Index: share/man/man9/tsleep.9
===================================================================
RCS file: /cvs/src/share/man/man9/tsleep.9,v
diff -u -p -r1.16 tsleep.9
--- share/man/man9/tsleep.9	31 Mar 2022 17:27:23 -0000	1.16
+++ share/man/man9/tsleep.9	17 Oct 2024 23:06:37 -0000
@@ -93,11 +93,11 @@
 .Fa "const char *wmesg"
 .Fa "uint64_t nsecs"
 .Fc
-.Ft void
+.Ft int
 .Fn wakeup "void *ident"
-.Ft void
+.Ft int
 .Fn wakeup_n "void *ident" "int count"
-.Ft void
+.Ft int
 .Fn wakeup_one "void *ident"
 .Sh DESCRIPTION
 These functions implement voluntary context switching.
@@ -278,6 +278,12 @@ and
 otherwise.
 If they return as a result of a timeout, the return value is
 .Er EWOULDBLOCK .
+.Pp
+.Fn wakeup ,
+.Fn wakeup n ,
+and
+.Fn wakeup_one
+return the number of processes that were woken up.
 .Sh CODE REFERENCES
 These functions are implemented in the file
 .Pa sys/kern/kern_synch.c .
Index: sys/kern/kern_synch.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_synch.c,v
diff -u -p -r1.206 kern_synch.c
--- sys/kern/kern_synch.c	23 Jul 2024 08:38:02 -0000	1.206
+++ sys/kern/kern_synch.c	17 Oct 2024 23:06:37 -0000
@@ -527,19 +527,18 @@ unsleep(struct proc *p)
 /*
  * Make a number of processes sleeping on the specified identifier runnable.
  */
-void
+int
 wakeup_n(const volatile void *ident, int n)
 {
-	struct slpque *qp, wakeq;
-	struct proc *p;
-	struct proc *pnext;
+	struct slpque wakeq = TAILQ_HEAD_INITIALIZER(wakeq);
+	struct slpque *qp;
+	struct proc *p, *np;
+	int c = 0;
 
-	TAILQ_INIT(&wakeq);
+	qp = &slpque[LOOKUP(ident)];
 
 	SCHED_LOCK();
-	qp = &slpque[LOOKUP(ident)];
-	for (p = TAILQ_FIRST(qp); p != NULL && n != 0; p = pnext) {
-		pnext = TAILQ_NEXT(p, p_runq);
+	TAILQ_FOREACH_SAFE(p, qp, p_runq, np) {
 #ifdef DIAGNOSTIC
 		if (p->p_stat != SSLEEP && p->p_stat != SSTOP)
 			panic("thread %d p_stat is %d", p->p_tid, p->p_stat);
@@ -550,7 +549,9 @@ wakeup_n(const volatile void *ident, int
 			p->p_wchan = NULL;
 			p->p_wmesg = NULL;
 			TAILQ_INSERT_TAIL(&wakeq, p, p_runq);
-			--n;
+
+			if (++c >= n)
+				break;
 		}
 	}
 	while ((p = TAILQ_FIRST(&wakeq))) {
@@ -561,15 +562,17 @@ wakeup_n(const volatile void *ident, int
 			setrunnable(p);
 	}
 	SCHED_UNLOCK();
+
+	return (c);
 }
 
 /*
  * Make all processes sleeping on the specified identifier runnable.
  */
-void
+int
 wakeup(const volatile void *chan)
 {
-	wakeup_n(chan, -1);
+	return wakeup_n(chan, INT_MAX);
 }
 
 int
Index: sys/sys/systm.h
===================================================================
RCS file: /cvs/src/sys/sys/systm.h,v
diff -u -p -r1.171 systm.h
--- sys/sys/systm.h	28 May 2024 12:50:23 -0000	1.171
+++ sys/sys/systm.h	17 Oct 2024 23:06:37 -0000
@@ -269,8 +269,8 @@ void	cond_signal(struct cond *);
 
 struct mutex;
 struct rwlock;
-void    wakeup_n(const volatile void *, int);
-void    wakeup(const volatile void *);
+int     wakeup_n(const volatile void *, int);
+int     wakeup(const volatile void *);
 #define wakeup_one(c) wakeup_n((c), 1)
 int	tsleep(const volatile void *, int, const char *, int);
 int	tsleep_nsec(const volatile void *, int, const char *, uint64_t);