5 files changed, 42 insertions, 35 deletions

diff --git a/sys/src/9/port/edf.c b/sys/src/9/port/edf.c
index a9fc4b854..99bbf1f61 100644
--- a/sys/src/9/port/edf.c
+++ b/sys/src/9/port/edf.c
@@ -207,7 +207,7 @@ release(Proc *p)
 }
 
 static void
-releaseintr(Ureg*, Timer *t)
+releaseintr(Ureg *u, Timer *t)
 {
 	Proc *p;
 	extern int panicking;
@@ -254,9 +254,7 @@ releaseintr(Ureg*, Timer *t)
 	case Wakeme:
 		release(p);
 		edfunlock();
-		if(p->trend)
-			wakeup(p->trend);
-		p->trend = nil;
+		twakeup(u, t);
 		if(up){
 			up->delaysched++;
 			delayedscheds++;
@@ -445,8 +443,7 @@ edfstop(Proc *p)
 		if(p->trace && (pt = proctrace))
 			pt(p, SExpel, 0);
 		e->flags &= ~Admitted;
-		if(e->tt)
-			timerdel(e);
+		timerdel(e);
 		edfunlock();
 	}
 }
@@ -479,20 +476,23 @@ edfyield(void)
 	e->r = e->t;
 	e->flags |= Yield;
 	e->d = now;
-	if (up->tt == nil){
-		n = e->t - now;
-		if(n < 20)
-			n = 20;
-		up->tns = 1000LL * n;
-		up->tf = releaseintr;
-		up->tmode = Trelative;
-		up->ta = up;
-		up->trend = &up->sleep;
-		timeradd(up);
-	}else if(up->tf != releaseintr)
-		print("edfyield: surprise! %#p\n", up->tf);
+	n = e->t - now;
+	if(n < 20)
+		n = 20;
+	up->tns = 1000LL * n;
+	up->tf = releaseintr;
+	up->tmode = Trelative;
+	up->ta = up;
+	up->trend = &up->sleep;
+	timeradd(up);
 	edfunlock();
+	if(waserror()){
+		up->trend = nil;
+		timerdel(up);
+		nexterror();
+	}
 	sleep(&up->sleep, yfn, nil);
+	poperror();
 }
 
 int
diff --git a/sys/src/9/port/portclock.c b/sys/src/9/port/portclock.c
index 4b52f6d30..47f85f8e1 100644
--- a/sys/src/9/port/portclock.c
+++ b/sys/src/9/port/portclock.c
@@ -112,9 +112,13 @@ timeradd(Timer *nt)
 void
 timerdel(Timer *dt)
 {
+	Mach *mp;
 	Timers *tt;
 	uvlong when;
 
+	/* avoid Tperiodic getting re-added */
+	dt->tmode = Trelative;
+
 	ilock(dt);
 	if(tt = dt->tt){
 		ilock(tt);
@@ -123,7 +127,16 @@ timerdel(Timer *dt)
 			timerset(tt->head->twhen);
 		iunlock(tt);
 	}
+	if((mp = dt->tactive) == nil || mp->machno == m->machno){
+		iunlock(dt);
+		return;
+	}
 	iunlock(dt);
+
+	/* rare, but tf can still be active on another cpu */
+	while(dt->tactive == mp && dt->tt == nil)
+		if(up->nlocks == 0 && islo())
+			sched();
 }
 
 void
@@ -190,12 +203,14 @@ timerintr(Ureg *u, Tval)
 		tt->head = t->tnext;
 		assert(t->tt == tt);
 		t->tt = nil;
+		t->tactive = MACHP(m->machno);
 		fcallcount[m->machno]++;
 		iunlock(tt);
 		if(t->tf)
 			(*t->tf)(u, t);
 		else
 			callhzclock++;
+		t->tactive = nil;
 		ilock(tt);
 		if(t->tmode == Tperiodic)
 			tadd(tt, t);
diff --git a/sys/src/9/port/portdat.h b/sys/src/9/port/portdat.h
index 00519897e..c91e7a29c 100644
--- a/sys/src/9/port/portdat.h
+++ b/sys/src/9/port/portdat.h
@@ -556,6 +556,7 @@ struct Timer
 	void	*ta;
 	/* Internal */
 	Lock;
+	Mach	*tactive;	/* The cpu that tf is active on */
 	Timers	*tt;		/* Timers queue this timer runs on */
 	Tval	tticks;		/* tns converted to ticks */
 	Tval	twhen;		/* ns represented in fastticks */
diff --git a/sys/src/9/port/portfns.h b/sys/src/9/port/portfns.h
index 5564ce0c8..14ff9ddaa 100644
--- a/sys/src/9/port/portfns.h
+++ b/sys/src/9/port/portfns.h
@@ -348,6 +348,7 @@ void		todinit(void);
 void		todset(vlong, vlong, int);
 Block*		trimblock(Block*, int, int);
 void		tsleep(Rendez*, int (*)(void*), void*, ulong);
+void		twakeup(Ureg*, Timer *);
 int		uartctl(Uart*, char*);
 int		uartgetc(void);
 void		uartkick(void*);
diff --git a/sys/src/9/port/proc.c b/sys/src/9/port/proc.c
index b39fc0942..e9a299c20 100644
--- a/sys/src/9/port/proc.c
+++ b/sys/src/9/port/proc.c
@@ -822,28 +822,17 @@ tfn(void *arg)
 	return up->trend == nil || up->tfn(arg);
 }
 
-static void
+void
 twakeup(Ureg*, Timer *t)
 {
 	Proc *p;
 	Rendez *trend;
 
-	ilock(t);
 	p = t->ta;
 	trend = p->trend;
 	if(trend != nil){
-		wakeup(trend);
 		p->trend = nil;
-	}
-	iunlock(t);
-}
-
-static void
-stoptimer(void)
-{
-	if(up->trend != nil){
-		up->trend = nil;
-		timerdel(up);
+		wakeup(trend);
 	}
 }
 
@@ -864,11 +853,13 @@ tsleep(Rendez *r, int (*fn)(void*), void *arg, ulong ms)
 	timeradd(up);
 
 	if(waserror()){
-		stoptimer();
+		up->trend = nil;
+		timerdel(up);
 		nexterror();
 	}
 	sleep(r, tfn, arg);
-	stoptimer();
+	up->trend = nil;
+	timerdel(up);
 	poperror();
 }
 
@@ -1102,8 +1093,7 @@ pexit(char *exitstr, int freemem)
 	void (*pt)(Proc*, int, vlong);
 
 	up->alarm = 0;
-	if(up->tt != nil)
-		timerdel(up);
+	timerdel(up);
 	pt = proctrace;
 	if(pt != nil)
 		pt(up, SDead, 0);