From owner-freebsd-bugs@freebsd.org Tue Apr 10 07:29:38 2018 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 3EC5BF841D2 for ; Tue, 10 Apr 2018 07:29:38 +0000 (UTC) (envelope-from brde@optusnet.com.au) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id D0BFD78EB6 for ; Tue, 10 Apr 2018 07:29:37 +0000 (UTC) (envelope-from brde@optusnet.com.au) Received: by mailman.ysv.freebsd.org (Postfix) id 9004AF841CF; Tue, 10 Apr 2018 07:29:37 +0000 (UTC) Delivered-To: bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7DBF8F841CE for ; Tue, 10 Apr 2018 07:29:37 +0000 (UTC) (envelope-from brde@optusnet.com.au) Received: from mail110.syd.optusnet.com.au (mail110.syd.optusnet.com.au [211.29.132.97]) by mx1.freebsd.org (Postfix) with ESMTP id F100E78EB2 for ; Tue, 10 Apr 2018 07:29:36 +0000 (UTC) (envelope-from brde@optusnet.com.au) Received: from [192.168.0.102] (c110-21-101-228.carlnfd1.nsw.optusnet.com.au [110.21.101.228]) by mail110.syd.optusnet.com.au (Postfix) with ESMTPS id A98811013C4 for ; Tue, 10 Apr 2018 17:29:28 +1000 (AEST) Date: Tue, 10 Apr 2018 17:29:28 +1000 (EST) From: Bruce Evans X-X-Sender: bde@besplex.bde.org cc: bugs@freebsd.org Subject: Re: [Bug 227404] UP FreeBSD VM always hangs on reboot since 20180329-r331740 In-Reply-To: Message-ID: <20180410170920.X1375@besplex.bde.org> References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.2 cv=FNpr/6gs c=1 sm=1 tr=0 a=PalzARQSbocsUSjMRkwAPg==:117 a=PalzARQSbocsUSjMRkwAPg==:17 a=9cW_t1CCXrUA:10 a=kj9zAlcOel0A:10 a=JvwiFry8kcIA:10 a=6I5d2MoRAAAA:8 a=yMhMjlubAAAA:8 a=5tWuwmb0sPTj1u1ITqcA:9 a=CjuIK1q_8ugA:10 a=IjZwj45LgO3ly-622nXo:22 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Apr 2018 07:29:38 -0000 On Tue, 10 Apr 2018 a bug that doesn't want replies@freebsd.org wrote: > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=227404 > ... > --- Comment #1 from Dexuan Cui --- > When the issue happens, the cpu utilization of the UP VM is 100%. > > While we're trying to find the first bad revision, it would be great if > somebody can report if the issue also happens to bare metal or other > hypervisors. This has been happening for at least several months on real hardware too. SMP kernels hang on a 1-CPU system and on an 8-CPU systems with all except 1 CPU turned off in the BIOS. They don't hang on the 8-CPU system with at least 2 CPUs turned on. UP kernels don't hang. I use SCHED_4BSD. SCHED_ULE is apparently not much different for this. Bruce