f2b678d4cb
runtime. p_runtime is unsigned while p_cpulimit is not, so this avoids the nasty side effect of the process getting killed when the runtime comes up "negative" due to other bugs.
769 lines
21 KiB
C
769 lines
21 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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* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
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* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
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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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* @(#)kern_synch.c 8.9 (Berkeley) 5/19/95
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* $Id: kern_synch.c,v 1.68 1998/11/26 16:49:55 bde Exp $
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*/
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|
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#include "opt_ktrace.h"
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|
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#include <sys/param.h>
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#include <sys/systm.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/vmmeter.h>
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#include <sys/sysctl.h>
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#include <vm/vm.h>
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#include <vm/vm_extern.h>
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#ifdef KTRACE
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#include <sys/uio.h>
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#include <sys/ktrace.h>
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#endif
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|
|
|
#include <machine/cpu.h>
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#ifdef SMP
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|
#include <machine/smp.h>
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#endif
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#include <machine/limits.h> /* for UCHAR_MAX = typeof(p_priority)_MAX */
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|
|
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static void rqinit __P((void *));
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SYSINIT(runqueue, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, rqinit, NULL)
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u_char curpriority; /* usrpri of curproc */
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int lbolt; /* once a second sleep address */
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|
|
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static void endtsleep __P((void *));
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static void roundrobin __P((void *arg));
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static void schedcpu __P((void *arg));
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static void updatepri __P((struct proc *p));
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|
|
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#define MAXIMUM_SCHEDULE_QUANTUM (1000000) /* arbitrary limit */
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#ifndef DEFAULT_SCHEDULE_QUANTUM
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#define DEFAULT_SCHEDULE_QUANTUM 10
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#endif
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static int quantum = DEFAULT_SCHEDULE_QUANTUM; /* default value */
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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;
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|
int new_val = quantum;
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|
|
|
new_val = quantum;
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error = sysctl_handle_int(oidp, &new_val, 0, req);
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if (error == 0) {
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if ((new_val > 0) && (new_val < MAXIMUM_SCHEDULE_QUANTUM)) {
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quantum = new_val;
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|
} else {
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|
error = EINVAL;
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|
}
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|
}
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|
return (error);
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|
}
|
|
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|
SYSCTL_PROC(_kern, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW,
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0, sizeof quantum, sysctl_kern_quantum, "I", "");
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|
|
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/* maybe_resched: Decide if you need to reschedule or not
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* taking the priorities and schedulers into account.
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*/
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|
static void maybe_resched(struct proc *chk)
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|
{
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struct proc *p = curproc; /* XXX */
|
|
|
|
/*
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* Compare priorities if the new process is on the same scheduler,
|
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* otherwise the one on the more realtimeish scheduler wins.
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*
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* XXX idle scheduler still broken because proccess stays on idle
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* scheduler during waits (such as when getting FS locks). If a
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* standard process becomes runaway cpu-bound, the system can lockup
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* due to idle-scheduler processes in wakeup never getting any cpu.
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*/
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if (p == 0 ||
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(chk->p_priority < curpriority && RTP_PRIO_BASE(p->p_rtprio.type) == RTP_PRIO_BASE(chk->p_rtprio.type)) ||
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RTP_PRIO_BASE(chk->p_rtprio.type) < RTP_PRIO_BASE(p->p_rtprio.type)
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) {
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|
need_resched();
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|
}
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|
}
|
|
|
|
#define ROUNDROBIN_INTERVAL (hz / quantum)
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int roundrobin_interval(void)
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|
{
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|
return ROUNDROBIN_INTERVAL;
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|
}
|
|
|
|
/*
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|
* Force switch among equal priority processes every 100ms.
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|
*/
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|
/* ARGSUSED */
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|
static void
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|
roundrobin(arg)
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|
void *arg;
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|
{
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|
#ifndef SMP
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|
struct proc *p = curproc; /* XXX */
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#endif
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|
|
|
#ifdef SMP
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|
need_resched();
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|
forward_roundrobin();
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|
#else
|
|
if (p == 0 || RTP_PRIO_NEED_RR(p->p_rtprio.type))
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need_resched();
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#endif
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|
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|
timeout(roundrobin, NULL, ROUNDROBIN_INTERVAL);
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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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|
*
|
|
* Note that statclock() updates p_estcpu and p_cpticks asynchronously.
