From 6942d4339e3060ab833571c46b72f1ff9c14f82e Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Tue, 13 Jul 2004 20:49:13 +0000
Subject: [PATCH] Set TDF_NEEDRESCHED when a higher priority thread is
 scheduled in sched_add() rather than just doing it in sched_wakeup().  The
 old ithread preemption code used to set NEEDRESCHED unconditionally if it
 didn't preempt which masked this bug in SCHED_4BSD.

Noticed by:	jake
Reported by:	kensmith, marcel
---
 sys/kern/sched_4bsd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/kern/sched_4bsd.c b/sys/kern/sched_4bsd.c
index b2ae3dd123a5..2a51bc04d864 100644
--- a/sys/kern/sched_4bsd.c
+++ b/sys/kern/sched_4bsd.c
@@ -694,7 +694,6 @@ sched_wakeup(struct thread *td)
 		updatepri(kg);
 	kg->kg_slptime = 0;
 	setrunqueue(td);
-	maybe_resched(td);
 }
 
 void
@@ -740,6 +739,7 @@ sched_add(struct thread *td)
 	if ((td->td_proc->p_flag & P_NOLOAD) == 0)
 		sched_tdcnt++;
 	runq_add(ke->ke_runq, ke);
+	maybe_resched(td);
 }
 
 void