diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 23ad3fc2442f..51c4c79554f4 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -162,6 +162,11 @@ SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
 extern char *syscallnames[];
 #endif
 
+#ifdef DEVICE_POLLING
+extern u_int32_t poll_in_trap;
+extern int ether_poll __P((int count));
+#endif /* DEVICE_POLLING */
+
 /*
  * Exception, fault, and trap interface to the FreeBSD kernel.
  * This common code is called from assembly language IDT gate entry
@@ -239,6 +244,11 @@ trap(frame)
 			trap_fatal(&frame, eva);
 	}
 
+#ifdef	DEVICE_POLLING
+	if (poll_in_trap)
+		ether_poll(poll_in_trap);
+#endif	/* DEVICE_POLLING */
+
         if ((ISPL(frame.tf_cs) == SEL_UPL) ||
 	    ((frame.tf_eflags & PSL_VM) && !in_vm86call)) {
 		/* user trap */
diff --git a/sys/conf/files.i386 b/sys/conf/files.i386
index 4b827e397bd4..ea9c66644c96 100644
--- a/sys/conf/files.i386
+++ b/sys/conf/files.i386
@@ -383,6 +383,7 @@ isa/syscons_isa.c		optional	sc
 isa/vga_isa.c			optional	vga
 kern/imgact_aout.c		standard
 kern/imgact_gzip.c		optional	gzip
+kern/kern_poll.c		optional	device_polling
 kern/link_aout.c		standard
 kern/md4c.c			optional	netsmb
 kern/subr_diskmbr.c		standard
diff --git a/sys/conf/options.i386 b/sys/conf/options.i386
index 588171a83121..2bb269fbf7c4 100644
--- a/sys/conf/options.i386
+++ b/sys/conf/options.i386
@@ -209,6 +209,11 @@ NETSMBCRYPTO		opt_netsmb.h
 # SMB/CIFS filesystem
 SMBFS
 
+# -------------------------------
+# Polling device handling
+# -------------------------------
+DEVICE_POLLING		opt_global.h
+
 # -------------------------------
 # EOF
 # -------------------------------
diff --git a/sys/dev/dc/if_dc.c b/sys/dev/dc/if_dc.c
index 139983bb089a..caee9d0d44cf 100644
--- a/sys/dev/dc/if_dc.c
+++ b/sys/dev/dc/if_dc.c
@@ -2473,6 +2473,13 @@ static void dc_rxeof(sc)
 
 	while(!(sc->dc_ldata->dc_rx_list[i].dc_status & DC_RXSTAT_OWN)) {
 
+#ifdef DEVICE_POLLING
+		if (ifp->if_ipending & IFF_POLLING) {
+			if (sc->rxcycles <= 0)
+				break;
+			sc->rxcycles--;
+		}
+#endif /* DEVICE_POLLING */
 		cur_rx = &sc->dc_ldata->dc_rx_list[i];
 		rxstat = cur_rx->dc_status;
 		m = sc->dc_cdata.dc_rx_chain[i];
@@ -2786,6 +2793,60 @@ static void dc_tx_underrun(sc)
 	return;
 }
 
+#ifdef DEVICE_POLLING
+static poll_handler_t dc_poll;
+
+static void
+dc_poll(struct ifnet *ifp, enum poll_cmd cmd, int count)
+{
+	struct  dc_softc *sc = ifp->if_softc;
+
+	if (cmd == POLL_DEREGISTER) { /* final call, enable interrupts */
+		/* Re-enable interrupts. */
+		CSR_WRITE_4(sc, DC_IMR, DC_INTRS);
+		return;
+	}
+	sc->rxcycles = count;
+	dc_rxeof(sc);
+	dc_txeof(sc);
+	if (ifp->if_snd.ifq_head != NULL && !(ifp->if_flags & IFF_OACTIVE))
+		dc_start(ifp);
+
+	if (cmd == POLL_AND_CHECK_STATUS) { /* also check status register */
+		u_int32_t	status;
+
+		status = CSR_READ_4(sc, DC_ISR);
+		status &= (DC_ISR_RX_WATDOGTIMEO|DC_ISR_RX_NOBUF|
+			DC_ISR_TX_NOBUF|DC_ISR_TX_IDLE|DC_ISR_TX_UNDERRUN|
+			DC_ISR_BUS_ERR);
+		if (!status)
+			return ;
+		/* ack what we have */
+		CSR_WRITE_4(sc, DC_ISR, status);
+
+		if (status & (DC_ISR_RX_WATDOGTIMEO|DC_ISR_RX_NOBUF) ) {
+			u_int32_t r = CSR_READ_4(sc, DC_FRAMESDISCARDED);
+			ifp->if_ierrors += (r & 0xffff) + ((r >> 17) & 0x7ff);
+
+			if (dc_rx_resync(sc))
+				dc_rxeof(sc);
+		}
+		/* restart transmit unit if necessary */
+		if (status & DC_ISR_TX_IDLE && sc->dc_cdata.dc_tx_cnt)
+			CSR_WRITE_4(sc, DC_TXSTART, 0xFFFFFFFF);
+
+		if (status & DC_ISR_TX_UNDERRUN)
+			dc_tx_underrun(sc);
+
+		if (status & DC_ISR_BUS_ERR) {
+			printf("dc_poll: dc%d bus error\n", sc->dc_unit);
+			dc_reset(sc);
+			dc_init(sc);
+		}
+	}
+}
+#endif /* DEVICE_POLLING */
+
 static void dc_intr(arg)
 	void			*arg;
 {
@@ -2800,6 +2861,14 @@ static void dc_intr(arg)
 
