lots of cleanup & clarification; runrun/aston => need_resched
SCCS-vsn: sys/kern/kern_synch.c 7.14
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
- * @(#)kern_synch.c 7.13 (Berkeley) %G%
+ * @(#)kern_synch.c 7.14 (Berkeley) %G%
#include "kernel.h"
#include "buf.h"
#include "kernel.h"
#include "buf.h"
-#include "machine/psl.h"
-#include "machine/mtpr.h"
+#include "machine/cpu.h"
/*
* Force switch among equal priority processes every 100ms.
/*
* Force switch among equal priority processes every 100ms.
timeout(roundrobin, (caddr_t)0, hz / 10);
}
timeout(roundrobin, (caddr_t)0, hz / 10);
}
* Solve (factor)**(power) =~ .1 given power (5*loadav):
* solving for factor,
* ln(factor) =~ (-2.30/5*loadav), or
* 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)) =
+ * factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) =
* exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED
*
* Proof of (2):
* exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED
*
* Proof of (2):
*/
/* calculations for digital decay to forget 90% of usage in 5*loadav sec */
*/
/* calculations for digital decay to forget 90% of usage in 5*loadav sec */
-#define get_b(loadav) (2 * (loadav))
-#define get_pcpu(b, cpu) (((b) * ((cpu) & 0377)) / ((b) + FSCALE))
+#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) */
/* decay 95% of `p_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */
fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
- register fixpt_t b = get_b(averunnable[0]);
+ register fixpt_t loadfac = loadfactor(averunnable[0]);
+ register int s;
+ register unsigned int newcpu;
wakeup((caddr_t)&lbolt);
for (p = allproc; p != NULL; p = p->p_nxt) {
wakeup((caddr_t)&lbolt);
for (p = allproc; p != NULL; p = p->p_nxt) {
- if (p->p_time != 127)
- p->p_time++;
- if (p->p_stat==SSLEEP || p->p_stat==SSTOP)
- if (p->p_slptime != 127)
- p->p_slptime++;
+ /*
+ * 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_time++;
+ 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,
p->p_pctcpu = (p->p_pctcpu * ccpu) >> FSHIFT;
/*
* If the process has slept the entire second,
(p->p_cpticks * FSCALE / hz)) >> FSHIFT;
#endif
p->p_cpticks = 0;
(p->p_cpticks * FSCALE / hz)) >> FSHIFT;
#endif
p->p_cpticks = 0;
- a = (int) get_pcpu(b, p->p_cpu) + p->p_nice;
- if (a < 0)
- a = 0;
- if (a > 255)
- a = 255;
- p->p_cpu = a;
- (void) setpri(p);
+ newcpu = (u_int) decay_cpu(loadfac, p->p_cpu) + p->p_nice;
+ p->p_cpu = min(newcpu, UCHAR_MAX);
+ setpri(p);
s = splhigh(); /* prevent state changes */
if (p->p_pri >= PUSER) {
s = splhigh(); /* prevent state changes */
if (p->p_pri >= PUSER) {
-#define PPQ (128 / NQS)
- if ((p != u.u_procp || noproc) &&
+#define PPQ (128 / NQS) /* priorities per queue */
+ if ((p != curproc || noproc) &&
p->p_stat == SRUN &&
(p->p_flag & SLOAD) &&
(p->p_pri / PPQ) != (p->p_usrpri / PPQ)) {
p->p_stat == SRUN &&
(p->p_flag & SLOAD) &&
(p->p_pri / PPQ) != (p->p_usrpri / PPQ)) {
- if (runin!=0) {
- runin = 0;
- wakeup((caddr_t)&runin);
- }
- wakeup((caddr_t)&proc[2]);
+ wakeup((caddr_t)pageproc);
timeout(schedcpu, (caddr_t)0, hz);
}
/*
* Recalculate the priority of a process after it has slept for a while.
timeout(schedcpu, (caddr_t)0, hz);
}
/*
* Recalculate the priority of a process after it has slept for a while.
+ * For all load averages >= 1 and max p_cpu of 255, sleeping for at least
+ * six times the loadfactor will decay p_cpu to zero.
