MFcalloutng:

Introduce sbt variants of msleep(), msleep_spin(), pause(), tsleep() in
the KPI, allowing to specify timeout in 'sbintime_t' rather than ticks.

Sponsored by:	Google Summer of Code 2012, iXsystems inc.
Tested by:	flo, marius, ian, markj, Fabian Keil

5 files changed, 54 insertions, 35 deletions

diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index 8783142..5aae8d8 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -146,12 +146,12 @@ sleepinit(void)
  */
 int
 _sleep(void *ident, struct lock_object *lock, int priority,
-    const char *wmesg, int timo)
+    const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags)
 {
 	struct thread *td;
 	struct proc *p;
 	struct lock_class *class;
-	int catch, flags, lock_state, pri, rval;
+	int catch, lock_state, pri, rval, sleepq_flags;
 	WITNESS_SAVE_DECL(lock_witness);
 
 	td = curthread;
@@ -162,7 +162,7 @@ _sleep(void *ident, struct lock_object *lock, int priority,
 #endif
 	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
 	    "Sleeping on \"%s\"", wmesg);
-	KASSERT(timo != 0 || mtx_owned(&Giant) || lock != NULL,
+	KASSERT(sbt != 0 || mtx_owned(&Giant) || lock != NULL,
 	    ("sleeping without a lock"));
 	KASSERT(p != NULL, ("msleep1"));
 	KASSERT(ident != NULL && TD_IS_RUNNING(td), ("msleep"));
@@ -199,13 +199,13 @@ _sleep(void *ident, struct lock_object *lock, int priority,
 		sleepq_remove(td, td->td_wchan);
 
 	if (ident == &pause_wchan)
-		flags = SLEEPQ_PAUSE;
+		sleepq_flags = SLEEPQ_PAUSE;
 	else
-		flags = SLEEPQ_SLEEP;
+		sleepq_flags = SLEEPQ_SLEEP;
 	if (catch)
-		flags |= SLEEPQ_INTERRUPTIBLE;
+		sleepq_flags |= SLEEPQ_INTERRUPTIBLE;
 	if (priority & PBDRY)
-		flags |= SLEEPQ_STOP_ON_BDRY;
+		sleepq_flags |= SLEEPQ_STOP_ON_BDRY;
 
 	sleepq_lock(ident);
 	CTR5(KTR_PROC, "sleep: thread %ld (pid %ld, %s) on %s (%p)",
@@ -231,18 +231,18 @@ _sleep(void *ident, struct lock_object *lock, int priority,
 	 * stopped, then td will no longer be on a sleep queue upon
 	 * return from cursig().
 	 */
-	sleepq_add(ident, lock, wmesg, flags, 0);
-	if (timo)
-		sleepq_set_timeout(ident, timo);
+	sleepq_add(ident, lock, wmesg, sleepq_flags, 0);
+	if (sbt != 0)
+		sleepq_set_timeout_sbt(ident, sbt, pr, flags);
 	if (lock != NULL && class->lc_flags & LC_SLEEPABLE) {
 		sleepq_release(ident);
 		WITNESS_SAVE(lock, lock_witness);
 		lock_state = class->lc_unlock(lock);
 		sleepq_lock(ident);
 	}
-	if (timo && catch)
+	if (sbt != 0 && catch)
 		rval = sleepq_timedwait_sig(ident, pri);
-	else if (timo)
+	else if (sbt != 0)
 		rval = sleepq_timedwait(ident, pri);
 	else if (catch)
 		rval = sleepq_wait_sig(ident, pri);
@@ -263,7 +263,8 @@ _sleep(void *ident, struct lock_object *lock, int priority,
 }
 
 int
-msleep_spin(void *ident, struct mtx *mtx, const char *wmesg, int timo)
+msleep_spin_sbt(void *ident, struct mtx *mtx, const char *wmesg,
+    sbintime_t sbt, sbintime_t pr, int flags)
 {
 	struct thread *td;
 	struct proc *p;
@@ -301,8 +302,8 @@ msleep_spin(void *ident, struct mtx *mtx, const char *wmesg, int timo)
 	 * We put ourselves on the sleep queue and start our timeout.
 	 */
 	sleepq_add(ident, &mtx->lock_object, wmesg, SLEEPQ_SLEEP, 0);
-	if (timo)
-		sleepq_set_timeout(ident, timo);
+	if (sbt != 0)
+		sleepq_set_timeout_sbt(ident, sbt, pr, flags);
 
 	/*
 	 * Can't call ktrace with any spin locks held so it can lock the
@@ -324,7 +325,7 @@ msleep_spin(void *ident, struct mtx *mtx, const char *wmesg, int timo)
 	    wmesg);
 	sleepq_lock(ident);
 #endif
-	if (timo)
+	if (sbt != 0)
 		rval = sleepq_timedwait(ident, 0);
 	else {
 		sleepq_wait(ident, 0);
@@ -348,28 +349,30 @@ msleep_spin(void *ident, struct mtx *mtx, const char *wmesg, int timo)
  * to a "timo" value of one.
  */
 int
-pause(const char *wmesg, int timo)
+pause_sbt(const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags)
 {
-	KASSERT(timo >= 0, ("pause: timo must be >= 0"));
+	int sbt_sec;
+
+	sbt_sec = sbintime_getsec(sbt);
+	KASSERT(sbt_sec >= 0, ("pause: timo must be >= 0"));
 
