put the scheduler in its own file. reduces clutter, and logically separates

"put this process to sleep" and "find a process to run" operations.
no functional change.  ok art@

1 files changed, 1 insertions, 633 deletions

diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index 785136cd27b..fa0ff867b3c 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_synch.c,v 1.60 2004/07/25 20:50:51 tedu Exp $	*/
+/*	$OpenBSD: kern_synch.c,v 1.61 2004/07/29 06:25:45 tedu Exp $	*/
 /*	$NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $	*/
 
 /*-
@@ -52,641 +52,9 @@
 #include <sys/ktrace.h>
 #endif
 
-#include <machine/cpu.h>
-
-#ifndef __HAVE_CPUINFO
-u_char	curpriority;		/* usrpri of curproc */
-#endif
-int	lbolt;			/* once a second sleep address */
-#ifdef __HAVE_CPUINFO
-int	rrticks_init;		/* # of hardclock ticks per roundrobin() */
-#endif
-
-int whichqs;			/* Bit mask summary of non-empty Q's. */
-struct prochd qs[NQS];
-
-struct SIMPLELOCK sched_lock;
-
-void scheduler_start(void);
-
-#ifdef __HAVE_CPUINFO
-void roundrobin(struct cpu_info *);
-#else
-void roundrobin(void *);
-#endif
-void schedcpu(void *);
 void updatepri(struct proc *);
 void endtsleep(void *);
 