 	DC_LOCK(sc);
 	ifp = &sc->arpcom.ac_if;
+#ifdef DEVICE_POLLING
+	if (ifp->if_ipending & IFF_POLLING)
+		goto done;
+	if (ether_poll_register(dc_poll, ifp)) { /* ok, disable interrupts */
+		CSR_WRITE_4(sc, DC_IMR, 0x00000000);
+		goto done;
+	}
+#endif /* DEVICE_POLLING */
 
 	/* Suppress unwanted interrupts */
 	if (!(ifp->if_flags & IFF_UP)) {
@@ -2864,6 +2933,7 @@ static void dc_intr(arg)
 	if (ifp->if_snd.ifq_head != NULL)
 		dc_start(ifp);
 
+done:
 	DC_UNLOCK(sc);
 
 	return;
@@ -3163,6 +3233,16 @@ static void dc_init(xsc)
 	/*
 	 * Enable interrupts.
 	 */
+#ifdef DEVICE_POLLING
+	/*
+	 * ... but only if we are not polling, and make sure they are off in
+	 * the case of polling. Some cards (e.g. fxp) turn interrupts on
+	 * after a reset.
+	 */
+	if (ifp->if_ipending & IFF_POLLING)
+		CSR_WRITE_4(sc, DC_IMR, 0x00000000);
+	else
+#endif
 	CSR_WRITE_4(sc, DC_IMR, DC_INTRS);
 	CSR_WRITE_4(sc, DC_ISR, 0xFFFFFFFF);
 
@@ -3378,6 +3458,9 @@ static void dc_stop(sc)
 	callout_stop(&sc->dc_stat_ch);
 
 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
+#ifdef DEVICE_POLLING
+	ether_poll_deregister(ifp);
+#endif
 
 	DC_CLRBIT(sc, DC_NETCFG, (DC_NETCFG_RX_ON|DC_NETCFG_TX_ON));
 	CSR_WRITE_4(sc, DC_IMR, 0x00000000);
diff --git a/sys/dev/dc/if_dcreg.h b/sys/dev/dc/if_dcreg.h
index 0052d33d9220..8980e4433d18 100644
--- a/sys/dev/dc/if_dcreg.h
+++ b/sys/dev/dc/if_dcreg.h
@@ -453,7 +453,11 @@ struct dc_desc {
 #define DC_FILTER_HASHONLY	0x10400000
 
 #define DC_MAXFRAGS		16
+#ifdef DEVICE_POLLING
+#define DC_RX_LIST_CNT		192
+#else
 #define DC_RX_LIST_CNT		64
+#endif
 #define DC_TX_LIST_CNT		256
 #define DC_MIN_FRAMELEN		60
 #define DC_RXLEN		1536
@@ -717,6 +721,9 @@ struct dc_softc {
 	int			dc_srm_media;
 #endif
 	struct mtx		dc_mtx;
+#ifdef DEVICE_POLLING
+	int			rxcycles;	/* ... when polling */
+#endif
 };
 
 
diff --git a/sys/dev/fxp/if_fxp.c b/sys/dev/fxp/if_fxp.c
index 840ed8701eb1..27b78432b391 100644
--- a/sys/dev/fxp/if_fxp.c
+++ b/sys/dev/fxp/if_fxp.c
@@ -1141,6 +1141,38 @@ fxp_start(struct ifnet *ifp)
 	}
 }
 
+static void fxp_intr_body(struct fxp_softc *sc, u_int8_t statack, int count);
+
+#ifdef DEVICE_POLLING
+static poll_handler_t fxp_poll;
+
+static void
+fxp_poll(struct ifnet *ifp, enum poll_cmd cmd, int count)  
+{
+	struct fxp_softc *sc = ifp->if_softc;
+	u_int8_t statack ;
+
+	if (cmd == POLL_DEREGISTER) {	/* final call, enable interrupts */
+		CSR_WRITE_1(sc, FXP_CSR_SCB_INTRCNTL, 0);
+		return;
+	}
+	statack = FXP_SCB_STATACK_CXTNO | FXP_SCB_STATACK_CNA |
+		FXP_SCB_STATACK_FR ;
+	if (cmd == POLL_AND_CHECK_STATUS) {
+		u_int8_t tmp ;
+		tmp = CSR_READ_1(sc, FXP_CSR_SCB_STATACK);
+		if (tmp == 0xff || tmp == 0)
+			return ; /* nothing to do */
+		tmp &= ~statack ;
+		/* ack what we can */
+		if (tmp != 0)
+			CSR_WRITE_1(sc, FXP_CSR_SCB_STATACK, tmp);
+		statack |= tmp ;
+	}
+	fxp_intr_body(sc, statack, count);
+}
+#endif /* DEVICE_POLLING */
+
 /*
  * Process interface interrupts.
  */
@@ -1148,9 +1180,21 @@ static void
 fxp_intr(void *xsc)
 {
 	struct fxp_softc *sc = xsc;
-	struct ifnet *ifp = &sc->sc_if;
 	u_int8_t statack;
 
