From owner-freebsd-current@FreeBSD.ORG Tue Feb 3 22:17:09 2015 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id F018046C for ; Tue, 3 Feb 2015 22:17:09 +0000 (UTC) Received: from smtp1.ore.mailhop.org (smtp1.ore.mailhop.org [54.68.34.165]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D0ED9800 for ; Tue, 3 Feb 2015 22:17:09 +0000 (UTC) Received: from [73.34.117.227] (helo=ilsoft.org) by smtp1.ore.mailhop.org with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.82) (envelope-from ) id 1YIlO5-0005Ja-Cx; Tue, 03 Feb 2015 21:52:01 +0000 Received: from revolution.hippie.lan (revolution.hippie.lan [172.22.42.240]) by ilsoft.org (8.14.9/8.14.9) with ESMTP id t13LprVa001928; Tue, 3 Feb 2015 14:51:58 -0700 (MST) (envelope-from ian@freebsd.org) X-Mail-Handler: DuoCircle Outbound SMTP X-Originating-IP: 73.34.117.227 X-Report-Abuse-To: abuse@duocircle.com (see https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information for abuse reporting information) X-MHO-User: U2FsdGVkX18gR2940urrfYlZErtqPmwT Message-ID: <1423000313.15718.354.camel@freebsd.org> Subject: Re: PSA: If you run -current, beware! From: Ian Lepore To: Peter Wemm Date: Tue, 03 Feb 2015 14:51:53 -0700 In-Reply-To: <8089702.oYScRm8BTN@overcee.wemm.org> References: <8089702.oYScRm8BTN@overcee.wemm.org> Content-Type: text/plain; charset="us-ascii" X-Mailer: Evolution 3.12.8 FreeBSD GNOME Team Port Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Cc: 'freebsd-current' X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Feb 2015 22:17:10 -0000 On Tue, 2015-02-03 at 13:33 -0800, Peter Wemm wrote: > Sometime in the Dec 10th through Jan 7th timeframe a timing bug has been > introduced to 11.x/head/-current. With HZ=1000 (the default for bare metal, > not for a vm); the clocks stop just after 24 days of uptime. This means > things like cron, sleep, timeouts etc stop working. TCP/IP won't time out or > retransmit, etc etc. It can get ugly. > > The problem is NOT in 10.x/-stable. > > We hit this in the freebsd.org cluster, the builds that we used are: > FreeBSD 11.0-CURRENT #0 r275684: Wed Dec 10 20:38:43 UTC 2014 - fine > FreeBSD 11.0-CURRENT #0 r276779: Wed Jan 7 18:47:09 UTC 2015 - broken > > If you are running -current in a situation where it'll accumulate uptime, you > may want to take precautions. A reboot prior to 24 days uptime (as horrible a > workaround as that is) will avoid it. > > Yes, this is being worked on. FWIW, 24.8 days is the point at which an int32_t variable counting ticks at 1khz rolls over from positive to negative numbers. -- Ian