5 files changed, 39 insertions(+), 16 deletions(-)

M ip/iproute.c
M port/portdat.h
M port/portfns.h
M port/proc.c
M port/sysproc.c

@@ 487,8 487,9 @@ v4lookup(Fs *f, uchar *a, Conv *c)
 	Route *p, *q;
 	ulong la;
 	uchar gate[IPaddrlen];
+	Ipifc *ifc;
 
-	if(c != nil && c->r != nil && c->rgen == v4routegeneration)
+	if(c != nil && c->r != nil && c->r->ifc != nil && c->rgen == v4routegeneration)
 		return c->r;
 
 	la = nhgetl(a);


@@ 509,11 510,13 @@ v4lookup(Fs *f, uchar *a, Conv *c)
 			memmove(gate, v4prefix, IPv4off);
 		} else
 			v4tov6(gate, q->v4.gate);
-		q->ifc = findipifc(f, gate, q->type);
-		if(q->ifc == nil)
+		ifc = findipifc(f, gate, q->type);
+		if(ifc == nil)
 			return nil;
-		q->ifcid = q->ifc->ifcid;
+		q->ifc = ifc;
+		q->ifcid = ifc->ifcid;
 	}
+
 	if(c != nil){
 		c->r = q;
 		c->rgen = v4routegeneration;


@@ 530,6 533,7 @@ v6lookup(Fs *f, uchar *a, Conv *c)
 	int h;
 	ulong x, y;
 	uchar gate[IPaddrlen];
+	Ipifc *ifc;
 
 	if(memcmp(a, v4prefix, IPv4off) == 0){
 		q = v4lookup(f, a+IPv4off, c);


@@ 537,7 541,7 @@ v6lookup(Fs *f, uchar *a, Conv *c)
 			return q;
 	}
 
-	if(c != nil && c->r != nil && c->rgen == v6routegeneration)
+	if(c != nil && c->r != nil && c->r->ifc != nil && c->rgen == v6routegeneration)
 		return c->r;
 
 	for(h = 0; h < IPllen; h++)


@@ 576,12 580,13 @@ next:		;
 		if(q->type & Rifc) {
 			for(h = 0; h < IPllen; h++)
 				hnputl(gate+4*h, q->v6.address[h]);
-			q->ifc = findipifc(f, gate, q->type);
+			ifc = findipifc(f, gate, q->type);
 		} else
-			q->ifc = findipifc(f, q->v6.gate, q->type);
-		if(q->ifc == nil)
+			ifc = findipifc(f, q->v6.gate, q->type);
+		if(ifc == nil)
 			return nil;
-		q->ifcid = q->ifc->ifcid;
+		q->ifc = ifc;
+		q->ifcid = ifc->ifcid;
 	}
 	if(c != nil){
 		c->r = q;

@@ 658,6 658,7 @@ struct Proc
 	ulong	basepri;	/* base priority level */
 	uchar	fixedpri;	/* priority level deson't change */
 	int	quanta;		/* quanta left */
+	uchar	yield;		/* non-zero if the process just did a sleep(0) */
 	ulong	readytime;	/* time process came ready */
 	ulong	movetime;	/* last time process switched processors */
 	int	preempted;	/* true if this process hasn't finished the interrupt

@@ 366,6 366,7 @@ void		xinit(void);
 int		xmerge(void*, void*);
 void*		xspanalloc(ulong, int, ulong);
 void		xsummary(void);
+void		yield(void);
 Segment*	data2txt(Segment*);
 Segment*	dupseg(Segment**, int, int);
 Segment*	newseg(int, ulong, ulong);

@@ 259,6 259,21 @@ ready(Proc *p)
 	splx(s);
 }
 
+/*
+ *  yield the processor to any other runnable process
+ */
+void
+yield(void)
+{
+	if(anyready()){
+		up->yield = 1;
+		sched();
+	}
+}
+
+/*
+ *  pick a process to run
+ */
 Proc*
 runproc(void)
 {


@@ 282,13 297,15 @@ loop:
 	for(i = 0;; i++){
 		/*
 		 *  find the highest priority target process that this
-		 *  processor can run given affinity constraints
+		 *  processor can run given affinity constraints.
+		 *
 		 */
 		for(rq = &runq[Nrq-1]; rq >= runq; rq--){
-			tp = rq->head;
-			if(tp == 0)
-				continue;
-			for(; tp; tp = tp->rnext){
+			for(tp = rq->head; tp; tp = tp->rnext){
+				if(tp->yield){
+					tp->yield = 0;
+					continue;
+				}	
 				if(tp->mp == nil || tp->mp == MACHP(m->machno)
 				|| (!tp->wired && i > 0))
 					goto found;

@@ 540,8 540,7 @@ syssleep(ulong *arg)
 
 	n = arg[0];
 	if(n <= 0) {
-		up->priority = 0;
-		sched();
+		yield();
 		return 0;
 	}
 	if(n < TK2MS(1))