From owner-freebsd-current@FreeBSD.ORG Sun Nov 16 18:32:01 2014 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 11A26DF7; Sun, 16 Nov 2014 18:32:01 +0000 (UTC) Received: from mho-02-ewr.mailhop.org (mho-02-ewr.mailhop.org [204.13.248.72]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id CEAE588B; Sun, 16 Nov 2014 18:32:00 +0000 (UTC) Received: from [73.34.117.227] (helo=ilsoft.org) by mho-02-ewr.mailhop.org with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.72) (envelope-from ) id 1Xq4cB-0004WD-Cn; Sun, 16 Nov 2014 18:31:59 +0000 Received: from [172.22.42.240] (revolution.hippie.lan [172.22.42.240]) by ilsoft.org (8.14.9/8.14.9) with ESMTP id sAGIVwhN001401; Sun, 16 Nov 2014 11:31:58 -0700 (MST) (envelope-from ian@FreeBSD.org) X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 73.34.117.227 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX1+9ndMg+1VaK20PX+H91Qch X-Authentication-Warning: paranoia.hippie.lan: Host revolution.hippie.lan [172.22.42.240] claimed to be [172.22.42.240] Subject: Re: USB locks up system -- WAS Re: shutdown or acpi problem From: Ian Lepore To: Mark R V Murray In-Reply-To: References: <20141112224212.GA14013@troutmask.apl.washington.edu> <20141113172533.GA18690@troutmask.apl.washington.edu> <20141113180332.GA18990@troutmask.apl.washington.edu> <20141113181515.GA19117@troutmask.apl.washington.edu> <546515BF.6030508@selasky.org> <20141113212206.GA20802@troutmask.apl.washington.edu> <20141116054141.GA33186@troutmask.apl.washington.edu> <20141116175102.GA35649@troutmask.apl.washington.edu> <1416162070.4781.186.camel@revolution.hippie.lan> Content-Type: text/plain; charset="iso-8859-7" Date: Sun, 16 Nov 2014 11:31:58 -0700 Message-ID: <1416162718.4781.192.camel@revolution.hippie.lan> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by ilsoft.org id sAGIVwhN001401 Cc: Hans Petter Selasky , Adrian Chadd , freebsd-current , Steve Kargl , Dag-Erling Sm?rgrav 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: Sun, 16 Nov 2014 18:32:01 -0000 On Sun, 2014-11-16 at 18:23 +0000, Mark R V Murray wrote: > > On 16 Nov 2014, at 18:21, Ian Lepore wrote: > >=20 > > On Sun, 2014-11-16 at 18:17 +0000, Mark R V Murray wrote: > >>> On 16 Nov 2014, at 17:51, Steve Kargl wrote: > >>>=20 > >>> Is there a 'random: device_detach():' missing between the 'umass0' > >>> and 'da0' messages in the last 4 lines. > >>=20 > >> No. At attach time, the RNG grabs some probe entropy. At detach time= it does nothing. > >>=20 > >> M > >=20 > > And yet... Steve has gathered evidence that the system bricks when a > > device is detached with the new entropy-gathering code and doesn't do= so > > prior to that code. What else is the new code doing around detach ti= me? >=20 > Nothing, except possibly harvesting interrupt entropy. I=A2ll promise t= o be > astonished if this is other-than-harmless. >=20 > I=A2d be more suspicious of the harvester thread, but I still can=A2t s= ee how > its hurting :-( >=20 > M The point I'm trying to make here is that you trimmed away the important part of the prior messages and replied only to the part where Steve's debugging efforts were somewhat speculating. The non-speculative part was where he bisected the failure to an exact commit: > > > The problem is caused > > > by r273872. This is the recent random device patch. I have no > > > idea why removing a usb device would cause the system to lock > > > up other than random is probably trying to harvest some entropy. -- Ian