+#ifdef DEVICE_POLLING
+	struct ifnet *ifp = &sc->sc_if;
+
+	if (ifp->if_ipending & IFF_POLLING)
+		return ;
+	if (ether_poll_register(fxp_poll, ifp)) {
+		/* disable interrupts */
+		CSR_WRITE_1(sc, FXP_CSR_SCB_INTRCNTL, FXP_SCB_INTR_DISABLE);
+		fxp_poll(ifp, 0, 1);
+		return ;
+	}
+#endif
+
 	if (sc->suspended) {
 		return;
 	}
@@ -1169,6 +1213,14 @@ fxp_intr(void *xsc)
 		 * First ACK all the interrupts in this pass.
 		 */
 		CSR_WRITE_1(sc, FXP_CSR_SCB_STATACK, statack);
+		fxp_intr_body(sc, statack, -1);
+	}
+}
+
+static void
+fxp_intr_body(struct fxp_softc *sc, u_int8_t statack, int count)
+{
+	struct ifnet *ifp = &sc->sc_if;
 
 		/*
 		 * Free any finished transmit mbuf chains.
@@ -1220,6 +1272,9 @@ fxp_intr(void *xsc)
 			rfa = (struct fxp_rfa *)(m->m_ext.ext_buf +
 			    RFA_ALIGNMENT_FUDGE);
 
+#ifdef DEVICE_POLLING /* loop at most count times if count >=0 */
+			if (count < 0 || count-- > 0)
+#endif
 			if (rfa->rfa_status & FXP_RFA_STATUS_C) {
 				/*
 				 * Remove first packet from the chain.
@@ -1276,7 +1331,6 @@ fxp_intr(void *xsc)
 				fxp_scb_cmd(sc, FXP_SCB_COMMAND_RU_START);
 			}
 		}
-	}
 }
 
 /*
@@ -1404,6 +1458,9 @@ fxp_stop(struct fxp_softc *sc)
 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
 	ifp->if_timer = 0;
 
+#ifdef DEVICE_POLLING
+	ether_poll_deregister(ifp);
+#endif
 	/*
 	 * Cancel stats updater.
 	 */
diff --git a/sys/dev/fxp/if_fxpvar.h b/sys/dev/fxp/if_fxpvar.h
index 23fdaa43ded3..b2ae9b26bfaf 100644
--- a/sys/dev/fxp/if_fxpvar.h
+++ b/sys/dev/fxp/if_fxpvar.h
@@ -57,7 +57,11 @@
  * Number of receive frame area buffers. These are large so chose
  * wisely.
  */
+#ifdef DEVICE_POLLING
+#define FXP_NRFABUFS	192
+#else
 #define FXP_NRFABUFS    64
+#endif
 
 /*
  * Maximum number of seconds that the receiver can be idle before we
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 23ad3fc2442f..51c4c79554f4 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -162,6 +162,11 @@ SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
 extern char *syscallnames[];
 #endif
 
+#ifdef DEVICE_POLLING
+extern u_int32_t poll_in_trap;
+extern int ether_poll __P((int count));
+#endif /* DEVICE_POLLING */
+
 /*
  * Exception, fault, and trap interface to the FreeBSD kernel.
  * This common code is called from assembly language IDT gate entry
@@ -239,6 +244,11 @@ trap(frame)
 			trap_fatal(&frame, eva);
 	}
 
+#ifdef	DEVICE_POLLING
+	if (poll_in_trap)
+		ether_poll(poll_in_trap);
+#endif	/* DEVICE_POLLING */
+
         if ((ISPL(frame.tf_cs) == SEL_UPL) ||
 	    ((frame.tf_eflags & PSL_VM) && !in_vm86call)) {
 		/* user trap */
diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c
index 4c2ccc0a7928..a338dca6a4e6 100644
--- a/sys/kern/kern_clock.c
+++ b/sys/kern/kern_clock.c
@@ -69,6 +69,12 @@
 #include <sys/gmon.h>
 #endif
 
+#ifdef DEVICE_POLLING
+#include <net/netisr.h>		/* for NETISR_POLL */
+ 
+extern void ether_poll1(void);
+extern void hardclock_device_poll(void);
+#endif /* DEVICE_POLLING */
 
 static void initclocks __P((void *dummy));
 SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
@@ -140,6 +146,9 @@ initclocks(dummy)
 	psdiv = pscnt = 1;
 	cpu_initclocks();
 
+#ifdef DEVICE_POLLING
+	register_netisr(NETISR_POLL, ether_poll1);
+#endif
 	/*
 	 * Compute profhz/stathz, and fix profhz if needed.
 	 */
@@ -212,6 +221,9 @@ hardclock(frame)
 		statclock(frame);
 
 	tc_windup();
+#ifdef DEVICE_POLLING
+	hardclock_device_poll();
+#endif /* DEVICE_POLLING */
 