-void
-scheduler_start()
-{
-#ifndef __HAVE_CPUINFO
-	static struct timeout roundrobin_to;
-#endif
-	static struct timeout schedcpu_to;
-
-	/*
-	 * We avoid polluting the global namespace by keeping the scheduler
-	 * timeouts static in this function.
-	 * We setup the timeouts here and kick schedcpu and roundrobin once to
-	 * make them do their job.
-	 */
-
-#ifndef __HAVE_CPUINFO
-	timeout_set(&roundrobin_to, roundrobin, &roundrobin_to);
-#endif
-	timeout_set(&schedcpu_to, schedcpu, &schedcpu_to);
-
-#ifdef __HAVE_CPUINFO
-	rrticks_init = hz / 10;
-#else
-	roundrobin(&roundrobin_to);
-#endif
-	schedcpu(&schedcpu_to);
-}
-
-/*
- * Force switch among equal priority processes every 100ms.
- */
-/* ARGSUSED */
-#ifdef __HAVE_CPUINFO
-void
-roundrobin(struct cpu_info *ci)
-{
-	struct schedstate_percpu *spc = &ci->ci_schedstate;
-	int s;
-
-	spc->spc_rrticks = rrticks_init;
-
-	if (curproc != NULL) {
-		s = splstatclock();
-		if (spc->spc_schedflags & SPCF_SEENRR) {
-			/*
-			 * The process has already been through a roundrobin
-			 * without switching and may be hogging the CPU.
-			 * Indicate that the process should yield.
-			 */
-			spc->spc_schedflags |= SPCF_SHOULDYIELD;
-		} else {
-			spc->spc_schedflags |= SPCF_SEENRR;
-		}
-		splx(s);
-	}
-
-	need_resched(curcpu());
-}
-#else
-void
-roundrobin(void *arg)
-{
-	struct timeout *to = (struct timeout *)arg;
-	struct proc *p = curproc;
-	int s;
-
-	if (p != NULL) {
-		s = splstatclock();
-		if (p->p_schedflags & PSCHED_SEENRR) {
-			/*
-			 * The process has already been through a roundrobin
-			 * without switching and may be hogging the CPU.
-			 * Indicate that the process should yield.
-			 */
-			p->p_schedflags |= PSCHED_SHOULDYIELD;
-		} else {
-			p->p_schedflags |= PSCHED_SEENRR;
-		}
-		splx(s);
-	}
-
-	need_resched(0);
-	timeout_add(to, hz / 10);
-}
-#endif
-
-/*
- * Constants for digital decay and forget:
- *	90% of (p_estcpu) usage in 5 * loadav time
- *	95% of (p_pctcpu) usage in 60 seconds (load insensitive)
- *          Note that, as ps(1) mentions, this can let percentages
- *          total over 100% (I've seen 137.9% for 3 processes).
- *
- * Note that hardclock updates p_estcpu and p_cpticks independently.
- *
- * We wish to decay away 90% of p_estcpu in (5 * loadavg) seconds.
- * That is, the system wants to compute a value of decay such
- * that the following for loop:
- * 	for (i = 0; i < (5 * loadavg); i++)
- * 		p_estcpu *= decay;
- * will compute
- * 	p_estcpu *= 0.1;
- * for all values of loadavg:
- *
- * Mathematically this loop can be expressed by saying:
- * 	decay ** (5 * loadavg) ~= .1
- *
- * The system computes decay as:
- * 	decay = (2 * loadavg) / (2 * loadavg + 1)
- *
- * We wish to prove that the system's computation of decay
- * will always fulfill the equation:
- * 	decay ** (5 * loadavg) ~= .1
- *
- * If we compute b as:
- * 	b = 2 * loadavg
- * then
- * 	decay = b / (b + 1)
- *
- * We now need to prove two things:
- *	1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1)
- *	2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg)
- *	
- * Facts:
- *         For x close to zero, exp(x) =~ 1 + x, since
- *              exp(x) = 0! + x**1/1! + x**2/2! + ... .
- *              therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b.
- *         For x close to zero, ln(1+x) =~ x, since
- *              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).
- *         ln(.1) =~ -2.30
- *
- * Proof of (1):
- *    Solve (factor)**(power) =~ .1 given power (5*loadav):
- *	solving for factor,
- *      ln(factor) =~ (-2.30/5*loadav), or
- *      factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) =
- *          exp(-1/b) =~ (b-1)/b =~ b/(b+1).                    QED
- *
- * Proof of (2):
- *    Solve (factor)**(power) =~ .1 given factor == (b/(b+1)):
- *	solving for power,
- *      power*ln(b/(b+1)) =~ -2.30, or
- *      power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav.  QED
- *
- * Actual power values for the implemented algorithm are as follows:
- *      loadav: 1       2       3       4
- *      power:  5.68    10.32   14.94   19.55
- */
-
-/* calculations for digital decay to forget 90% of usage in 5*loadav sec */
-#define	loadfactor(loadav)	(2 * (loadav))
-#define	decay_cpu(loadfac, cpu)	(((loadfac) * (cpu)) / ((loadfac) + FSCALE))
-
-/* decay 95% of `p_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */
-fixpt_t	ccpu = 0.95122942450071400909 * FSCALE;		/* exp(-1/20) */
-
-/*
- * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
- * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
