PERFORCE change 39477 for review

[Sam Leffler]

http://perforce.freebsd.org/chv.cgi?CH=39477

Change 39477 by sam at sam_ebb on 2003/10/10 16:27:19

	revert locking changes

Affected files ...

.. //depot/projects/netperf/sys/kern/kern_poll.c#3 edit

Differences ...

==== //depot/projects/netperf/sys/kern/kern_poll.c#3 (text+ko) ====

@@ -182,13 +182,11 @@
 };
 
 static struct pollrec pr[POLL_LIST_LEN];
-static struct mtx poll_mtx;
 
 static void
 init_device_poll(void)
 {
 
-	mtx_init(&poll_mtx, "device polling", NULL, MTX_DEF);
 	netisr_register(NETISR_POLL, (netisr_t *)netisr_poll, NULL);
 	netisr_register(NETISR_POLLMORE, (netisr_t *)netisr_pollmore, NULL);
 }
@@ -225,7 +223,6 @@
 	else
 		prev_t = t;
 
-	mtx_lock(&poll_mtx);
 	if (pending_polls > 100) {
 		/*
 		 * Too much, assume it has stalled (not always true
@@ -245,7 +242,6 @@
 	}
 	if (pending_polls++ > 0)
 		lost_polls++;
-	mtx_unlock(&poll_mtx);
 }
 
 /*
@@ -256,16 +252,15 @@
 {
 	int i;
 
-	mtx_assert(&Giant, MA_NOTOWNED);
+	mtx_lock(&Giant);
 
-	mtx_lock(&poll_mtx);
 	if (count > poll_each_burst)
 		count = poll_each_burst;
 	for (i = 0 ; i < poll_handlers ; i++)
 		if (pr[i].handler && (IFF_UP|IFF_RUNNING) ==
 		    (pr[i].ifp->if_flags & (IFF_UP|IFF_RUNNING)) )
 			pr[i].handler(pr[i].ifp, 0, count); /* quick check */
-	mtx_unlock(&poll_mtx);
+	mtx_unlock(&Giant);
 }
 
 /*
@@ -293,14 +288,10 @@
 	int kern_load;
 	/* XXX run at splhigh() or equivalent */
 
-	mtx_assert(&Giant, MA_NOTOWNED);
-
-	mtx_lock(&poll_mtx);
 	phase = 5;
 	if (residual_burst > 0) {
 		schednetisrbits(1 << NETISR_POLL | 1 << NETISR_POLLMORE);
 		/* will run immediately on return, followed by netisrs */
-		mtx_unlock(&poll_mtx);
 		return;
 	}
 	/* here we can account time spent in netisr's in this tick */
@@ -331,12 +322,12 @@
 		schednetisrbits(1 << NETISR_POLL | 1 << NETISR_POLLMORE);
 		phase = 6;
 	}
-	mtx_unlock(&poll_mtx);
 }
 
 /*
  * netisr_poll is scheduled by schednetisr when appropriate, typically once
- * per tick.
+ * per tick. It is called at splnet() so first thing to do is to upgrade to
+ * splimp(), and call all registered handlers.
  */
 static void
 netisr_poll(void)
@@ -344,10 +335,8 @@
 	static int reg_frac_count;
 	int i, cycles;
 	enum poll_cmd arg = POLL_ONLY;
+	mtx_lock(&Giant);
 
-	mtx_assert(&Giant, MA_NOTOWNED);
-
-	mtx_lock(&poll_mtx);
 	phase = 3;
 	if (residual_burst == 0) { /* first call in this tick */
 		microuptime(&poll_start_t);
@@ -405,7 +394,7 @@
 	}
 	/* on -stable, schednetisr(NETISR_POLLMORE); */
 	phase = 4;
-	mtx_lock(&poll_mtx);
+	mtx_unlock(&Giant);
 }
 
 /*
@@ -419,6 +408,8 @@
 int
 ether_poll_register(poll_handler_t *h, struct ifnet *ifp)
 {
+	int s;
+
 	if (polling == 0) /* polling disabled, cannot register */
 		return 0;
 	if (h == NULL || ifp == NULL)		/* bad arguments	*/
@@ -428,7 +419,7 @@
 	if (ifp->if_flags & IFF_POLLING)	/* already polling	*/
 		return 0;
 
-	mtx_lock(&poll_mtx);
+	s = splhigh();
 	if (poll_handlers >= POLL_LIST_LEN) {
 		/*
 		 * List full, cannot register more entries.
@@ -437,8 +428,8 @@
 		 * this at runtime is expensive, and won't solve the problem
 		 * anyways, so just report a few times and then give up.
 		 */
-		static int verbose = 10;
-		mtx_unlock(&poll_mtx);
+		static int verbose = 10 ;
+		splx(s);
 		if (verbose >0) {
 			printf("poll handlers list full, "
 				"maybe a broken driver ?\n");
@@ -451,7 +442,7 @@
 	pr[poll_handlers].ifp = ifp;
 	poll_handlers++;
 	ifp->if_flags |= IFF_POLLING;
-	mtx_unlock(&poll_mtx);
+	splx(s);
 	if (idlepoll_sleeping)
 		wakeup(&idlepoll_sleeping);
 	return 1; /* polling enabled in next call */
@@ -468,9 +459,9 @@
 {
 	int i;
 
-	mtx_lock(&poll_mtx);
+	mtx_lock(&Giant);
 	if ( !ifp || !(ifp->if_flags & IFF_POLLING) ) {
-		mtx_unlock(&poll_mtx);
+		mtx_unlock(&Giant);
 		return 0;
 	}
 	for (i = 0 ; i < poll_handlers ; i++)
@@ -478,8 +469,8 @@
 			break;
 	ifp->if_flags &= ~IFF_POLLING; /* found or not... */
 	if (i == poll_handlers) {
-		mtx_unlock(&poll_mtx);
-		printf("%s: ifp not found!!!\n", __func__);
+		mtx_unlock(&Giant);
+		printf("ether_poll_deregister: ifp not found!!!\n");
 		return 0;
 	}
 	poll_handlers--;
@@ -487,7 +478,7 @@
 		pr[i].handler = pr[poll_handlers].handler;
 		pr[i].ifp = pr[poll_handlers].ifp;
 	}
-	mtx_unlock(&poll_mtx);
+	mtx_unlock(&Giant);
 	return 1;
 }
 
@@ -508,7 +499,10 @@
 	for (;;) {
 		if (poll_in_idle_loop && poll_handlers > 0) {
 			idlepoll_sleeping = 0;
+			mtx_lock(&Giant);
 			ether_poll(poll_each_burst);
+			mtx_unlock(&Giant);
+			mtx_assert(&Giant, MA_NOTOWNED);
 			mtx_lock_spin(&sched_lock);
 			td->td_proc->p_stats->p_ru.ru_nvcsw++;
 			mi_switch();