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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:
|
|
* 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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|
*
|
|
* Facts:
|
|
* 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
|
|
* 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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|
*
|
|
* Proof of (1):
|
|
* Solve (factor)**(power) =~ .1 given power (5*loadav):
|
|
* solving for factor,
|
|
* 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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|
*
|
|
* Proof of (2):
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|
* Solve (factor)**(power) =~ .1 given factor == (b/(b+1)):
|
|
* 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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|
*/
|
|
|
|
/* 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 `p_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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|
|
/* kernel uses `FSCALE', userland (SHOULD) use kern.fscale */
|
|
static int fscale __unused = FSCALE;
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|
SYSCTL_INT(_kern, OID_AUTO, fscale, CTLFLAG_RD, 0, FSCALE, "");
|
|
|
|
/*
|
|
* 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).
|
|
*
|
|
* To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
|
|
* 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
|
|
*
|
|
* If you don't want to bother with the faster/more-accurate formula, you
|
|
* can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
|
|
* (more general) method of calculating the %age of CPU used by a process.
|
|
*/
|
|
#define CCPU_SHIFT 11
|
|
|
|
/*
|
|
* Recompute process priorities, every hz ticks.
|
|
*/
|
|
/* ARGSUSED */
|
|
static void
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|
schedcpu(arg)
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|
void *arg;
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|
{
|
|
register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
|
|
register struct proc *p;
|
|
register int realstathz, s;
|
|
register unsigned int newcpu;
|
|
|
|
realstathz = stathz ? stathz : hz;
|
|
for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
|
|
/*
|
|
* Increment time in/out of memory and sleep time
|
|
* (if sleeping). We ignore overflow; with 16-bit int's
|
|
* (remember them?) overflow takes 45 days.
|
|
*/
|
|
p->p_swtime++;
|
|
if (p->p_stat == SSLEEP || p->p_stat == SSTOP)
|
|
p->p_slptime++;
|
|
p->p_pctcpu = (p->p_pctcpu * ccpu) >> FSHIFT;
|
|
/*
|
|
* If the process has slept the entire second,
|
|
* stop recalculating its priority until it wakes up.
|
|
*/
|
|
if (p->p_slptime > 1)
|
|
continue;
|
|
s = splhigh(); /* prevent state changes and protect run queue */
|
|
/*
|
|
* p_pctcpu is only for ps.
|
|
*/
|
|
#if (FSHIFT >= CCPU_SHIFT)
|
|
p->p_pctcpu += (realstathz == 100)?
|
|
((fixpt_t) p->p_cpticks) << (FSHIFT - CCPU_SHIFT):
|
|
100 * (((fixpt_t) p->p_cpticks)
|
|
<< (FSHIFT - CCPU_SHIFT)) / realstathz;
|
|
#else
|
|
p->p_pctcpu += ((FSCALE - ccpu) *
|
|
(p->p_cpticks * FSCALE / realstathz)) >> FSHIFT;
|
|
#endif
|
|
p->p_cpticks = 0;
|
|
newcpu = (u_int) decay_cpu(loadfac, p->p_estcpu) + p->p_nice;
|
|
p->p_estcpu = min(newcpu, UCHAR_MAX);
|
|
resetpriority(p);
|
|
if (p->p_priority >= PUSER) {
|
|
#define PPQ (128 / NQS) /* priorities per queue */
|
|
if ((p != curproc) &&
|
|
#ifdef SMP
|
|
(u_char)p->p_oncpu == 0xff && /* idle */
|
|
#endif
|
|
p->p_stat == SRUN &&
|
|
(p->p_flag & P_INMEM) &&
|
|
(p->p_priority / PPQ) != (p->p_usrpri / PPQ)) {
|
|
remrq(p);
|
|
p->p_priority = p->p_usrpri;
|
|
setrunqueue(p);
|
|
} else
|
|
p->p_priority = p->p_usrpri;
|
|
}
|
|
splx(s);
|
|
}
|
|
vmmeter();
|
|
wakeup((caddr_t)&lbolt);
|
|
timeout(schedcpu, (void *)0, hz);
|
|
}
|
|
|
|
/*
|
|
* Recalculate the priority of a process after it has slept for a while.