- * 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 dont 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 */
-void
-schedcpu(arg)
-	void *arg;
-{
-	struct timeout *to = (struct timeout *)arg;
-	fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
-	struct proc *p;
-	int s;
-	unsigned int newcpu;
-	int phz;
-
-	/*
-	 * If we have a statistics clock, use that to calculate CPU
-	 * time, otherwise revert to using the profiling clock (which,
-	 * in turn, defaults to hz if there is no separate profiling
-	 * clock available)
-	 */
-	phz = stathz ? stathz : profhz;
-	KASSERT(phz);
-
-	for (p = LIST_FIRST(&allproc); p != 0; p = LIST_NEXT(p, p_list)) {
-		/*
-		 * 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 = splstatclock();	/* prevent state changes */
-		/*
-		 * p_pctcpu is only for ps.
-		 */
-#if	(FSHIFT >= CCPU_SHIFT)
-		p->p_pctcpu += (phz == 100)?
-			((fixpt_t) p->p_cpticks) << (FSHIFT - CCPU_SHIFT):
-                	100 * (((fixpt_t) p->p_cpticks)
-				<< (FSHIFT - CCPU_SHIFT)) / phz;
-#else
-		p->p_pctcpu += ((FSCALE - ccpu) *
-			(p->p_cpticks * FSCALE / phz)) >> FSHIFT;
-#endif
-		p->p_cpticks = 0;
-		newcpu = (u_int) decay_cpu(loadfac, p->p_estcpu);
-		p->p_estcpu = newcpu;
-		splx(s);
-		SCHED_LOCK(s);
-		resetpriority(p);
-		if (p->p_priority >= PUSER) {
-			if ((p != curproc) &&
-			    p->p_stat == SRUN &&
-			    (p->p_flag & P_INMEM) &&
-			    (p->p_priority / PPQ) != (p->p_usrpri / PPQ)) {
-				remrunqueue(p);
-				p->p_priority = p->p_usrpri;
-				setrunqueue(p);
-			} else
-				p->p_priority = p->p_usrpri;
-		}
-		SCHED_UNLOCK(s);
-	}
-	uvm_meter();
-	wakeup((caddr_t)&lbolt);
-	timeout_add(to, 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.
- */
-void
-updatepri(p)
-	register struct proc *p;
-{
-	register unsigned int newcpu = p->p_estcpu;
-	register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
-
-	SCHED_ASSERT_LOCKED();
-
-	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 = newcpu;
-	}
-	resetpriority(p);
-}
-
-#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
-void
-sched_unlock_idle(void)
-{
-	SIMPLE_UNLOCK(&sched_lock);
-}
-
-void
-sched_lock_idle(void)
-{
-	SIMPLE_LOCK(&sched_lock);
-}
-#endif /* MULTIPROCESSOR || LOCKDEBUG */
-
-/*
- * General yield call.  Puts the current process back on its run queue and
- * performs a voluntary context switch.
- */
-void
-yield()
-{
-	struct proc *p = curproc;
-	int s;
-
-	SCHED_LOCK(s);
-	p->p_priority = p->p_usrpri;
-	setrunqueue(p);
-	p->p_stats->p_ru.ru_nvcsw++;
-	mi_switch();
-	SCHED_ASSERT_UNLOCKED();
-	splx(s);
-}
-
-/*
- * General preemption call.  Puts the current process back on its run queue
- * and performs an involuntary context switch.  If a process is supplied,
- * we switch to that process.  Otherwise, we use the normal process selection
- * criteria.
- */
-void
-preempt(newp)
-	struct proc *newp;
-{
-	struct proc *p = curproc;
-	int s;
-
-	/*
-	 * XXX Switching to a specific process is not supported yet.
-	 */
-	if (newp != NULL)
-		panic("preempt: cpu_preempt not yet implemented");
-
-	SCHED_LOCK(s);
-	p->p_priority = p->p_usrpri;
-	p->p_stat = SRUN;
-	setrunqueue(p);
-	p->p_stats->p_ru.ru_nivcsw++;
-	mi_switch();
-	SCHED_ASSERT_UNLOCKED();
-	splx(s);
-}
-
-
-/*
- * Must be called at splstatclock() or higher.
- */
-void
-mi_switch()
-{
-	struct proc *p = curproc;	/* XXX */
-	struct rlimit *rlim;
-	struct timeval tv;
-#if defined(MULTIPROCESSOR)
-	int hold_count;
-#endif
-#ifdef __HAVE_CPUINFO
-	struct schedstate_percpu *spc = &p->p_cpu->ci_schedstate;
-#endif
-
-	SCHED_ASSERT_LOCKED();
-
-#if defined(MULTIPROCESSOR)
-	/*
-	 * Release the kernel_lock, as we are about to yield the CPU.
-	 * The scheduler lock is still held until cpu_switch()
-	 * selects a new process and removes it from the run queue.
-	 */
-	if (p->p_flag & P_BIGLOCK)
-#ifdef notyet
-		hold_count = spinlock_release_all(&kernel_lock);
-#else
-		hold_count = __mp_release_all(&kernel_lock);
-#endif
-#endif
-
-	/*
-	 * Compute the amount of time during which the current
-	 * process was running, and add that to its total so far.
-	 * XXX - use microuptime here to avoid strangeness.
-	 */
-	microuptime(&tv);
-#ifdef __HAVE_CPUINFO
-	if (timercmp(&tv, &spc->spc_runtime, <)) {
-#if 0
-		printf("uptime is not monotonic! "
-		    "tv=%lu.%06lu, runtime=%lu.%06lu\n",
-		    tv.tv_sec, tv.tv_usec, spc->spc_runtime.tv_sec,
-		    spc->spc_runtime.tv_usec);
-#endif
-	} else {
-		timersub(&tv, &spc->spc_runtime, &tv);
-		timeradd(&p->p_rtime, &tv, &p->p_rtime);
-	}
-#else
-	if (timercmp(&tv, &runtime, <)) {