 	/*
 	 * Process callouts at a very low cpu priority, so we don't keep the
diff --git a/sys/kern/kern_intr.c b/sys/kern/kern_intr.c
index e873c6eca819..88868dc5e46e 100644
--- a/sys/kern/kern_intr.c
+++ b/sys/kern/kern_intr.c
@@ -623,7 +623,16 @@ swi_net(void *dummy)
 	u_int bits;
 	int i;
 
+#ifdef DEVICE_POLLING
+    for (;;) {
+	int pollmore;
+#endif
 	bits = atomic_readandclear_int(&netisr);
+#ifdef DEVICE_POLLING
+	if (bits == 0)
+		return;
+	pollmore = bits & (1 << NETISR_POLL);
+#endif
 	while ((i = ffs(bits)) != 0) {
 		i--;
 		if (netisrs[i] != NULL)
@@ -632,6 +641,11 @@ swi_net(void *dummy)
 			printf("swi_net: unregistered isr number: %d.\n", i);
 		bits &= ~(1 << i);
 	}
+#ifdef DEVICE_POLLING
+	if (pollmore)
+		ether_pollmore();
+    }
+#endif
 }
 
 /* 
diff --git a/sys/kern/kern_poll.c b/sys/kern/kern_poll.c
new file mode 100644
index 000000000000..763e5cb25628
--- /dev/null
+++ b/sys/kern/kern_poll.c
@@ -0,0 +1,422 @@
+/*-
+ * Copyright (c) 2001 Luigi Rizzo
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/socket.h>			/* needed by net/if.h		*/
+#include <sys/sysctl.h>
+
+#include <net/if.h>			/* for IFF_* flags		*/
+#include <net/netisr.h>			/* for NETISR_POLL		*/
+
+#ifdef SMP
+#error DEVICE_POLLING is not compatible with SMP
+#endif
+
+void ether_poll1(void);
+void ether_poll(int);			/* polling while in trap	*/
+void ether_pollmore(void);
+void hardclock_device_poll(void);
+
+/*
+ * Polling support for [network] device drivers.
+ *
+ * Drivers which support this feature try to register with the
+ * polling code.
+ *
+ * If registration is successful, the driver must disable interrupts,
+ * and further I/O is performed through the handler, which is invoked
+ * (at least once per clock tick) with 3 arguments: the "arg" passed at
+ * register time (a struct ifnet pointer), a command, and a "count" limit.
+ *
+ * The command can be one of the following:
+ *  POLL_ONLY: quick move of "count" packets from input/output queues.
+ *  POLL_AND_CHECK_STATUS: as above, plus check status registers or do
+ *	other more expensive operations. This command is issued periodically
+ *	but less frequently than POLL_ONLY.
+ *  POLL_DEREGISTER: deregister and return to interrupt mode.
+ *
+ * The first two commands are only issued if the interface is marked as
+ * 'IFF_UP and IFF_RUNNING', the last one only if IFF_RUNNING is set.
+ *
+ * The count limit specifies how much work the handler can do during the
+ * call -- typically this is the number of packets to be received, or
+ * transmitted, etc. (drivers are free to interpret this number, as long
+ * as the max time spent in the function grows roughly linearly with the
+ * count).
+ *
+ * Deregistration can be requested by the driver itself (typically in the
+ * *_stop() routine), or by the polling code, by invoking the handler.
+ *
+ * Polling can be globally enabled or disabled with the sysctl variable
+ * kern.polling.enable (default is 0, disabled)
+ *
+ * A second variable controls the sharing of CPU between polling/kernel
+ * network processing, and other activities (typically userlevel tasks):
+ * kern.polling.user_frac (between 0 and 100, default 50) sets the share
+ * of CPU allocated to user tasks. CPU is allocated proportionally to the
+ * shares, by dynamically adjusting the "count" (poll_burst).
+ *
+ * Other parameters can should be left to their default values.
+ * The following constraints hold
+ *
+ *	1 <= poll_each_burst <= poll_burst <= poll_burst_max
+ *	0 <= poll_in_trap <= poll_each_burst
+ *	MIN_POLL_BURST_MAX <= poll_burst_max <= MAX_POLL_BURST_MAX
+ */
+
+#define MIN_POLL_BURST_MAX	10
+#define MAX_POLL_BURST_MAX	1000
+
+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,
+	&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,
+	&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,
+	&poll_burst_max, 0, "Max Polling burst size");
+
+u_int32_t poll_in_trap;			/* used in trap.c */
+SYSCTL_ULONG(_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,
+	&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,
+	&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,
+	&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,
+	&lost_polls, 0, "How many times we would have lost a poll tick");
+
+static u_int32_t poll_handlers; /* next free entry in pr[]. */
+SYSCTL_ULONG(_kern_polling, OID_AUTO, handlers, CTLFLAG_RD,
+	&poll_handlers, 0, "Number of registered poll handlers");
+
+static int polling = 0;		/* global polling enable */
+SYSCTL_ULONG(_kern_polling, OID_AUTO, enable, CTLFLAG_RW,
+	&polling, 0, "Polling enabled");
+
+
+static u_int32_t poll1_active;
+static u_int32_t need_poll_again;
+
+#define POLL_LIST_LEN  128
+struct pollrec {
+	poll_handler_t	*handler;
+	struct ifnet	*ifp;
+};
+
+static struct pollrec pr[POLL_LIST_LEN];
+
+/*
+ * Hook from hardclock. Tries to schedule a netisr, but keeps track
+ * of lost ticks due to the previous handler taking too long.
+ * The first part of the code is just for debugging purposes, and tries
+ * to count how often hardclock ticks are shorter than they should,
+ * meaning either stray interrupts or delayed events.
+ */
+void
+hardclock_device_poll(void)
+{
+	static struct timeval prev_t, t;
+	int delta;
+
+	microuptime(&t);
+	delta = (t.tv_usec - prev_t.tv_usec) +
+		(t.tv_sec - prev_t.tv_sec)*1000000;