|
|
* For all load averages >= 1 and max p_estcpu of 255, sleeping for at
|
|
* least six times the loadfactor will decay p_estcpu to zero.
|
|
*/
|
|
static void
|
|
updatepri(p)
|
|
register struct proc *p;
|
|
{
|
|
register unsigned int newcpu = p->p_estcpu;
|
|
register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
|
|
|
|
if (p->p_slptime > 5 * loadfac)
|
|
p->p_estcpu = 0;
|
|
else {
|
|
p->p_slptime--; /* the first time was done in schedcpu */
|
|
while (newcpu && --p->p_slptime)
|
|
newcpu = (int) decay_cpu(loadfac, newcpu);
|
|
p->p_estcpu = min(newcpu, UCHAR_MAX);
|
|
}
|
|
resetpriority(p);
|
|
}
|
|
|
|
/*
|
|
* We're only looking at 7 bits of the address; everything is
|
|
* aligned to 4, lots of things are aligned to greater powers
|
|
* of 2. Shift right by 8, i.e. drop the bottom 256 worth.
|
|
*/
|
|
#define TABLESIZE 128
|
|
static TAILQ_HEAD(slpquehead, proc) slpque[TABLESIZE];
|
|
#define LOOKUP(x) (((intptr_t)(x) >> 8) & (TABLESIZE - 1))
|
|
|
|
/*
|
|
* During autoconfiguration or after a panic, a sleep will simply
|
|
* lower the priority briefly to allow interrupts, then return.
|
|
* The priority to be used (safepri) is machine-dependent, thus this
|
|
* value is initialized and maintained in the machine-dependent layers.
|
|
* This priority will typically be 0, or the lowest priority
|
|
* that is safe for use on the interrupt stack; it can be made
|
|
* higher to block network software interrupts after panics.
|
|
*/
|
|
int safepri;
|
|
|
|
void
|
|
sleepinit()
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < TABLESIZE; i++)
|
|
TAILQ_INIT(&slpque[i]);
|
|
}
|
|
|
|
/*
|
|
* General sleep call. Suspends the current process until a wakeup is
|
|
* performed on the specified identifier. The process will then be made
|
|
* runnable with the specified priority. Sleeps at most timo/hz seconds
|
|
* (0 means no timeout). If pri includes PCATCH flag, signals are checked
|
|
* before and after sleeping, else signals are not checked. Returns 0 if
|
|
* awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a
|
|
* signal needs to be delivered, ERESTART is returned if the current system
|
|
* call should be restarted if possible, and EINTR is returned if the system
|
|
* call should be interrupted by the signal (return EINTR).
|
|
*/
|
|
int
|
|
tsleep(ident, priority, wmesg, timo)
|
|
void *ident;
|
|
int priority, timo;
|
|
const char *wmesg;
|
|
{
|
|
struct proc *p = curproc;
|
|
int s, sig, catch = priority & PCATCH;
|
|
struct callout_handle thandle;
|
|
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_CSW))
|
|
ktrcsw(p->p_tracep, 1, 0);
|
|
#endif
|
|
s = splhigh();
|
|
if (cold || panicstr) {
|
|
/*
|
|
* After a panic, or during autoconfiguration,
|
|
* just give interrupts a chance, then just return;
|
|
* don't run any other procs or panic below,
|
|
* in case this is the idle process and already asleep.
