From 9493183e7732319b998b8c7b2061883fb9dc4f85 Mon Sep 17 00:00:00 2001
From: Scott Long <scottl@FreeBSD.org>
Date: Thu, 22 Jul 2004 14:32:48 +0000
Subject: [PATCH] Disable the PREEMPTION-enabled code in critical_exit() that
 encourages switching to a different thread.  This is just a hack to try to
 improve stability some more, but likely points closer to the real culprit.

---
 sys/kern/kern_switch.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/kern/kern_switch.c b/sys/kern/kern_switch.c
index 5183a355995b..4822c5edb994 100644
--- a/sys/kern/kern_switch.c
+++ b/sys/kern/kern_switch.c
@@ -450,6 +450,7 @@ critical_exit(void)
 	KASSERT(td->td_critnest != 0,
 	    ("critical_exit: td_critnest == 0"));
 	if (td->td_critnest == 1) {
+#if 0
 #ifdef PREEMPTION
 		mtx_assert(&sched_lock, MA_NOTOWNED);
 		if (td->td_pflags & TDP_OWEPREEMPT) {
@@ -457,6 +458,7 @@ critical_exit(void)
 			mi_switch(SW_INVOL, NULL);
 			mtx_unlock_spin(&sched_lock);
 		}
+#endif
 #endif
 		td->td_critnest = 0;
 		cpu_critical_exit();