*/
updatepri(p)
register struct proc *p;
{
*/
updatepri(p)
register struct proc *p;
{
- register int a = p->p_cpu & 0377;
- register fixpt_t b = get_b(averunnable[0]);
-
- p->p_slptime--; /* the first time was done in schedcpu */
- while (a && --p->p_slptime)
- a = (int) get_pcpu(b, a) /* + p->p_nice */;
- p->p_slptime = 0;
- if (a < 0)
- a = 0;
- if (a > 255)
- a = 255;
- p->p_cpu = a;
- (void) setpri(p);
+ register unsigned int newcpu = p->p_cpu;
+ register fixpt_t loadfac = loadfactor(averunnable[0]);
+
+ if (p->p_slptime > 5 * loadfac)
+ p->p_cpu = 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_cpu = min(newcpu, UCHAR_MAX);
+ }
+ setpri(p);
}
#define SQSIZE 0100 /* Must be power of 2 */
}
#define SQSIZE 0100 /* Must be power of 2 */
- register struct proc *rp;
+ register struct proc *p = curproc; /* XXX */
register struct slpque *qp;
register s;
int sig, catch = pri & PCATCH;
extern int cold;
int endtsleep();
register struct slpque *qp;
register s;
int sig, catch = pri & PCATCH;
extern int cold;
int endtsleep();
s = splhigh();
if (cold || panicstr) {
/*
s = splhigh();
if (cold || panicstr) {
/*
return (0);
}
#ifdef DIAGNOSTIC
return (0);
}
#ifdef DIAGNOSTIC
- if (chan == 0 || rp->p_stat != SRUN || rp->p_rlink)
+ if (chan == 0 || p->p_stat != SRUN || p->p_rlink)
- rp->p_wchan = chan;
- rp->p_wmesg = wmesg;
- rp->p_slptime = 0;
- rp->p_pri = pri & PRIMASK;
+ p->p_wchan = chan;
+ p->p_wmesg = wmesg;
+ p->p_slptime = 0;
+ p->p_pri = pri & PRIMASK;
qp = &slpque[HASH(chan)];
if (qp->sq_head == 0)
qp = &slpque[HASH(chan)];
if (qp->sq_head == 0)
- *qp->sq_tailp = rp;
- *(qp->sq_tailp = &rp->p_link) = 0;
+ *qp->sq_tailp = p;
+ *(qp->sq_tailp = &p->p_link) = 0;
- timeout(endtsleep, (caddr_t)rp, timo);
+ timeout(endtsleep, (caddr_t)p, timo);
- * If we stop in CURSIG/issig(), a wakeup or a SIGCONT
- * (or both) could occur while we were stopped.
+ * 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
* 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, rp->p_wchan will be 0 upon return from CURSIG.
+ * stopped, p->p_wchan will be 0 upon return from CURSIG.
- rp->p_flag |= SSINTR;
- if (sig = CURSIG(rp)) {
- if (rp->p_wchan)
- unsleep(rp);
- rp->p_stat = SRUN;
+ p->p_flag |= SSINTR;
+ if (sig = CURSIG(p)) {
+ if (p->p_wchan)
+ unsleep(p);
+ p->p_stat = SRUN;
- if (rp->p_wchan == 0) {
catch = 0;
goto resume;
}
}
catch = 0;
goto resume;
}
}
+ p->p_stats->p_ru.ru_nvcsw++;
- rp->p_flag &= ~SSINTR;
- if (rp->p_flag & STIMO) {
- rp->p_flag &= ~STIMO;
+ p->p_flag &= ~SSINTR;
+ if (p->p_flag & STIMO) {
+ p->p_flag &= ~STIMO;
if (catch == 0 || sig == 0)
return (EWOULDBLOCK);
} else if (timo)
if (catch == 0 || sig == 0)
return (EWOULDBLOCK);
} else if (timo)
- untimeout(endtsleep, (caddr_t)rp);
- if (catch && (sig != 0 || (sig = CURSIG(rp)))) {
- if (u.u_sigintr & sigmask(sig))
+ untimeout(endtsleep, (caddr_t)p);
+ if (catch && (sig != 0 || (sig = CURSIG(p)))) {
+ if (p->p_sigacts->ps_sigintr & sigmask(sig))
return (EINTR);
return (ERESTART);
}
return (EINTR);
return (ERESTART);
}
- register struct proc *rp;
+ register struct proc *p = curproc; /* XXX */
register struct slpque *qp;
register s;
extern int cold;
register struct slpque *qp;
register s;
extern int cold;
panic("old sleep");
}
#endif
panic("old sleep");
}
#endif
s = splhigh();
if (cold || panicstr) {
/*
s = splhigh();
if (cold || panicstr) {
/*
return;
}
#ifdef DIAGNOSTIC
return;
}
#ifdef DIAGNOSTIC
- if (chan==0 || rp->p_stat != SRUN || rp->p_rlink)
+ if (chan==0 || p->p_stat != SRUN || p->p_rlink)
- rp->p_wchan = chan;
- rp->p_wmesg = NULL;
- rp->p_slptime = 0;
- rp->p_pri = pri;
+ p->p_wchan = chan;
+ p->p_wmesg = NULL;
+ p->p_slptime = 0;
+ p->p_pri = pri;
qp = &slpque[HASH(chan)];
if (qp->sq_head == 0)
qp = &slpque[HASH(chan)];
if (qp->sq_head == 0)
- *qp->sq_tailp = rp;
- *(qp->sq_tailp = &rp->p_link) = 0;
- rp->p_stat = SSLEEP;
+ *qp->sq_tailp = p;
+ *(qp->sq_tailp = &p->p_link) = 0;
+ p->p_stat = SSLEEP;
+ p->p_stats->p_ru.ru_nvcsw++;
- * Wake up all processes sleeping on chan.
