MFS: synchronize the code with the version in -stable, specifically:

+ SYSCTL_ULONG -> SYSCTL_UINT
 + some procedure renaming and variable rearrangement
 + fix the 'interface going deaf' problem same as in -stable.

sys/kern/kern_clock.c

@@ -70,9 +70,7 @@
 #endif
 
 #ifdef DEVICE_POLLING
-#include <net/netisr.h>		/* for NETISR_POLL */
- 
-extern void ether_poll1(void);
+extern void init_device_poll(void);
 extern void hardclock_device_poll(void);
 #endif /* DEVICE_POLLING */
 
@@ -147,7 +145,7 @@ initclocks(dummy)
 	cpu_initclocks();
 
 #ifdef DEVICE_POLLING
-	register_netisr(NETISR_POLL, ether_poll1);
+	init_device_poll();
 #endif
 	/*
 	 * Compute profhz/stathz, and fix profhz if needed.
@@ -222,7 +220,7 @@ hardclock(frame)
 
 	tc_windup();
 #ifdef DEVICE_POLLING
-	hardclock_device_poll();
+	hardclock_device_poll();	/* this is very short and quick */
 #endif /* DEVICE_POLLING */
 
 	/*

sys/kern/kern_intr.c

@@ -644,7 +644,7 @@ swi_net(void *dummy)
 	}
 #ifdef DEVICE_POLLING
 	if (pollmore)
-		ether_pollmore();
+		netisr_pollmore();
     }
 #endif
 }

sys/kern/kern_poll.c

@@ -1,5 +1,7 @@
 /*-
- * Copyright (c) 2001 Luigi Rizzo
+ * Copyright (c) 2001-2002 Luigi Rizzo
+ *
+ * Supported by: the Xorp Project (www.xorp.org)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -42,10 +44,12 @@
 #error DEVICE_POLLING is not compatible with SMP
 #endif
 
-void ether_poll1(void);
+static void netisr_poll(void);		/* the two netisr handlers      */
+void netisr_pollmore(void);
+
+void init_device_poll(void);		/* init routine			*/
+void hardclock_device_poll(void);	/* hook from hardclock		*/
 void ether_poll(int);			/* polling while in trap	*/
-void ether_pollmore(void);
-void hardclock_device_poll(void);
 
 /*
  * Polling support for [network] device drivers.
@@ -101,56 +105,73 @@ SYSCTL_NODE(_kern, OID_AUTO, polling, CTLFLAG_RW, 0,
 	"Device polling parameters");
 
 static u_int32_t poll_burst = 5;
-SYSCTL_ULONG(_kern_polling, OID_AUTO, burst, CTLFLAG_RW,
+SYSCTL_UINT(_kern_polling, OID_AUTO, burst, CTLFLAG_RW,
 	&poll_burst, 0, "Current polling burst size");
 
 static u_int32_t poll_each_burst = 5;
-SYSCTL_ULONG(_kern_polling, OID_AUTO, each_burst, CTLFLAG_RW,
+SYSCTL_UINT(_kern_polling, OID_AUTO, each_burst, CTLFLAG_RW,
 	&poll_each_burst, 0, "Max size of each burst");
 
 static u_int32_t poll_burst_max = 150;	/* good for 100Mbit net and HZ=1000 */
-SYSCTL_ULONG(_kern_polling, OID_AUTO, burst_max, CTLFLAG_RW,
+SYSCTL_UINT(_kern_polling, OID_AUTO, burst_max, CTLFLAG_RW,
 	&poll_burst_max, 0, "Max Polling burst size");
 
+static u_int32_t poll_in_idle_loop=1;	/* do we poll in idle loop ? */
+SYSCTL_UINT(_kern_polling, OID_AUTO, idle_poll, CTLFLAG_RW,
+	&poll_in_idle_loop, 0, "Enable device polling in idle loop");
+
 u_int32_t poll_in_trap;			/* used in trap.c */
-SYSCTL_ULONG(_kern_polling, OID_AUTO, poll_in_trap, CTLFLAG_RW,
+SYSCTL_UINT(_kern_polling, OID_AUTO, poll_in_trap, CTLFLAG_RW,
 	&poll_in_trap, 0, "Poll burst size during a trap");
 
 static u_int32_t user_frac = 50;
-SYSCTL_ULONG(_kern_polling, OID_AUTO, user_frac, CTLFLAG_RW,
+SYSCTL_UINT(_kern_polling, OID_AUTO, user_frac, CTLFLAG_RW,
 	&user_frac, 0, "Desired user fraction of cpu time");
 
 static u_int32_t reg_frac = 20 ;
-SYSCTL_ULONG(_kern_polling, OID_AUTO, reg_frac, CTLFLAG_RW,
+SYSCTL_UINT(_kern_polling, OID_AUTO, reg_frac, CTLFLAG_RW,
 	&reg_frac, 0, "Every this many cycles poll register");
 
 static u_int32_t short_ticks;
-SYSCTL_ULONG(_kern_polling, OID_AUTO, short_ticks, CTLFLAG_RW,
+SYSCTL_UINT(_kern_polling, OID_AUTO, short_ticks, CTLFLAG_RW,
 	&short_ticks, 0, "Hardclock ticks shorter than they should be");
 
 static u_int32_t lost_polls;
-SYSCTL_ULONG(_kern_polling, OID_AUTO, lost_polls, CTLFLAG_RW,
+SYSCTL_UINT(_kern_polling, OID_AUTO, lost_polls, CTLFLAG_RW,
 	&lost_polls, 0, "How many times we would have lost a poll tick");
 