+	if (delta * hz < 500000)
+		short_ticks++;
+	else
+		prev_t = t;
+
+	if (poll_handlers > 0) {
+		if (poll1_active) {
+			lost_polls++;
+			need_poll_again++;
+		} else {
+			poll1_active = 1;
+			schednetisr(NETISR_POLL);
+		}
+	}
+}
+
+/*
+ * ether_poll is called from the idle loop or from the trap handler.
+ */
+void
+ether_poll(int count)
+{
+	int i;
+	int s = splimp();
+
+	mtx_lock(&Giant);
+
+	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(&Giant);
+	splx(s);
+}
+
+/*
+ * ether_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
+ * 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
+ * fastforwarding) and accounting for the work performed in low level
+ * handling and forwarding.
+ */
+
+static int residual_burst = 0;
+
+static struct timeval poll_start_t;
+
+void
+ether_pollmore()
+{
+	struct timeval t;
+	int kern_load;
+	int s = splhigh();
+
+	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 */
+	microuptime(&t);
+	kern_load = (t.tv_usec - poll_start_t.tv_usec) +
+		(t.tv_sec - poll_start_t.tv_sec)*1000000;	/* us */
+	kern_load = (kern_load * hz) / 10000;			/* 0..100 */
+	if (kern_load > (100 - user_frac)) { /* try decrease ticks */
+		if (poll_burst > 1)
+			poll_burst--;
+	} else {
+		if (poll_burst < poll_burst_max)
+			poll_burst++;
+	}
+
+	if (need_poll_again) {
+		/*
+		 * Last cycle was long and caused us to miss one or more
+		 * hardclock ticks. Restart processnig 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);
+}
+
+/*
+ * ether_poll1 is called 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 int reg_frac_count;
+	int i, cycles;
+	enum poll_cmd arg = POLL_ONLY;
+	int s=splimp();
+	mtx_lock(&Giant);
+
+	if (residual_burst == 0) { /* first call in this tick */
+		microuptime(&poll_start_t);
+		/*
+		 * Check that paremeters are consistent with runtime
+		 * variables. Some of these tests could be done at sysctl
+		 * time, but the savings would be very limited because we
+		 * still have to check against reg_frac_count and
+		 * poll_each_burst. So, instead of writing separate sysctl
+		 * handlers, we do all here.
+		 */
+
+		if (reg_frac > hz)
+			reg_frac = hz;
+		else if (reg_frac < 1)
+			reg_frac = 1;
+		if (reg_frac_count > reg_frac)
+			reg_frac_count = reg_frac - 1;
+		if (reg_frac_count-- == 0) {
+			arg = POLL_AND_CHECK_STATUS;
+			reg_frac_count = reg_frac - 1;
+		}
+		if (poll_burst_max < MIN_POLL_BURST_MAX)
+			poll_burst_max = MIN_POLL_BURST_MAX;
+		else if (poll_burst_max > MAX_POLL_BURST_MAX)
+			poll_burst_max = MAX_POLL_BURST_MAX;
+
+		if (poll_each_burst < 1)
+			poll_each_burst = 1;
+		else if (poll_each_burst > poll_burst_max)
+			poll_each_burst = poll_burst_max;
+
+		residual_burst = poll_burst;
+	}
+	cycles = (residual_burst < poll_each_burst) ?
+		residual_burst : poll_each_burst;
+	residual_burst -= cycles;
+
+	if (polling) {
+		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, arg, cycles);
+	} else {	/* unregister */
+		for (i = 0 ; i < poll_handlers ; i++) {
+			if (pr[i].handler &&
+			    pr[i].ifp->if_flags & IFF_RUNNING) {
+				pr[i].ifp->if_ipending &= ~IFF_POLLING;
+				pr[i].handler(pr[i].ifp, POLL_DEREGISTER, 1);
+			}
+			pr[i].handler=NULL;
+		}
+		residual_burst = 0;
+		poll_handlers = 0;
+	}
+	/* on -stable, schednetisr(NETISR_POLLMORE); */
+	mtx_unlock(&Giant);
+	splx(s);
+}
+
+/*
+ * Try to register routine for polling. Returns 1 if successful
+ * (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
+ */
+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	*/
+		return 0;
+	if ( !(ifp->if_flags & IFF_UP) )	/* must be up		*/
+		return 0;
+	if (ifp->if_ipending & IFF_POLLING)	/* already polling	*/
+		return 0;
+
+	s = splhigh();
+	if (poll_handlers >= POLL_LIST_LEN) {
+		/*
+		 * List full, cannot register more entries.
+		 * This should never happen; if it does, it is probably a
+		 * broken driver trying to register multiple times. Checking
+		 * 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 ;
+		splx(s);
+		if (verbose >0) {
+			printf("poll handlers list full, "
+				"maybe a broken driver ?\n");
+			verbose--;
+		}
+		return 0; /* no polling for you */
+	}
+
+	pr[poll_handlers].handler = h;
+	pr[poll_handlers].ifp = ifp;
+	poll_handlers++;
+	ifp->if_ipending |= IFF_POLLING;
+	splx(s);
+	return 1; /* polling enabled in next call */
+}
+
+/*
+ * 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.
+ */
+int
+ether_poll_deregister(struct ifnet *ifp)
+{
+	int i;
+
+	mtx_lock(&Giant);
+	if ( !ifp || !(ifp->if_ipending & IFF_POLLING) ) {
+		mtx_unlock(&Giant);
+		return 0;
+	}
+	for (i = 0 ; i < poll_handlers ; i++)
+		if (pr[i].ifp == ifp) /* found it */
+			break;
+	ifp->if_ipending &= ~IFF_POLLING; /* found or not... */
+	if (i == poll_handlers) {
+		mtx_unlock(&Giant);
+		printf("ether_poll_deregister: ifp not found!!!\n");
+		return 0;
+	}
+	poll_handlers--;
+	if (i < poll_handlers) { /* Last entry replaces this one. */
+		pr[i].handler = pr[poll_handlers].handler;
+		pr[i].ifp = pr[poll_handlers].ifp;
+	}
+	mtx_unlock(&Giant);
+	return 1;
+}
diff --git a/sys/net/if.h b/sys/net/if.h
index 83116b968257..6cc5522118c7 100644
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -131,6 +131,15 @@ struct if_data {
 #define	IFF_ALTPHYS	IFF_LINK2	/* use alternate physical connection */
 #define	IFF_MULTICAST	0x8000		/* supports multicast */
 
