From owner-p4-projects@FreeBSD.ORG  Sun Jan 14 18:55:42 2007
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 6C67216A4A7; Sun, 14 Jan 2007 18:55:42 +0000 (UTC)
X-Original-To: perforce@FreeBSD.org
Delivered-To: perforce@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 2995916A492
	for <perforce@FreeBSD.org>; Sun, 14 Jan 2007 18:55:42 +0000 (UTC)
	(envelope-from zec@FreeBSD.org)
Received: from repoman.freebsd.org (repoman.freebsd.org [69.147.83.41])
	by mx1.freebsd.org (Postfix) with ESMTP id 1A7BE13C43E
	for <perforce@FreeBSD.org>; Sun, 14 Jan 2007 18:55:42 +0000 (UTC)
	(envelope-from zec@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 l0EItf3a055793
	for <perforce@FreeBSD.org>; Sun, 14 Jan 2007 18:55:41 GMT
	(envelope-from zec@FreeBSD.org)
Received: (from perforce@localhost)
	by repoman.freebsd.org (8.13.6/8.13.4/Submit) id l0EIteT0055776
	for perforce@freebsd.org; Sun, 14 Jan 2007 18:55:40 GMT
	(envelope-from zec@FreeBSD.org)
Date: Sun, 14 Jan 2007 18:55:40 GMT
Message-Id: <200701141855.l0EIteT0055776@repoman.freebsd.org>
X-Authentication-Warning: repoman.freebsd.org: perforce set sender to
	zec@FreeBSD.org using -f
From: Marko Zec <zec@FreeBSD.org>
To: Perforce Change Reviews <perforce@FreeBSD.org>
Cc: 
Subject: PERFORCE change 112910 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: Sun, 14 Jan 2007 18:55:42 -0000

http://perforce.freebsd.org/chv.cgi?CH=112910

Change 112910 by zec@zec_tca51 on 2007/01/14 18:54:54

	In callout_reset() check whether the handle provided by the
	caller is already linked in somewhere in the callout wheel.  If
	it is, panic.
	
	This check can be insanely expensive and shouldn't be compiled
	in under normal circumstances, but at the moment I need this
	for chasing ghosts...

Affected files ...

.. //depot/projects/vimage/src/sys/kern/kern_timeout.c#2 edit

Differences ...

==== //depot/projects/vimage/src/sys/kern/kern_timeout.c#2 (text+ko) ====

@@ -37,6 +37,8 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD: src/sys/kern/kern_timeout.c,v 1.102 2006/10/11 14:57:03 glebius Exp $");
 
+#include "opt_vimage.h"
+
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/callout.h>
@@ -465,6 +467,23 @@
 	c->c_flags |= (CALLOUT_ACTIVE | CALLOUT_PENDING);
 	c->c_func = ftn;
 	c->c_time = ticks + to_ticks;
+#if (defined(VIMAGE) && defined(INVARIANTS))
+	/*
+	 * MARKO XXX
+	 *
+	 * I'm suspecting that some lockups might have been caused by
+	 * a single callout handle being scheduled multiple times.
+	 * This loop examines the entire callwhell before inserting a
+	 * new handle, and if the handle is already linked in it panics.
+	 */
+	int callwheel_iter;
+	struct callout *c_iter;
+	for (callwheel_iter = 0; callwheel_iter <= callwheelmask;
+	    callwheel_iter++)
+		TAILQ_FOREACH(c_iter, &callwheel[callwheel_iter], c_links.tqe)
+			if (c_iter == c)
+				panic("finally got you!");
+#endif
 	TAILQ_INSERT_TAIL(&callwheel[c->c_time & callwheelmask], 
 			  c, c_links.tqe);
 	CTR5(KTR_CALLOUT, "%sscheduled %p func %p arg %p in %d",