|
|
*/
|
|
splx(safepri);
|
|
splx(s);
|
|
return (0);
|
|
}
|
|
#ifdef DIAGNOSTIC
|
|
if(p == NULL)
|
|
panic("tsleep1");
|
|
if (ident == NULL || p->p_stat != SRUN)
|
|
panic("tsleep");
|
|
/* XXX This is not exhaustive, just the most common case */
|
|
if ((p->p_procq.tqe_prev != NULL) && (*p->p_procq.tqe_prev == p))
|
|
panic("sleeping process already on another queue");
|
|
#endif
|
|
p->p_wchan = ident;
|
|
p->p_wmesg = wmesg;
|
|
p->p_slptime = 0;
|
|
p->p_priority = priority & PRIMASK;
|
|
TAILQ_INSERT_TAIL(&slpque[LOOKUP(ident)], p, p_procq);
|
|
if (timo)
|
|
thandle = timeout(endtsleep, (void *)p, timo);
|
|
/*
|
|
* We put ourselves on the sleep queue and start our timeout
|
|
* before calling CURSIG, as we could stop there, and a wakeup
|
|
* or a SIGCONT (or both) could occur while we were stopped.
|
|
* A SIGCONT would cause us to be marked as SSLEEP
|
|
* without resuming us, thus we must be ready for sleep
|
|
* when CURSIG is called. If the wakeup happens while we're
|
|
* stopped, p->p_wchan will be 0 upon return from CURSIG.
|
|
*/
|
|
if (catch) {
|
|
p->p_flag |= P_SINTR;
|
|
if ((sig = CURSIG(p))) {
|
|
if (p->p_wchan)
|
|
unsleep(p);
|
|
p->p_stat = SRUN;
|
|
goto resume;
|
|
}
|
|
if (p->p_wchan == 0) {
|
|
catch = 0;
|
|
goto resume;
|
|
}
|
|
} else
|
|
sig = 0;
|
|
p->p_stat = SSLEEP;
|
|
p->p_stats->p_ru.ru_nvcsw++;
|
|
mi_switch();
|
|
resume:
|
|
curpriority = p->p_usrpri;
|
|
splx(s);
|
|
p->p_flag &= ~P_SINTR;
|
|
if (p->p_flag & P_TIMEOUT) {
|
|
p->p_flag &= ~P_TIMEOUT;
|
|
if (sig == 0) {
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_CSW))
|
|
ktrcsw(p->p_tracep, 0, 0);
|
|
#endif
|
|
return (EWOULDBLOCK);
|
|
}
|
|
} else if (timo)
|
|
untimeout(endtsleep, (void *)p, thandle);
|
|
if (catch && (sig != 0 || (sig = CURSIG(p)))) {
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_CSW))
|
|
ktrcsw(p->p_tracep, 0, 0);
|
|
#endif
|
|
if (p->p_sigacts->ps_sigintr & sigmask(sig))
|
|
return (EINTR);
|
|
return (ERESTART);
|
|
}
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_CSW))
|
|
ktrcsw(p->p_tracep, 0, 0);
|
|
#endif
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Implement timeout for tsleep.
|
|
* If process hasn't been awakened (wchan non-zero),
|
|
* set timeout flag and undo the sleep. If proc
|
|
* is stopped, just unsleep so it will remain stopped.
|
|
*/
|
|
static void
|
|
endtsleep(arg)
|
|
void *arg;
|
|
{
|
|
register struct proc *p;
|
|
int s;
|
|
|
|
p = (struct proc *)arg;
|
|
s = splhigh();
|
|
if (p->p_wchan) {
|
|
if (p->p_stat == SSLEEP)
|
|
setrunnable(p);
|
|
else
|
|
unsleep(p);
|
|
p->p_flag |= P_TIMEOUT;
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Remove a process from its wait queue
|
|
*/
|
|
void
|
|
unsleep(p)
|
|
register struct proc *p;
|
|
{
|
|
int s;
|
|
|
|
s = splhigh();
|
|
if (p->p_wchan) {
|
|
TAILQ_REMOVE(&slpque[LOOKUP(p->p_wchan)], p, p_procq);
|
|
p->p_wchan = 0;
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Make all processes sleeping on the specified identifier runnable.