+/*
+ * The following flag(s) ought to go in if_flags, but we cannot change
+ * struct ifnet because of binary compatibility, so we store them in
+ * if_ipending, which is not used so far.
+ * If possible, make sure the value is not conflicting with other
+ * IFF flags, so we have an easier time when we want to merge them.
+ */
+#define	IFF_POLLING	0x10000		/* Interface is in polling mode. */
+
 /* flags set internally only: */
 #define	IFF_CANTCHANGE \
 	(IFF_BROADCAST|IFF_POINTOPOINT|IFF_RUNNING|IFF_OACTIVE|\
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index 58d37804620f..dacea6319072 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -459,6 +459,15 @@ int	if_clone_destroy __P((const char *));
 #define IF_LLADDR(ifp)							\
     LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
 
+#ifdef DEVICE_POLLING
+enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };
+
+typedef	void poll_handler_t __P((struct ifnet *ifp,
+		enum poll_cmd cmd, int count));
+int    ether_poll_register __P((poll_handler_t *h, struct ifnet *ifp));
+int    ether_poll_deregister __P((struct ifnet *ifp));
+#endif /* DEVICE_POLLING */
+
 #endif /* _KERNEL */
 
 #endif /* !_NET_IF_VAR_H_ */
diff --git a/sys/net/netisr.h b/sys/net/netisr.h
index 621cf2268b96..35e8cc132252 100644
--- a/sys/net/netisr.h
+++ b/sys/net/netisr.h
@@ -52,6 +52,7 @@
  * interrupt used for scheduling the network code to calls
  * on the lowest level routine of each protocol.
  */
+#define	NETISR_POLL	0		/* polling callback, must be first */
 #define	NETISR_IP	2		/* same as AF_INET */
 #define	NETISR_NS	6		/* same as AF_NS */
 #define	NETISR_ATALK    16              /* same as AF_APPLETALK */
diff --git a/sys/pci/if_dc.c b/sys/pci/if_dc.c
index 139983bb089a..caee9d0d44cf 100644
--- a/sys/pci/if_dc.c
+++ b/sys/pci/if_dc.c
@@ -2473,6 +2473,13 @@ static void dc_rxeof(sc)
 
 	while(!(sc->dc_ldata->dc_rx_list[i].dc_status & DC_RXSTAT_OWN)) {
 
+#ifdef DEVICE_POLLING
+		if (ifp->if_ipending & IFF_POLLING) {
+			if (sc->rxcycles <= 0)
+				break;
+			sc->rxcycles--;
+		}
+#endif /* DEVICE_POLLING */
 		cur_rx = &sc->dc_ldata->dc_rx_list[i];
 		rxstat = cur_rx->dc_status;
 		m = sc->dc_cdata.dc_rx_chain[i];
@@ -2786,6 +2793,60 @@ static void dc_tx_underrun(sc)
 	return;
 }
 