+ * Wakeup on "chan"; set all processes
+ * sleeping on chan to run state.
*/
wakeup(chan)
register caddr_t chan;
*/
wakeup(chan)
register caddr_t chan;
if (p->p_rlink || p->p_stat != SSLEEP && p->p_stat != SSTOP)
panic("wakeup");
#endif
if (p->p_rlink || p->p_stat != SSLEEP && p->p_stat != SSTOP)
panic("wakeup");
#endif
- if (p->p_wchan==chan) {
+ if (p->p_wchan == chan) {
p->p_wchan = 0;
*q = p->p_link;
if (qp->sq_tailp == &p->p_link)
p->p_wchan = 0;
*q = p->p_link;
if (qp->sq_tailp == &p->p_link)
/* OPTIMIZED INLINE EXPANSION OF setrun(p) */
if (p->p_slptime > 1)
updatepri(p);
/* OPTIMIZED INLINE EXPANSION OF setrun(p) */
if (p->p_slptime > 1)
updatepri(p);
p->p_stat = SRUN;
if (p->p_flag & SLOAD)
setrq(p);
p->p_stat = SRUN;
if (p->p_flag & SLOAD)
setrq(p);
* Since curpri is a usrpri,
* p->p_pri is always better than curpri.
*/
* Since curpri is a usrpri,
* p->p_pri is always better than curpri.
*/
- runrun++;
- aston();
- if ((p->p_flag&SLOAD) == 0) {
- if (runout != 0) {
- runout = 0;
- wakeup((caddr_t)&runout);
- }
- wantin++;
- }
+ if ((p->p_flag&SLOAD) == 0)
+ wakeup((caddr_t)&proc0);
+ else
+ need_resched();
/* END INLINE EXPANSION */
goto restart;
}
/* END INLINE EXPANSION */
goto restart;
}
- * Set the process running;
- * arrange for it to be swapped in if necessary.
+ * 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.
*/
setrun(p)
register struct proc *p;
*/
setrun(p)
register struct proc *p;
splx(s);
if (p->p_slptime > 1)
updatepri(p);
splx(s);
if (p->p_slptime > 1)
updatepri(p);
- if (p->p_pri < curpri) {
- runrun++;
- aston();
- }
- if ((p->p_flag&SLOAD) == 0) {
- if (runout != 0) {
- runout = 0;
- wakeup((caddr_t)&runout);
- }
- wantin++;
- }
+ p->p_slptime = 0;
+ if ((p->p_flag&SLOAD) == 0)
+ wakeup((caddr_t)&proc0);
+ else if (p->p_pri < curpri)
+ need_resched();
- * Set user priority.
- * The rescheduling flag (runrun)
- * is set if the priority is better
- * than the currently running process.
+ * Compute priority of process when running in user mode.
+ * Arrange to reschedule if the resulting priority
+ * is better than that of the current process.
-setpri(pp)
- register struct proc *pp;
+setpri(p)
+ register struct proc *p;
- register int p;
-
- p = (pp->p_cpu & 0377)/4;
- p += PUSER + 2 * pp->p_nice;
- if (p > 127)
- p = 127;
- if (p < curpri) {
- runrun++;
- aston();
- }
- pp->p_usrpri = p;
- return (p);
+ register unsigned int newpri;
+
+ newpri = PUSER + p->p_cpu / 4 + 2 * p->p_nice;
+ newpri = min(newpri, MAXPRI);
+ p->p_usrpri = newpri;
+ if (newpri < curpri)
+ need_resched();