+static u_int32_t pending_polls;
+SYSCTL_UINT(_kern_polling, OID_AUTO, pending_polls, CTLFLAG_RW,
+	&pending_polls, 0, "Do we need to poll again");
+
+static int residual_burst = 0;
+SYSCTL_INT(_kern_polling, OID_AUTO, residual_burst, CTLFLAG_RW,
+	&residual_burst, 0, "# of residual cycles in burst");
+
 static u_int32_t poll_handlers; /* next free entry in pr[]. */
-SYSCTL_ULONG(_kern_polling, OID_AUTO, handlers, CTLFLAG_RD,
+SYSCTL_UINT(_kern_polling, OID_AUTO, handlers, CTLFLAG_RD,
 	&poll_handlers, 0, "Number of registered poll handlers");
 
-static u_int32_t poll_in_idle=1;	/* boolean */
-SYSCTL_ULONG(_kern_polling, OID_AUTO, poll_in_idle, CTLFLAG_RW,
-	&poll_in_idle, 0, "Poll during idle loop");
-
-static u_int32_t idlepoll_sleeping; /* idlepoll is sleeping */
-SYSCTL_ULONG(_kern_polling, OID_AUTO, idlepoll_sleeping, CTLFLAG_RD,
-	&idlepoll_sleeping, 0, "idlepoll is sleeping");
-
 static int polling = 0;		/* global polling enable */
-SYSCTL_ULONG(_kern_polling, OID_AUTO, enable, CTLFLAG_RW,
+SYSCTL_UINT(_kern_polling, OID_AUTO, enable, CTLFLAG_RW,
 	&polling, 0, "Polling enabled");
 
+static volatile u_int32_t phase;
+SYSCTL_UINT(_kern_polling, OID_AUTO, phase, CTLFLAG_RW,
+	&phase, 0, "Polling phase");
+
+static u_int32_t suspect;
+SYSCTL_UINT(_kern_polling, OID_AUTO, suspect, CTLFLAG_RW,
+	&suspect, 0, "suspect event");
+
+static volatile u_int32_t stalled;
+SYSCTL_UINT(_kern_polling, OID_AUTO, stalled, CTLFLAG_RW,
+	&stalled, 0, "potential stalls");
+
+static u_int32_t idlepoll_sleeping; /* idlepoll is sleeping */
+SYSCTL_UINT(_kern_polling, OID_AUTO, idlepoll_sleeping, CTLFLAG_RD,
+	&idlepoll_sleeping, 0, "idlepoll is sleeping");
 
-static u_int32_t poll1_active;
-static u_int32_t need_poll_again;
 
 #define POLL_LIST_LEN  128
 struct pollrec {
@@ -160,6 +181,15 @@ struct pollrec {
 
 static struct pollrec pr[POLL_LIST_LEN];
 
+/*
+ * register relevant netisr. Called from kern_clock.c:
+ */
+void
+init_device_poll(void)
+{
+	register_netisr(NETISR_POLL, netisr_poll);
+}
+
 /*
  * Hook from hardclock. Tries to schedule a netisr, but keeps track
  * of lost ticks due to the previous handler taking too long.
@@ -173,6 +203,9 @@ hardclock_device_poll(void)
 	static struct timeval prev_t, t;
 	int delta;
 
+	if (poll_handlers == 0)
+		return;
+
 	microuptime(&t);
 	delta = (t.tv_usec - prev_t.tv_usec) +
 		(t.tv_sec - prev_t.tv_sec)*1000000;
@@ -181,15 +214,24 @@ hardclock_device_poll(void)
 	else
 		prev_t = t;
 
-	if (poll_handlers > 0) {
-		if (poll1_active) {
-			lost_polls++;
-			need_poll_again++;
-		} else {
-			poll1_active = 1;
-			schednetisr(NETISR_POLL);
-		}
+	if (pending_polls > 100) {
+		/* too much, assume it has stalled */
+		stalled++;
+		printf("poll stalled [%d] in phase %d\n",
+			stalled, phase);
+		pending_polls = 0;
+		phase = 0;
 	}
+
+	if (phase <= 2) {
+		if (phase != 0)
+			suspect++;
+		phase = 1;
+		schednetisr(NETISR_POLL);
+		phase = 2;
+	}
+	if (pending_polls++ > 0)
+		lost_polls++;
 }
 
 /*
@@ -199,7 +241,6 @@ void
 ether_poll(int count)
 {
 	int i;
-	int s = splimp();
 
 	mtx_lock(&Giant);
 
