From owner-svn-src-head@FreeBSD.ORG  Tue Oct 28 03:26:25 2008
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id EE19D1065681;
	Tue, 28 Oct 2008 03:26:25 +0000 (UTC)
	(envelope-from peter@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id DCCB28FC08;
	Tue, 28 Oct 2008 03:26:25 +0000 (UTC)
	(envelope-from peter@FreeBSD.org)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id m9S3QPdh080878;
	Tue, 28 Oct 2008 03:26:25 GMT (envelope-from peter@svn.freebsd.org)
Received: (from peter@localhost)
	by svn.freebsd.org (8.14.3/8.14.3/Submit) id m9S3QPit080877;
	Tue, 28 Oct 2008 03:26:25 GMT (envelope-from peter@svn.freebsd.org)
Message-Id: <200810280326.m9S3QPit080877@svn.freebsd.org>
From: Peter Wemm <peter@FreeBSD.org>
Date: Tue, 28 Oct 2008 03:26:25 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-head@freebsd.org
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r184385 - head/sys/kern
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
	<svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 28 Oct 2008 03:26:26 -0000

Author: peter
Date: Tue Oct 28 03:26:25 2008
New Revision: 184385
URL: http://svn.freebsd.org/changeset/base/184385

Log:
  After a machine has been up for a bit more than 20 days with HZ=1000,
  "ticks" goes negative.  This breaks the signed comparison in softclock.
  This causes sleep() to never wake up, tcp to stop, etc etc.  This is
  bad(TM).  Use the SEQ_LT() method from tcp's sequence number comparisons.

Modified:
  head/sys/kern/kern_timeout.c

Modified: head/sys/kern/kern_timeout.c
==============================================================================
--- head/sys/kern/kern_timeout.c	Tue Oct 28 02:15:17 2008	(r184384)
+++ head/sys/kern/kern_timeout.c	Tue Oct 28 03:26:25 2008	(r184385)
@@ -233,7 +233,7 @@ callout_tick(void)
 	need_softclock = 0;
 	cc = CC_SELF();
 	mtx_lock_spin_flags(&cc->cc_lock, MTX_QUIET);
-	for (; cc->cc_softticks < ticks; cc->cc_softticks++) {
+	for (; (cc->cc_softticks - ticks) < 0; cc->cc_softticks++) {
 		bucket = cc->cc_softticks & callwheelmask;
 		if (!TAILQ_EMPTY(&cc->cc_callwheel[bucket])) {
 			need_softclock = 1;