From owner-p4-projects@FreeBSD.ORG  Thu Jul  6 18:30:07 2006
Return-Path: <owner-p4-projects@FreeBSD.ORG>
X-Original-To: p4-projects@freebsd.org
Delivered-To: p4-projects@freebsd.org
Received: by hub.freebsd.org (Postfix, from userid 32767)
	id 367BC16A4DF; Thu,  6 Jul 2006 18:30:07 +0000 (UTC)
X-Original-To: perforce@freebsd.org
Delivered-To: perforce@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 139C816A4DA
	for <perforce@freebsd.org>; Thu,  6 Jul 2006 18:30:07 +0000 (UTC)
	(envelope-from jhb@freebsd.org)
Received: from repoman.freebsd.org (repoman.freebsd.org [216.136.204.115])
	by mx1.FreeBSD.org (Postfix) with ESMTP id A882143D53
	for <perforce@freebsd.org>; Thu,  6 Jul 2006 18:30:06 +0000 (GMT)
	(envelope-from jhb@freebsd.org)
Received: from repoman.freebsd.org (localhost [127.0.0.1])
	by repoman.freebsd.org (8.13.6/8.13.6) with ESMTP id k66IU6O6017168
	for <perforce@freebsd.org>; Thu, 6 Jul 2006 18:30:06 GMT
	(envelope-from jhb@freebsd.org)
Received: (from perforce@localhost)
	by repoman.freebsd.org (8.13.6/8.13.4/Submit) id k66IU6ML017165
	for perforce@freebsd.org; Thu, 6 Jul 2006 18:30:06 GMT
	(envelope-from jhb@freebsd.org)
Date: Thu, 6 Jul 2006 18:30:06 GMT
Message-Id: <200607061830.k66IU6ML017165@repoman.freebsd.org>
X-Authentication-Warning: repoman.freebsd.org: perforce set sender to
	jhb@freebsd.org using -f
From: John Baldwin <jhb@FreeBSD.org>
To: Perforce Change Reviews <perforce@freebsd.org>
Cc: 
Subject: PERFORCE change 100784 for review
X-BeenThere: p4-projects@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: p4 projects tree changes <p4-projects.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/p4-projects>,
	<mailto:p4-projects-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/p4-projects>
List-Post: <mailto:p4-projects@freebsd.org>
List-Help: <mailto:p4-projects-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/p4-projects>,
	<mailto:p4-projects-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 06 Jul 2006 18:30:07 -0000

http://perforce.freebsd.org/chv.cgi?CH=100784

Change 100784 by jhb@jhb_mutex on 2006/07/06 18:29:47

	Revert this change.  It ends up tripping a panic because in the
	case of an "extra" thread exiting td_ksegrp will be NULL when we
	do PROC_UNLOCK().  If the proc mtx is contested and this thread
	has a regular user priority for it's base priority, then in
	sched_unlend_prio() when we go to fetch the most recent user
	priority from the ksegroup we panic.

Affected files ...

.. //depot/projects/smpng/sys/kern/kern_thread.c#91 edit

Differences ...

==== //depot/projects/smpng/sys/kern/kern_thread.c#91 (text+ko) ====

@@ -579,6 +579,7 @@
 				ksegrp_unlink(kg);
 				ksegrp_stash(kg);
 			}
+			PROC_UNLOCK(p);
 			td->td_ksegrp	= NULL;
 			PCPU_SET(deadthread, td);
 		} else {
@@ -601,9 +602,9 @@
 		 * This includes an EX threaded process that is coming
 		 * here via exit1(). (exit1 dethreads the proc first).
 		 */
+		PROC_UNLOCK(p);
 	}
 
-	PROC_UNLOCK(p);
 	td->td_state = TDS_INACTIVE;
 	CTR1(KTR_PROC, "thread_exit: cpu_throw() thread %p", td);
 	cpu_throw(td, choosethread());