@@ -210,18 +251,17 @@ ether_poll(int count)
 		    (pr[i].ifp->if_flags & (IFF_UP|IFF_RUNNING)) )
 			pr[i].handler(pr[i].ifp, 0, count); /* quick check */
 	mtx_unlock(&Giant);
-	splx(s);
 }
 
 /*
- * ether_pollmore is called after other netisr's, possibly scheduling
+ * netisr_pollmore is called after other netisr's, possibly scheduling
  * another NETISR_POLL call, or adapting the burst size for the next cycle.
  *
  * It is very bad to fetch large bursts of packets from a single card at once,
  * because the burst could take a long time to be completely processed, or
  * could saturate the intermediate queue (ipintrq or similar) leading to
  * losses or unfairness. To reduce the problem, and also to account better for
- * time spent in network-related processnig, we split the burst in smaller
+ * time spent in network-related processing, we split the burst in smaller
  * chunks of fixed size, giving control to the other netisr's between chunks.
  * This helps in improving the fairness, reducing livelock (because we
  * emulate more closely the "process to completion" that we have with
@@ -229,21 +269,19 @@ ether_poll(int count)
  * handling and forwarding.
  */
 
-static int residual_burst = 0;
-
 static struct timeval poll_start_t;
 
 void
-ether_pollmore()
+netisr_pollmore()
 {
 	struct timeval t;
 	int kern_load;
-	int s = splhigh();
+	/* XXX run at splhigh() or equivalent */
 
+	phase = 5;
 	if (residual_burst > 0) {
 		schednetisr(NETISR_POLL);
 		/* will run immediately on return, followed by netisrs */
-		splx(s);
 		return ;
 	}
 	/* here we can account time spent in netisr's in this tick */
@@ -259,36 +297,37 @@ ether_pollmore()
 			poll_burst++;
 	}
 
-	if (need_poll_again) {
+	pending_polls--;
+	if (pending_polls == 0) /* we are done */
+		phase = 0;
+	else {
 		/*
 		 * Last cycle was long and caused us to miss one or more
-		 * hardclock ticks. Restart processnig again, but slightly
+		 * hardclock ticks. Restart processing again, but slightly
 		 * reduce the burst size to prevent that this happens again.
 		 */
-		need_poll_again--;
 		poll_burst -= (poll_burst / 8);
 		if (poll_burst < 1)
 			poll_burst = 1;
 		schednetisr(NETISR_POLL);
-	} else
-		poll1_active = 0;
-	splx(s);
+		phase = 6;
+	}
 }
 
 /*
- * ether_poll1 is called by schednetisr when appropriate, typically once
+ * netisr_poll is scheduled by schednetisr when appropriate, typically once
  * per tick. It is called at splnet() so first thing to do is to upgrade to
  * splimp(), and call all registered handlers.
  */
-void
-ether_poll1(void)
+static void
+netisr_poll(void)
 {
 	static int reg_frac_count;
 	int i, cycles;
 	enum poll_cmd arg = POLL_ONLY;
-	int s=splimp();
 	mtx_lock(&Giant);
 
+	phase = 3;
 	if (residual_burst == 0) { /* first call in this tick */
 		microuptime(&poll_start_t);
 		/*
@@ -344,8 +383,8 @@ ether_poll1(void)
 		poll_handlers = 0;
 	}
 	/* on -stable, schednetisr(NETISR_POLLMORE); */
+	phase = 4;
 	mtx_unlock(&Giant);
-	splx(s);
 }
 
 /*
@@ -353,8 +392,8 @@ ether_poll1(void)
  * (and polling should be enabled), 0 otherwise.
  * A device is not supposed to register itself multiple times.
  *
- * This is called from within the *_intr() function, so we should
- * probably not need further locking. XXX
+ * This is called from within the *_intr() functions, so we do not need
+ * further locking.
  */
 int
 ether_poll_register(poll_handler_t *h, struct ifnet *ifp)
@@ -400,12 +439,10 @@ ether_poll_register(poll_handler_t *h, struct ifnet *ifp)
 }
 
 /*
- * Remove the interface from the list of polling ones.
- * Normally run by *_stop().
- * We allow it being called with IFF_POLLING clear, the
- * call is sufficiently rare so it is preferable to save the
- * space for the extra test in each device in exchange of one
- * additional function call.
+ * Remove interface from the polling list. Normally called by *_stop().
+ * It is not an error to call it with IFF_POLLING clear, the call is
+ * sufficiently rare to be preferable to save the space for the extra
+ * test in each driver in exchange of one additional function call.
  */
 int
 ether_poll_deregister(struct ifnet *ifp)
@@ -450,7 +487,7 @@ poll_idle(void)
 	mtx_unlock_spin(&sched_lock);
 
 	for (;;) {
-		if (poll_in_idle && poll_handlers > 0) {
+		if (poll_in_idle_loop && poll_handlers > 0) {
 			idlepoll_sleeping = 0;
 			mtx_lock(&Giant);
 			ether_poll(poll_each_burst);