|
|
*/
|
|
void
|
|
wakeup(ident)
|
|
register void *ident;
|
|
{
|
|
register struct slpquehead *qp;
|
|
register struct proc *p;
|
|
int s;
|
|
|
|
s = splhigh();
|
|
qp = &slpque[LOOKUP(ident)];
|
|
restart:
|
|
for (p = qp->tqh_first; p != NULL; p = p->p_procq.tqe_next) {
|
|
#ifdef DIAGNOSTIC
|
|
if (p->p_stat != SSLEEP && p->p_stat != SSTOP)
|
|
panic("wakeup");
|
|
#endif
|
|
if (p->p_wchan == ident) {
|
|
TAILQ_REMOVE(qp, p, p_procq);
|
|
p->p_wchan = 0;
|
|
if (p->p_stat == SSLEEP) {
|
|
/* OPTIMIZED EXPANSION OF setrunnable(p); */
|
|
if (p->p_slptime > 1)
|
|
updatepri(p);
|
|
p->p_slptime = 0;
|
|
p->p_stat = SRUN;
|
|
if (p->p_flag & P_INMEM) {
|
|
setrunqueue(p);
|
|
maybe_resched(p);
|
|
} else {
|
|
p->p_flag |= P_SWAPINREQ;
|
|
wakeup((caddr_t)&proc0);
|
|
}
|
|
/* END INLINE EXPANSION */
|
|
goto restart;
|
|
}
|
|
}
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Make a process sleeping on the specified identifier runnable.
|
|
* May wake more than one process if a target prcoess is currently
|
|
* swapped out.
|
|
*/
|
|
void
|
|
wakeup_one(ident)
|
|
register void *ident;
|
|
{
|
|
register struct slpquehead *qp;
|
|
register struct proc *p;
|
|
int s;
|
|
|
|
s = splhigh();
|
|
qp = &slpque[LOOKUP(ident)];
|
|
|
|
for (p = qp->tqh_first; p != NULL; p = p->p_procq.tqe_next) {
|
|
#ifdef DIAGNOSTIC
|
|
if (p->p_stat != SSLEEP && p->p_stat != SSTOP)
|
|
panic("wakeup_one");
|
|
#endif
|
|
if (p->p_wchan == ident) {
|
|
TAILQ_REMOVE(qp, p, p_procq);
|
|
p->p_wchan = 0;
|
|
if (p->p_stat == SSLEEP) {
|
|
/* OPTIMIZED EXPANSION OF setrunnable(p); */
|
|
if (p->p_slptime > 1)
|
|
updatepri(p);
|
|
p->p_slptime = 0;
|
|
p->p_stat = SRUN;
|
|
if (p->p_flag & P_INMEM) {
|
|
setrunqueue(p);
|
|
maybe_resched(p);
|
|
break;
|
|
} else {
|
|
p->p_flag |= P_SWAPINREQ;
|
|
wakeup((caddr_t)&proc0);
|
|
}
|
|
/* END INLINE EXPANSION */
|
|
}
|
|
}
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* The machine independent parts of mi_switch().
|
|
* Must be called at splstatclock() or higher.
|
|
*/
|
|
void
|
|
mi_switch()
|
|
{
|
|
register struct proc *p = curproc; /* XXX */
|
|
register struct rlimit *rlim;
|
|
int x;
|
|
|
|
/*
|
|
* XXX this spl is almost unnecessary. It is partly to allow for
|
|
* sloppy callers that don't do it (issignal() via CURSIG() is the
|
|
* main offender). It is partly to work around a bug in the i386
|
|
* cpu_switch() (the ipl is not preserved). We ran for years
|
|
* without it. I think there was only a interrupt latency problem.
|
|
* The main caller, tsleep(), does an splx() a couple of instructions
|
|
* after calling here. The buggy caller, issignal(), usually calls
|
|
* here at spl0() and sometimes returns at splhigh(). The process
|
|
* then runs for a little too long at splhigh(). The ipl gets fixed
|
|
* when the process returns to user mode (or earlier).
|
|
*
|
|
* It would probably be better to always call here at spl0(). Callers
|
|
* are prepared to give up control to another process, so they must
|
|
* be prepared to be interrupted. The clock stuff here may not
|
|
* actually need splstatclock().
|
|
*/
|
|
x = splstatclock();
|
|
|
|
#ifdef SIMPLELOCK_DEBUG
|
|
if (p->p_simple_locks)
|
|
printf("sleep: holding simple lock\n");
|
|
#endif
|
|
/*
|
|
* Compute the amount of time during which the current
|
|
* process was running, and add that to its total so far.