-#if 0
-		printf("uptime is not monotonic! "
-		    "tv=%lu.%06lu, runtime=%lu.%06lu\n",
-		    tv.tv_sec, tv.tv_usec, runtime.tv_sec, runtime.tv_usec);
-#endif
-	} else {
-		timersub(&tv, &runtime, &tv);
-		timeradd(&p->p_rtime, &tv, &p->p_rtime);
-	}
-#endif
-
-	/*
-	 * Check if the process exceeds its cpu resource allocation.
-	 * If over max, kill it.
-	 */
-	rlim = &p->p_rlimit[RLIMIT_CPU];
-	if ((rlim_t)p->p_rtime.tv_sec >= rlim->rlim_cur) {
-		if ((rlim_t)p->p_rtime.tv_sec >= rlim->rlim_max) {
-			psignal(p, SIGKILL);
-		} else {
-			psignal(p, SIGXCPU);
-			if (rlim->rlim_cur < rlim->rlim_max)
-				rlim->rlim_cur += 5;
-		}
-	}
-
-	/*
-	 * Process is about to yield the CPU; clear the appropriate
-	 * scheduling flags.
-	 */
-#ifdef __HAVE_CPUINFO
-	spc->spc_schedflags &= ~SPCF_SWITCHCLEAR;
-#else
-	p->p_schedflags &= ~PSCHED_SWITCHCLEAR;
-#endif
-
-	/*
-	 * Pick a new current process and record its start time.
-	 */
-	uvmexp.swtch++;
-	cpu_switch(p);
-
-	/*
-	 * Make sure that MD code released the scheduler lock before
-	 * resuming us.
-	 */
-	SCHED_ASSERT_UNLOCKED();
-
-	/*
-	 * We're running again; record our new start time.  We might
-	 * be running on a new CPU now, so don't use the cache'd
-	 * schedstate_percpu pointer.
-	 */
-#ifdef __HAVE_CPUINFO
-	KDASSERT(p->p_cpu != NULL);
-	KDASSERT(p->p_cpu == curcpu());
-	microuptime(&p->p_cpu->ci_schedstate.spc_runtime);
-#else
-	microuptime(&runtime);
-#endif
-
-#if defined(MULTIPROCESSOR)
-	/*
-	 * Reacquire the kernel_lock now.  We do this after we've
-	 * released the scheduler lock to avoid deadlock, and before
-	 * we reacquire the interlock.
-	 */
-	if (p->p_flag & P_BIGLOCK)
-#ifdef notyet
-		spinlock_acquire_count(&kernel_lock, hold_count);
-#else
-		__mp_acquire_count(&kernel_lock, hold_count);
-#endif
-#endif
-}
-
-/*
- * Initialize the (doubly-linked) run queues
- * to be empty.
- */
-void
-rqinit()
-{
-	register int i;
-
-	for (i = 0; i < NQS; i++)
-		qs[i].ph_link = qs[i].ph_rlink = (struct proc *)&qs[i];
-	SIMPLE_LOCK_INIT(&sched_lock);
-}
-
-static __inline void
-resched_proc(struct proc *p, u_char pri)
-{
-#ifdef __HAVE_CPUINFO
-	struct cpu_info *ci;
-#endif
-
-	/*
-	 * XXXSMP
-	 * Since p->p_cpu persists across a context switch,
-	 * this gives us *very weak* processor affinity, in
-	 * that we notify the CPU on which the process last
-	 * ran that it should try to switch.
-	 *
-	 * This does not guarantee that the process will run on
-	 * that processor next, because another processor might
-	 * grab it the next time it performs a context switch.
-	 *
-	 * This also does not handle the case where its last
-	 * CPU is running a higher-priority process, but every
-	 * other CPU is running a lower-priority process.  There
-	 * are ways to handle this situation, but they're not
-	 * currently very pretty, and we also need to weigh the
-	 * cost of moving a process from one CPU to another.
-	 *
-	 * XXXSMP
-	 * There is also the issue of locking the other CPU's
-	 * sched state, which we currently do not do.
-	 */
-#ifdef __HAVE_CPUINFO
-	ci = (p->p_cpu != NULL) ? p->p_cpu : curcpu();
-	if (pri < ci->ci_schedstate.spc_curpriority)
-		need_resched(ci);
-#else
-	if (pri < curpriority)
-		need_resched(0);
-#endif
-}
-
-/*
- * 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;
-{
-	SCHED_ASSERT_LOCKED();
-
-	switch (p->p_stat) {
-	case 0:
-	case SRUN:
-	case SONPROC:
-	case SZOMB:
-	case SDEAD:
-	default:
-		panic("setrunnable");
-	case SSTOP:
-		/*
-		 * If we're being traced (possibly because someone attached us
-		 * while we were stopped), check for a signal from the debugger.
-		 */
-		if ((p->p_flag & P_TRACED) != 0 && p->p_xstat != 0)
-			p->p_siglist |= sigmask(p->p_xstat);
-	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);
-	if (p->p_slptime > 1)
-		updatepri(p);
-	p->p_slptime = 0;
-	if ((p->p_flag & P_INMEM) == 0)
-		wakeup((caddr_t)&proc0);
-	else
-		resched_proc(p, p->p_priority);
-}
-
-/*
- * 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;
-
-	SCHED_ASSERT_LOCKED();
-
-	newpriority = PUSER + p->p_estcpu + NICE_WEIGHT * (p->p_nice - NZERO);
-	newpriority = min(newpriority, MAXPRI);
-	p->p_usrpri = newpriority;
-	resched_proc(p, p->p_usrpri);
-}
-
-/*
- * 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
-schedclock(p)
-	struct proc *p;
-{
-	int s;
-
-	p->p_estcpu = ESTCPULIM(p->p_estcpu + 1);
-	SCHED_LOCK(s);
-	resetpriority(p);
-	SCHED_UNLOCK(s);
-	if (p->p_priority >= PUSER)
-		p->p_priority = p->p_usrpri;
-}
-
 
 /*
  * We're only looking at 7 bits of the address; everything is