Remove last callers of the 'lbolt' sleep channel.

When a process in a background group attempts TTY I/O, it is currently
put to sleep on 'lbolt'. This relies on the 1Hz wakeup() from schedcpu().
Replace ttysleep(tp, &lbolt, ...) with ttysleep_nsec(tp, &nowake,
..., SEC_TO_NSEC(1)) and remove unused 'lbolt' channel.

From Tim Leslie, ok claudio.

sys/kern/sched_bsd.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: sched_bsd.c,v 1.104 2025/08/01 10:53:23 claudio Exp $	*/
+/*	$OpenBSD: sched_bsd.c,v 1.105 2025/09/25 08:46:50 mvs Exp $	*/
 /*	$NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $	*/
 
 /*-
@@ -55,7 +55,6 @@
 #endif
 
 uint64_t roundrobin_period;	/* [I] roundrobin period (ns) */
-int	lbolt;			/* once a second sleep address */
 
 struct mutex sched_lock;
 
@@ -282,7 +281,6 @@ schedcpu(void *unused)
 		}
 		SCHED_UNLOCK();
 	}
-	wakeup(&lbolt);
 	timeout_add_sec(&to, 1);
 }
 

sys/kern/tty.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty.c,v 1.181 2025/09/23 08:00:48 mpi Exp $	*/
+/*	$OpenBSD: tty.c,v 1.182 2025/09/25 08:46:50 mvs Exp $	*/
 /*	$NetBSD: tty.c,v 1.68.4.2 1996/06/06 16:04:52 thorpej Exp $	*/
 
 /*-
@@ -79,7 +79,6 @@ void 	filt_ttywdetach(struct knote *kn);
 int	filt_ttyexcept(struct knote *kn, long hint);
 void	ttystats_init(struct itty **, int *, size_t *);
 int	ttywait_nsec(struct tty *, uint64_t);
-int	ttysleep_nsec(struct tty *, void *, int, char *, uint64_t);
 
 /* Symbolic sleep message strings. */
 char ttclos[]	= "ttycls";
@@ -747,8 +746,8 @@ ttioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct proc *p)
 			if (pr->ps_pgrp->pg_jobc == 0)
 				return (EIO);
 			pgsignal(pr->ps_pgrp, SIGTTOU, 1);
-			error = ttysleep(tp, &lbolt, TTOPRI | PCATCH,
-			    ttybg);
+			error = ttysleep_nsec(tp, &nowake, TTOPRI | PCATCH,
+				ttybg, SEC_TO_NSEC(1));
 			if (error)
 				return (error);
 		}
@@ -1515,7 +1514,8 @@ loop:	lflag = tp->t_lflag;
 			goto out;
 		}
 		pgsignal(pr->ps_pgrp, SIGTTIN, 1);
-		error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, ttybg);
+		error = ttysleep_nsec(tp, &nowake, TTIPRI | PCATCH, ttybg, 
+			SEC_TO_NSEC(1));
 		if (error)
 			goto out;
 		goto loop;
@@ -1613,8 +1613,8 @@ read:
 		    ISSET(lflag, IEXTEN | ISIG) == (IEXTEN | ISIG)) {
 			pgsignal(tp->t_pgrp, SIGTSTP, 1);
 			if (first) {
-				error = ttysleep(tp, &lbolt, TTIPRI | PCATCH,
-				    ttybg);
+				error = ttysleep_nsec(tp, &nowake, TTIPRI | PCATCH, 
+					ttybg, SEC_TO_NSEC(1));
 				if (error)
 					break;
 				goto loop;
@@ -1765,7 +1765,8 @@ loop:
 			goto out;
 		}
 		pgsignal(pr->ps_pgrp, SIGTTOU, 1);
-		error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, ttybg);
+		error = ttysleep_nsec(tp, &nowake, TTIPRI | PCATCH, ttybg, 
+			SEC_TO_NSEC(1));
 		if (error)
 			goto out;
 		goto loop;

sys/kern/tty_pty.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty_pty.c,v 1.115 2024/11/05 06:03:19 jsg Exp $	*/
+/*	$OpenBSD: tty_pty.c,v 1.116 2025/09/25 08:46:50 mvs Exp $	*/
 /*	$NetBSD: tty_pty.c,v 1.33.4.1 1996/06/02 09:08:11 mrg Exp $	*/
 
 /*
@@ -294,7 +294,8 @@ again:
 			    pr->ps_flags & PS_PPWAIT)
 				return (EIO);
 			pgsignal(pr->ps_pgrp, SIGTTIN, 1);
-			error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, ttybg);
+			error = ttysleep_nsec(tp, &nowake, TTIPRI | PCATCH, 
+				ttybg, SEC_TO_NSEC(1));
 			if (error)
 				return (error);
 		}

sys/sys/kernel.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: kernel.h,v 1.27 2024/08/14 13:54:08 mvs Exp $	*/
+/*	$OpenBSD: kernel.h,v 1.28 2025/09/25 08:46:50 mvs Exp $	*/
 /*	$NetBSD: kernel.h,v 1.11 1995/03/03 01:24:16 cgd Exp $	*/
 
 /*-
@@ -55,7 +55,6 @@ extern int ticks;		/* # of hardclock ticks */
 extern int hz;			/* system clock's frequency */
 extern int stathz;		/* statistics clock's frequency */
 extern int profhz;		/* profiling clock's frequency */
-extern int lbolt;		/* once a second sleep address */
 
 #ifndef HZ
 #define HZ 100

sys/sys/tty.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty.h,v 1.44 2024/10/26 00:56:35 jsg Exp $	*/
+/*	$OpenBSD: tty.h,v 1.45 2025/09/25 08:46:50 mvs Exp $	*/
 /*	$NetBSD: tty.h,v 1.30.4.1 1996/06/02 09:08:13 mrg Exp $	*/
 
 /*-
@@ -290,6 +290,7 @@ void	 ttypend(struct tty *tp);
 int	 ttyretype(struct tty *tp);
 int	 ttyrub(int c, struct tty *tp);
 int	 ttysleep(struct tty *tp, void *chan, int pri, char *wmesg);
+int	 ttysleep_nsec(struct tty *, void *, int, char *, uint64_t);
 int	 ttywait(struct tty *tp);
 int	 ttywflush(struct tty *tp);
 void	 ttytstamp(struct tty *tp, int octs, int ncts, int odcd, int ndcd);