+#ifdef DEVICE_POLLING
+static poll_handler_t dc_poll;
+
+static void
+dc_poll(struct ifnet *ifp, enum poll_cmd cmd, int count)
+{
+	struct  dc_softc *sc = ifp->if_softc;
+
+	if (cmd == POLL_DEREGISTER) { /* final call, enable interrupts */
+		/* Re-enable interrupts. */
+		CSR_WRITE_4(sc, DC_IMR, DC_INTRS);
+		return;
+	}
+	sc->rxcycles = count;
+	dc_rxeof(sc);
+	dc_txeof(sc);
+	if (ifp->if_snd.ifq_head != NULL && !(ifp->if_flags & IFF_OACTIVE))
+		dc_start(ifp);
+
+	if (cmd == POLL_AND_CHECK_STATUS) { /* also check status register */
+		u_int32_t	status;
+
+		status = CSR_READ_4(sc, DC_ISR);
+		status &= (DC_ISR_RX_WATDOGTIMEO|DC_ISR_RX_NOBUF|
+			DC_ISR_TX_NOBUF|DC_ISR_TX_IDLE|DC_ISR_TX_UNDERRUN|
+			DC_ISR_BUS_ERR);
+		if (!status)
+			return ;
+		/* ack what we have */
+		CSR_WRITE_4(sc, DC_ISR, status);
+
+		if (status & (DC_ISR_RX_WATDOGTIMEO|DC_ISR_RX_NOBUF) ) {
+			u_int32_t r = CSR_READ_4(sc, DC_FRAMESDISCARDED);
+			ifp->if_ierrors += (r & 0xffff) + ((r >> 17) & 0x7ff);
+
+			if (dc_rx_resync(sc))
+				dc_rxeof(sc);
+		}
+		/* restart transmit unit if necessary */
+		if (status & DC_ISR_TX_IDLE && sc->dc_cdata.dc_tx_cnt)
+			CSR_WRITE_4(sc, DC_TXSTART, 0xFFFFFFFF);
+
+		if (status & DC_ISR_TX_UNDERRUN)
+			dc_tx_underrun(sc);
+
+		if (status & DC_ISR_BUS_ERR) {
+			printf("dc_poll: dc%d bus error\n", sc->dc_unit);
+			dc_reset(sc);
+			dc_init(sc);
+		}
+	}
+}
+#endif /* DEVICE_POLLING */
+
 static void dc_intr(arg)
 	void			*arg;
 {
@@ -2800,6 +2861,14 @@ static void dc_intr(arg)
 
 	DC_LOCK(sc);
 	ifp = &sc->arpcom.ac_if;
+#ifdef DEVICE_POLLING
+	if (ifp->if_ipending & IFF_POLLING)
+		goto done;
+	if (ether_poll_register(dc_poll, ifp)) { /* ok, disable interrupts */
+		CSR_WRITE_4(sc, DC_IMR, 0x00000000);
+		goto done;
+	}
+#endif /* DEVICE_POLLING */
 
 	/* Suppress unwanted interrupts */
 	if (!(ifp->if_flags & IFF_UP)) {
@@ -2864,6 +2933,7 @@ static void dc_intr(arg)
 	if (ifp->if_snd.ifq_head != NULL)
 		dc_start(ifp);
 
+done:
 	DC_UNLOCK(sc);
 
 	return;
@@ -3163,6 +3233,16 @@ static void dc_init(xsc)
 	/*
 	 * Enable interrupts.
 	 */
+#ifdef DEVICE_POLLING
+	/*
+	 * ... but only if we are not polling, and make sure they are off in
+	 * the case of polling. Some cards (e.g. fxp) turn interrupts on
+	 * after a reset.
+	 */
+	if (ifp->if_ipending & IFF_POLLING)
+		CSR_WRITE_4(sc, DC_IMR, 0x00000000);
+	else
+#endif
 	CSR_WRITE_4(sc, DC_IMR, DC_INTRS);
 	CSR_WRITE_4(sc, DC_ISR, 0xFFFFFFFF);
 
@@ -3378,6 +3458,9 @@ static void dc_stop(sc)
 	callout_stop(&sc->dc_stat_ch);
 
 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
+#ifdef DEVICE_POLLING
+	ether_poll_deregister(ifp);
+#endif
 
 	DC_CLRBIT(sc, DC_NETCFG, (DC_NETCFG_RX_ON|DC_NETCFG_TX_ON));
 	CSR_WRITE_4(sc, DC_IMR, 0x00000000);
diff --git a/sys/pci/if_dcreg.h b/sys/pci/if_dcreg.h
index 0052d33d9220..8980e4433d18 100644
--- a/sys/pci/if_dcreg.h
+++ b/sys/pci/if_dcreg.h
@@ -453,7 +453,11 @@ struct dc_desc {
 #define DC_FILTER_HASHONLY	0x10400000
 
