Index: compat/ndis/kern_ndis.c
===================================================================
RCS file: /usr/cvs/src/sys/compat/ndis/kern_ndis.c,v
retrieving revision 1.93
diff -u -r1.93 kern_ndis.c
--- compat/ndis/kern_ndis.c	23 Feb 2007 12:18:28 -0000	1.93
+++ compat/ndis/kern_ndis.c	23 Feb 2007 15:59:19 -0000
@@ -1248,7 +1248,7 @@
 	 * expects them to fire before the halt is called.
 	 */
 
-	tsleep(curthread->td_proc, PWAIT, "ndwait", hz);
+	pause("ndwait", hz);
 
 	NDIS_LOCK(sc);
 	sc->ndis_block->nmb_devicectx = sc;
Index: dev/acpica/Osd/OsdSchedule.c
===================================================================
RCS file: /usr/cvs/src/sys/dev/acpica/Osd/OsdSchedule.c,v
retrieving revision 1.37
diff -u -r1.37 OsdSchedule.c
--- dev/acpica/Osd/OsdSchedule.c	16 May 2006 14:36:22 -0000	1.37
+++ dev/acpica/Osd/OsdSchedule.c	23 Feb 2007 15:59:19 -0000
@@ -132,7 +132,6 @@
 AcpiOsSleep(ACPI_INTEGER Milliseconds)
 {
     int		timo;
-    static int	dummy;
 
     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
 
@@ -143,7 +142,7 @@
      * DELAY instead for better granularity.
      */
     if (timo > 0)
-	tsleep(&dummy, 0, "acpislp", timo);
+	pause("acpislp", timo);
     else
 	DELAY(Milliseconds * 1000);
 
Index: dev/ata/ata-all.c
===================================================================
RCS file: /usr/cvs/src/sys/dev/ata/ata-all.c,v
retrieving revision 1.278
diff -u -r1.278 ata-all.c
--- dev/ata/ata-all.c	23 Feb 2007 12:18:32 -0000	1.278
+++ dev/ata/ata-all.c	23 Feb 2007 15:59:19 -0000
@@ -122,7 +122,7 @@
 
     /* reset the controller HW, the channel and device(s) */
     while (ATA_LOCKING(dev, ATA_LF_LOCK) != ch->unit)
-	tsleep(&error, PRIBIO, "ataatch", 1);
+	pause("ataatch", 1);
     ATA_RESET(dev);
     ATA_LOCKING(dev, ATA_LF_UNLOCK);
 
@@ -196,7 +196,7 @@
 
     /* poll for locking the channel */
     while (ATA_LOCKING(dev, ATA_LF_LOCK) != ch->unit)
-	tsleep(&dev, PRIBIO, "atarini", 1);
+	pause("atarini", 1);
 
     /* catch eventual request in ch->running */
     mtx_lock(&ch->state_mtx);
@@ -824,7 +824,7 @@
     if (1 || interval < (1000000/hz) || ata_delayed_attach)
 	DELAY(interval);
     else
-	tsleep(&interval, PRIBIO, "ataslp", interval/(1000000/hz));
+	pause("ataslp", interval/(1000000/hz));
 }
 
 char *
Index: dev/ata/atapi-cd.c
===================================================================
RCS file: /usr/cvs/src/sys/dev/ata/atapi-cd.c,v
retrieving revision 1.192
diff -u -r1.192 atapi-cd.c
--- dev/ata/atapi-cd.c	21 Feb 2007 19:07:18 -0000	1.192
+++ dev/ata/atapi-cd.c	23 Feb 2007 15:59:19 -0000
@@ -710,7 +710,7 @@
 	     request->u.atapi.sense.key == 7) &&
 	    request->u.atapi.sense.asc == 4 &&
 	    request->u.atapi.sense.ascq == 1)
-	    tsleep(&timeout, PRIBIO, "acdld", hz / 2);
+	    pause("acdld", hz / 2);
 	else
 	    break;
     }
@@ -1095,7 +1095,7 @@
     /* some drives just return ready, wait for the expected fixate time */
     if ((error = acd_test_ready(dev)) != EBUSY) {
 	timeout = timeout / (cdp->cap.cur_write_speed / 177);
-	tsleep(&error, PRIBIO, "acdfix", timeout * hz / 2);
+	pause("acdfix", timeout * hz / 2);
 	return acd_test_ready(dev);
     }
 