|
|
*/
|
|
microuptime(&switchtime);
|
|
p->p_runtime += (switchtime.tv_usec - p->p_switchtime.tv_usec) +
|
|
(switchtime.tv_sec - p->p_switchtime.tv_sec) * (int64_t)1000000;
|
|
|
|
/*
|
|
* Check if the process exceeds its cpu resource allocation.
|
|
* If over max, kill it.
|
|
*/
|
|
if (p->p_stat != SZOMB && p->p_limit->p_cpulimit != RLIM_INFINITY &&
|
|
p->p_runtime > p->p_limit->p_cpulimit) {
|
|
rlim = &p->p_rlimit[RLIMIT_CPU];
|
|
if (p->p_runtime / (rlim_t)1000000 >= rlim->rlim_max) {
|
|
killproc(p, "exceeded maximum CPU limit");
|
|
} else {
|
|
psignal(p, SIGXCPU);
|
|
if (rlim->rlim_cur < rlim->rlim_max) {
|
|
/* XXX: we should make a private copy */
|
|
rlim->rlim_cur += 5;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Pick a new current process and record its start time.
|
|
*/
|
|
cnt.v_swtch++;
|
|
cpu_switch(p);
|
|
if (switchtime.tv_sec)
|
|
p->p_switchtime = switchtime;
|
|
else
|
|
microuptime(&p->p_switchtime);
|
|
splx(x);
|
|
}
|
|
|
|
/*
|
|
* Initialize the (doubly-linked) run queues
|
|
* to be empty.
|
|
*/
|
|
/* ARGSUSED*/
|
|
static void
|
|
rqinit(dummy)
|
|
void *dummy;
|
|
{
|
|
register int i;
|
|
|
|
for (i = 0; i < NQS; i++) {
|
|
qs[i].ph_link = qs[i].ph_rlink = (struct proc *)&qs[i];
|
|
rtqs[i].ph_link = rtqs[i].ph_rlink = (struct proc *)&rtqs[i];
|
|
idqs[i].ph_link = idqs[i].ph_rlink = (struct proc *)&idqs[i];
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Change process state to be runnable,
|
|
* placing it on the run queue if it is in memory,
|
|
* and awakening the swapper if it isn't in memory.
|
|
*/
|
|
void
|
|
setrunnable(p)
|
|
register struct proc *p;
|
|
{
|
|
register int s;
|
|
|
|
s = splhigh();
|
|
switch (p->p_stat) {
|
|
case 0:
|
|
case SRUN:
|
|
case SZOMB:
|
|
default:
|
|
panic("setrunnable");
|
|
case SSTOP:
|
|
case SSLEEP:
|
|
unsleep(p); /* e.g. when sending signals */
|
|
break;
|
|
|
|
case SIDL:
|
|
break;
|
|
}
|
|
p->p_stat = SRUN;
|
|
if (p->p_flag & P_INMEM)
|
|
setrunqueue(p);
|
|
splx(s);
|
|
if (p->p_slptime > 1)
|
|
updatepri(p);
|
|
p->p_slptime = 0;
|
|
if ((p->p_flag & P_INMEM) == 0) {
|
|
p->p_flag |= P_SWAPINREQ;
|
|
wakeup((caddr_t)&proc0);
|
|
}
|
|
else
|
|
maybe_resched(p);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
void
|
|
resetpriority(p)
|
|
register struct proc *p;
|
|
{
|
|
register unsigned int newpriority;
|
|
|
|
if (p->p_rtprio.type == RTP_PRIO_NORMAL) {
|
|
newpriority = PUSER + p->p_estcpu / 4 + 2 * p->p_nice;
|
|
newpriority = min(newpriority, MAXPRI);
|
|
p->p_usrpri = newpriority;
|
|
}
|
|
maybe_resched(p);
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static void sched_setup __P((void *dummy));
|
|
static void
|
|
sched_setup(dummy)
|
|
void *dummy;
|
|
{
|
|
/* Kick off timeout driven events by calling first time. */
|
|
roundrobin(NULL);
|
|
schedcpu(NULL);
|
|
}
|
|
SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
|
|
|