 #define DC_MAXFRAGS		16
+#ifdef DEVICE_POLLING
+#define DC_RX_LIST_CNT		192
+#else
 #define DC_RX_LIST_CNT		64
+#endif
 #define DC_TX_LIST_CNT		256
 #define DC_MIN_FRAMELEN		60
 #define DC_RXLEN		1536
@@ -717,6 +721,9 @@ struct dc_softc {
 	int			dc_srm_media;
 #endif
 	struct mtx		dc_mtx;
+#ifdef DEVICE_POLLING
+	int			rxcycles;	/* ... when polling */
+#endif
 };
 
 
diff --git a/sys/pci/if_sis.c b/sys/pci/if_sis.c
index e74cfa09720e..ec7ee8282304 100644
--- a/sys/pci/if_sis.c
+++ b/sys/pci/if_sis.c
@@ -1273,6 +1273,13 @@ static void sis_rxeof(sc)
 
 	while(SIS_OWNDESC(&sc->sis_ldata.sis_rx_list[i])) {
 
+#ifdef DEVICE_POLLING
+		if (ifp->if_ipending & IFF_POLLING) {
+			if (sc->rxcycles <= 0)
+				break;
+			sc->rxcycles--;
+		}
+#endif /* DEVICE_POLLING */
 		cur_rx = &sc->sis_ldata.sis_rx_list[i];
 		rxstat = cur_rx->sis_rxstat;
 		bus_dmamap_sync(sc->sis_tag,
@@ -1441,6 +1448,55 @@ static void sis_tick(xsc)
 	return;
 }
 
+#ifdef DEVICE_POLLING
+static poll_handler_t sis_poll;
+
+static void
+sis_poll(struct ifnet *ifp, enum poll_cmd cmd, int count)
+{
+	struct  sis_softc *sc = ifp->if_softc;
+	SIS_LOCK(sc);
+	if (cmd == POLL_DEREGISTER) { /* final call, enable interrupts */
+		CSR_WRITE_4(sc, SIS_IER, 1);
+		goto done;
+	}
+
+	/*
+	 * On the sis, reading the status register also clears it.
+	 * So before returning to intr mode we must make sure that all
+	 * possible pending sources of interrupts have been served.
+	 * In practice this means run to completion the *eof routines,
+	 * and then call the interrupt routine
+	 */
+	sc->rxcycles = count;
+	sis_rxeof(sc);
+	sis_txeof(sc);
+	if (ifp->if_snd.ifq_head != NULL)
+		sis_start(ifp);
+
+	if (sc->rxcycles > 0 || cmd == POLL_AND_CHECK_STATUS) {
+		u_int32_t	status;
+
+		/* Reading the ISR register clears all interrupts. */
+		status = CSR_READ_4(sc, SIS_ISR);
+
+		if (status & (SIS_ISR_RX_ERR|SIS_ISR_RX_OFLOW))
+			sis_rxeoc(sc);
+
+		if (status & (SIS_ISR_RX_IDLE))
+			SIS_SETBIT(sc, SIS_CSR, SIS_CSR_RX_ENABLE);
+
+		if (status & SIS_ISR_SYSERR) {
+			sis_reset(sc);
+			sis_init(sc);
+		}
+	}
+done:
+	SIS_UNLOCK(sc);
+	return;
+}
+#endif /* DEVICE_POLLING */
+
 static void sis_intr(arg)
 	void			*arg;
 {
@@ -1452,6 +1508,15 @@ static void sis_intr(arg)
 	ifp = &sc->arpcom.ac_if;
 
 	SIS_LOCK(sc);
+#ifdef DEVICE_POLLING
+	if (ifp->if_ipending & IFF_POLLING)
+		goto done;
+	if (ether_poll_register(sis_poll, ifp)) { /* ok, disable interrupts */
+		CSR_WRITE_4(sc, SIS_IER, 0);
+		goto done;
+	}
+#endif /* DEVICE_POLLING */
+
 	/* Supress unwanted interrupts */
 	if (!(ifp->if_flags & IFF_UP)) {
 		sis_stop(sc);
@@ -1741,6 +1806,15 @@ static void sis_init(xsc)
 	 * Enable interrupts.
 	 */
 	CSR_WRITE_4(sc, SIS_IMR, SIS_INTRS);
+#ifdef DEVICE_POLLING
+	/*
+	 * ... only enable interrupts if we are not polling, make sure
+	 * they are off otherwise.
+	 */
+	if (ifp->if_ipending & IFF_POLLING)
+		CSR_WRITE_4(sc, SIS_IER, 0);
+	else
+#endif /* DEVICE_POLLING */
 	CSR_WRITE_4(sc, SIS_IER, 1);
 
 	/* Enable receiver and transmitter. */
@@ -1910,7 +1984,9 @@ static void sis_stop(sc)
 	untimeout(sis_tick, sc, sc->sis_stat_ch);
 
 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
-
+#ifdef DEVICE_POLLING
+	ether_poll_deregister(ifp);
+#endif
 	CSR_WRITE_4(sc, SIS_IER, 0);
 	CSR_WRITE_4(sc, SIS_IMR, 0);
 	SIS_SETBIT(sc, SIS_CSR, SIS_CSR_TX_DISABLE|SIS_CSR_RX_DISABLE);
diff --git a/sys/pci/if_sisreg.h b/sys/pci/if_sisreg.h
index 7ac424f0d970..803217507e0f 100644
--- a/sys/pci/if_sisreg.h
+++ b/sys/pci/if_sisreg.h
@@ -418,6 +418,9 @@ struct sis_softc {
 	bus_dma_tag_t		sis_tag;
 	struct sis_ring_data	sis_cdata;
 	struct callout_handle	sis_stat_ch;
+#ifdef DEVICE_POLLING
+	int			rxcycles;
+#endif
 	struct mtx		sis_mtx;
 };