@@ -1104,7 +1104,7 @@
 	    return error;
 	if ((error = acd_test_ready(dev)) != EBUSY)
 	    return error;
-	tsleep(&error, PRIBIO, "acdcld", hz / 2);
+	pause("acdcld", hz / 2);
     }
     return EIO;
 }
Index: dev/ata/atapi-tape.c
===================================================================
RCS file: /usr/cvs/src/sys/dev/ata/atapi-tape.c,v
retrieving revision 1.102
diff -u -r1.102 atapi-tape.c
--- dev/ata/atapi-tape.c	21 Feb 2007 19:07:19 -0000	1.102
+++ dev/ata/atapi-tape.c	23 Feb 2007 15:59:19 -0000
@@ -612,7 +612,7 @@
     error = ata_atapicmd(dev, ccb, NULL, 0, 0, 10);
     if (error)
 	return error;
-    tsleep((caddr_t)&error, PRIBIO, "astlu", 1 * hz);
+    pause("astlu", 1 * hz);
     if (function == ATAPI_SS_EJECT)
 	return 0;
     return ast_wait_dsc(dev, 60*60);
@@ -665,7 +665,7 @@
 	error = ata_atapicmd(dev, ccb, NULL, 0, 0, 0);
 	if (error != EBUSY)
 	    break;
-	tsleep(&error, PRIBIO, "atpwt", hz / 2);
+	pause("atpwt", hz / 2);
 	timeout -= (hz / 2);
     }
     return error;
Index: dev/ppc/ppc.c
===================================================================
RCS file: /usr/cvs/src/sys/dev/ppc/ppc.c,v
retrieving revision 1.53
diff -u -r1.53 ppc.c
--- dev/ppc/ppc.c	23 Feb 2007 12:18:50 -0000	1.53
+++ dev/ppc/ppc.c	23 Feb 2007 15:59:19 -0000
@@ -1393,8 +1393,7 @@
 
 		case MS_OP_ADELAY:
 			if (mi->arg[0].i)
-				tsleep(NULL, PPBPRI, "ppbdelay",
-						mi->arg[0].i * (hz/1000));
+				pause("ppbdelay", mi->arg[0].i * (hz/1000));
 			INCR_PC;
 			break;
 
Index: kern/kern_synch.c
===================================================================
RCS file: /usr/cvs/src/sys/kern/kern_synch.c,v
retrieving revision 1.287
diff -u -r1.287 kern_synch.c
--- kern/kern_synch.c	3 Jan 2007 02:38:41 -0000	1.287
+++ kern/kern_synch.c	23 Feb 2007 15:59:19 -0000
@@ -69,6 +69,7 @@
 
 int	hogticks;
 int	lbolt;
+static int pause_wchan;
 
 static struct callout loadav_callout;
 static struct callout lbolt_callout;
@@ -164,7 +165,10 @@
 	if (TD_ON_SLEEPQ(td))
 		sleepq_remove(td, td->td_wchan);
 
-	flags = SLEEPQ_MSLEEP;
+	if (ident == &pause_wchan)
+		flags = SLEEPQ_PAUSE;
+	else
+		flags = SLEEPQ_MSLEEP;
 	if (catch)
 		flags |= SLEEPQ_INTERRUPTIBLE;
 
@@ -308,6 +312,22 @@
 }
 
 /*
+ * pause() is like tsleep() except that the intention is to not be
+ * explicitly woken up by another thread.  Instead, the current thread
+ * simply wishes to sleep until the timeout expires.  It is
+ * implemented using a dummy wait channel.
+ */
+int
+pause(wmesg, timo)
+	const char *wmesg;
+	int timo;
+{
+
+	KASSERT(timo != 0, ("pause: timeout required"));
+	return (tsleep(&pause_wchan, 0, wmesg, timo));
+}
+
+/*
  * Make all threads sleeping on the specified identifier runnable.
  */
 void
Index: sys/sleepqueue.h
===================================================================
RCS file: /usr/cvs/src/sys/sys/sleepqueue.h,v
retrieving revision 1.9
diff -u -r1.9 sleepqueue.h
--- sys/sleepqueue.h	16 Dec 2006 06:54:09 -0000	1.9
+++ sys/sleepqueue.h	23 Feb 2007 15:59:19 -0000
@@ -84,6 +84,7 @@
 #define	SLEEPQ_TYPE		0x0ff		/* Mask of sleep queue types. */
 #define	SLEEPQ_MSLEEP		0x00		/* Used by msleep/wakeup. */
 #define	SLEEPQ_CONDVAR		0x01		/* Used for a cv. */
+#define	SLEEPQ_PAUSE		0x02		/* Used by pause. */
 #define	SLEEPQ_INTERRUPTIBLE	0x100		/* Sleep is interruptible. */
 
 void	init_sleepqueues(void);
Index: sys/systm.h
===================================================================
RCS file: /usr/cvs/src/sys/sys/systm.h,v
retrieving revision 1.249
diff -u -r1.249 systm.h
--- sys/systm.h	14 Feb 2007 05:21:22 -0000	1.249
+++ sys/systm.h	23 Feb 2007 15:59:19 -0000
@@ -310,6 +310,7 @@
 int	msleep(void *chan, struct mtx *mtx, int pri, const char *wmesg,
 	    int timo);
 int	msleep_spin(void *chan, struct mtx *mtx, const char *wmesg, int timo);
+int	pause(const char *wmesg, int timo);
 #define	tsleep(chan, pri, wmesg, timo)	msleep(chan, NULL, pri, wmesg, timo)
 void	wakeup(void *chan) __nonnull(1);
 void	wakeup_one(void *chan) __nonnull(1);