 	/* silently convert invalid timeouts */
-	if (timo < 1)
-		timo = 1;
+	if (sbt == 0)
+		sbt = tick_sbt;
 
 	if (cold) {
 		/*
-		 * We delay one HZ at a time to avoid overflowing the
+		 * We delay one second at a time to avoid overflowing the
 		 * system specific DELAY() function(s):
 		 */
-		while (timo >= hz) {
+		while (sbt_sec > 0) {
 			DELAY(1000000);
-			timo -= hz;
+			sbt_sec--;
 		}
-		if (timo > 0)
-			DELAY(timo * tick);
+		DELAY((sbt & 0xffffffff) / SBT_1US);
 		return (0);
 	}
-	return (tsleep(&pause_wchan, 0, wmesg, timo));
+	return (_sleep(&pause_wchan, NULL, 0, wmesg, sbt, pr, flags));
 }
 
 /*
diff --git a/sys/sys/mutex.h b/sys/sys/mutex.h
index 9a36b63..85d6996 100644
--- a/sys/sys/mutex.h
+++ b/sys/sys/mutex.h
@@ -376,7 +376,8 @@ extern struct mtx_pool *mtxpool_sleep;
 	mtx_assert_((m), (what), __FILE__, __LINE__)
 
 #define	mtx_sleep(chan, mtx, pri, wmesg, timo)				\
-	_sleep((chan), &(mtx)->lock_object, (pri), (wmesg), (timo))
+	_sleep((chan), &(mtx)->lock_object, (pri), (wmesg),		\
+	    tick_sbt * (timo), 0, C_HARDCLOCK)
 
 #define	mtx_initialized(m)	lock_initalized(&(m)->lock_object)
 
diff --git a/sys/sys/rwlock.h b/sys/sys/rwlock.h
index 8623c05..26e4ac7 100644
--- a/sys/sys/rwlock.h
+++ b/sys/sys/rwlock.h
@@ -211,7 +211,8 @@ void	__rw_assert(const volatile uintptr_t *c, int what, const char *file,
 		rw_runlock(rw);						\
 } while (0)
 #define	rw_sleep(chan, rw, pri, wmesg, timo)				\
-	_sleep((chan), &(rw)->lock_object, (pri), (wmesg), (timo))
+	_sleep((chan), &(rw)->lock_object, (pri), (wmesg),		\
+	    tick_sbt * (timo), 0, C_HARDCLOCK)
 
 #define	rw_initialized(rw)	lock_initalized(&(rw)->lock_object)
 
diff --git a/sys/sys/sx.h b/sys/sys/sx.h
index 8c76a50..01d7112 100644
--- a/sys/sys/sx.h
+++ b/sys/sys/sx.h
@@ -275,7 +275,8 @@ __sx_sunlock(struct sx *sx, const char *file, int line)
 #define	sx_unlock(sx)	sx_unlock_((sx), LOCK_FILE, LOCK_LINE)
 
 #define	sx_sleep(chan, sx, pri, wmesg, timo)				\
-	_sleep((chan), &(sx)->lock_object, (pri), (wmesg), (timo))
+	_sleep((chan), &(sx)->lock_object, (pri), (wmesg),		\
+	    tick_sbt * (timo), 0,  C_HARDCLOCK)
 
 /*
  * Options passed to sx_init_flags().
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index 85fa1c8..f149e6c 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -340,14 +340,27 @@ static __inline void		splx(intrmask_t ipl __unused)	{ return; }
  * less often.
  */
 int	_sleep(void *chan, struct lock_object *lock, int pri, const char *wmesg,
-	    int timo) __nonnull(1);
+	   sbintime_t sbt, sbintime_t pr, int flags) __nonnull(1);
 #define	msleep(chan, mtx, pri, wmesg, timo)				\
-	_sleep((chan), &(mtx)->lock_object, (pri), (wmesg), (timo))
-int	msleep_spin(void *chan, struct mtx *mtx, const char *wmesg, int timo)
-	    __nonnull(1);
-int	pause(const char *wmesg, int timo);
+	_sleep((chan), &(mtx)->lock_object, (pri), (wmesg),		\
+	    tick_sbt * (timo), 0, C_HARDCLOCK)
+#define	msleep_sbt(chan, mtx, pri, wmesg, bt, pr, flags)		\
+	_sleep((chan), &(mtx)->lock_object, (pri), (wmesg), (bt), (pr),	\
+	    (flags))
+int	msleep_spin_sbt(void *chan, struct mtx *mtx, const char *wmesg,
+	    sbintime_t sbt, sbintime_t pr, int flags) __nonnull(1);
+#define	msleep_spin(chan, mtx, wmesg, timo)				\
+	msleep_spin_sbt((chan), (mtx), (wmesg), tick_sbt * (timo),	\
+	    0, C_HARDCLOCK)
+int	pause_sbt(const char *wmesg, sbintime_t sbt, sbintime_t pr,
+	    int flags);
+#define	pause(wmesg, timo)						\
+	pause_sbt((wmesg), tick_sbt * (timo), 0, C_HARDCLOCK)
 #define	tsleep(chan, pri, wmesg, timo)					\
-	_sleep((chan), NULL, (pri), (wmesg), (timo))
+	_sleep((chan), NULL, (pri), (wmesg), tick_sbt * (timo),		\
+	    0, C_HARDCLOCK)
+#define	tsleep_sbt(chan, pri, wmesg, bt, pr, flags)			\
+	_sleep((chan), NULL, (pri), (wmesg), (bt), (pr), (flags))
 void	wakeup(void *chan) __nonnull(1);
 void	wakeup_one(void *chan) __nonnull(1);