|
|
|
int
|
|
sched_sizeof_ksegrp(void)
|
|
{
|
|
return (sizeof(struct ksegrp) + sizeof(struct kg_sched));
|
|
}
|
|
int
|
|
sched_sizeof_proc(void)
|
|
{
|
|
return (sizeof(struct proc));
|
|
}
|
|
int
|
|
sched_sizeof_thread(void)
|
|
{
|
|
return (sizeof(struct thread) + sizeof(struct kse));
|
|
}
|
|
|
|
fixpt_t
|
|
sched_pctcpu(struct thread *td)
|
|
{
|
|
struct kse *ke;
|
|
|
|
ke = td->td_kse;
|
|
return (ke->ke_pctcpu);
|
|
|
|
return (0);
|
|
}
|
|
#define KERN_SWITCH_INCLUDE 1
|
|
#include "kern/kern_switch.c"
|