From owner-freebsd-hackers@freebsd.org  Tue Dec 13 12:41:16 2016
Return-Path: <owner-freebsd-hackers@freebsd.org>
Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7D7BDC74441
 for <freebsd-hackers@mailman.ysv.freebsd.org>;
 Tue, 13 Dec 2016 12:41:16 +0000 (UTC)
 (envelope-from j.deboynepollard-newsgroups@ntlworld.com)
Received: from know-smtprelay-omc-8.server.virginmedia.net
 (know-smtprelay-omc-8.server.virginmedia.net [80.0.253.72])
 by mx1.freebsd.org (Postfix) with ESMTP id EF0671EAF
 for <freebsd-hackers@freebsd.org>; Tue, 13 Dec 2016 12:41:15 +0000 (UTC)
 (envelope-from j.deboynepollard-newsgroups@ntlworld.com)
Received: from [192.168.1.100] ([86.10.211.13])
 by know-smtprelay-8-imp with bizsmtp
 id KQg41u00G0HtmFq01Qg5AE; Tue, 13 Dec 2016 12:40:05 +0000
X-Originating-IP: [86.10.211.13]
X-Spam: 0
X-Authority: v=2.1 cv=N5HUbDJB c=1 sm=1 tr=0 a=SB7hr1IvJSWWr45F2gQiKw==:117
 a=SB7hr1IvJSWWr45F2gQiKw==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10
 a=s5jvgZ67dGcA:10 a=N659UExz7-8A:10 a=hWyk01RRhHyrYV-1E6MA:9 a=pILNOxqGKmIA:10
Subject: Re: NOTE_TRACK, EVFILT_PROC, kqueue, and subreapers
References: <20161201172846.GP3428@protected.rcdrun.com>
 <20161201124118.46778e2b@mydesk.domain.cxm>
 <20161201174837.GR3428@protected.rcdrun.com>
 <20161201125438.15230317@mydesk.domain.cxm>
 <20161206104020.6b2ebb30@eto-mona.office.smartweb.sk>
 <20161206102637.1ddd152a@mydesk.domain.cxm>
 <20161207155638.4b2dd629@eto-mona.office.smartweb.sk>
 <630ace89-e29b-d0d3-9f15-110d8dc3de08@NTLWorld.com>
 <20161208132842.5d7940bd@eto-mona.office.smartweb.sk>
 <f5f47d55-ec8e-75b6-935d-2d0d1111c449@NTLWorld.com>
 <20161211124637.GA17315@stack.nl>
From: Jonathan de Boyne Pollard <J.deBoynePollard-newsgroups@NTLWorld.com>
To: FreeBSD Hackers <freebsd-hackers@freebsd.org>, supervision@list.skarnet.org
Message-ID: <67b4c42e-4e6b-ba64-b8bb-83a8a5dcfba7@NTLWorld.com>
Date: Tue, 13 Dec 2016 12:39:47 +0000
User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:45.0) Gecko/20100101
 Thunderbird/45.1.1
MIME-Version: 1.0
In-Reply-To: <20161211124637.GA17315@stack.nl>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
 <freebsd-hackers.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers/>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 13 Dec 2016 12:41:16 -0000

Jilles Tjoelker:
> This should probably be fixed. 

There's another more insidious bug hiding inside kevent() somewhere that 
causes a kernel abend complaining about a sleeping thread holding a 
non-sleepable lock.  One needs to make fairly heavy use of kevent() in 
order to trigger it, I believe, as I have only seen it so far on systems 
that do.