From owner-freebsd-current@FreeBSD.ORG Thu Jul 1 11:33:46 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 201A216A4CE for ; Thu, 1 Jul 2004 11:33:46 +0000 (GMT) Received: from smtp003.bizmail.yahoo.com (smtp003.bizmail.yahoo.com [216.136.130.195]) by mx1.FreeBSD.org (Postfix) with SMTP id 030B743D53 for ; Thu, 1 Jul 2004 11:33:46 +0000 (GMT) (envelope-from noackjr@alumni.rice.edu) Received: from unknown (HELO optimator.noacks.org) (noackjr@supercrime.org@70.240.179.20 with login) by smtp003.bizmail.yahoo.com with SMTP; 1 Jul 2004 11:32:59 -0000 Received: from localhost (localhost [127.0.0.1]) by optimator.noacks.org (Postfix) with ESMTP id 507606186; Thu, 1 Jul 2004 06:32:59 -0500 (CDT) Received: from optimator.noacks.org ([127.0.0.1]) by localhost (optimator.noacks.org [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 02387-01; Thu, 1 Jul 2004 06:32:57 -0500 (CDT) Received: from compgeek.noacks.org (compgeek [192.168.1.10]) by optimator.noacks.org (Postfix) with ESMTP id C6F676140; Thu, 1 Jul 2004 06:32:57 -0500 (CDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by compgeek.noacks.org (8.12.11/8.12.11) with ESMTP id i61BWvV0032672; Thu, 1 Jul 2004 06:32:57 -0500 (CDT) (envelope-from noackjr@alumni.rice.edu) Message-ID: <40E3F669.80408@alumni.rice.edu> Date: Thu, 01 Jul 2004 06:32:57 -0500 From: Jon Noack User-Agent: Mozilla Thunderbird 0.7.1 (X11/20040629) X-Accept-Language: en-us, en MIME-Version: 1.0 To: noackjr@alumni.rice.edu References: <20040701061818.GA80579@lucky.net> <20040701063105.GA20785@xor.obsecurity.org> <200407011617.03053.doconnor@gsoft.com.au> <20040701083434.GA83951@atrbg11.informatik.tu-muenchen.de> <40E3DE2D.3020204@alumni.rice.edu> <20040701103535.GA84499@atrbg11.informatik.tu-muenchen.de> <40E3EBD2.2020106@alumni.rice.edu> <40E3EF47.5090007@alumni.rice.edu> <40E3F3DA.1050702@alumni.rice.edu> In-Reply-To: <40E3F3DA.1050702@alumni.rice.edu> Content-Type: multipart/mixed; boundary="------------090406000108090201010404" X-Virus-Scanned: by amavisd-new at noacks.org cc: "Bjoern A. Zeeb" cc: FreeBSD current mailing list cc: Daniel Lang Subject: Re: LOR (vm object - swap_pager swhash) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: noackjr@alumni.rice.edu List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Jul 2004 11:33:46 -0000 This is a multi-part message in MIME format. --------------090406000108090201010404 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit On 07/01/04 06:22, Jon Noack wrote: > On 07/01/04 06:02, Jon Noack wrote: > >> On 07/01/04 05:47, Jon Noack wrote: >> >>> Perhaps the best bet is to add a FAQ. The FAQ would point to >>> Bjoern's site and the LOR-message would point to the FAQ entry. >> >> >> Again, my docproj foo is weak, but see the attached FAQ. > > > You have to uninstall the xhtml-1.1 port to get docproj to work?!? > Whatever... > > In any case, here's what it would look like: > http://www.noacks.org/freebsd/book.html#LOCK-ORDER-REVERSAL Might help to close the paragraph. Also, add a link to the witness man page. I swear this is the last email... Jon --------------090406000108090201010404 Content-Type: text/plain; name="lor-faq.diff" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="lor-faq.diff" Index: book.sgml =================================================================== RCS file: /home/ncvs/doc/en_US.ISO8859-1/books/faq/book.sgml,v retrieving revision 1.626 diff -r1.626 book.sgml 4381a4382,4426 > > > > What is a lock order reversal? > > > > &a.rwatson; answered this question very succinctly on > the freebsd-current list in a thread entitled url="http://docs.freebsd.org/cgi/getmsg.cgi?fetch=65165+0+/usr/local/www/db/text/2003/freebsd-current/20031221.freebsd-current">lock > order reversals - what do they mean? > >
> &a.rwatson; on freebsd-current, December 14, > 2003 > > These warnings are generated by Witness, a run-time lock > diagnostic system found in FreeBSD 5-CURRENT kernels (but > removed in releases). You can read more about Witness in the > &man.witness.4; man page, which talks about its capabilities. Among > other things, Witness performs run-time lock order verification > using a combination of hard coded lock orders, and run-time > detected lock orders, and generates console warnings when lock > orders are violated. The intent of this is to detect the > potential for deadlocks due to lock order violations; it's worth > observing that Witness is actually slightly conservative, and so > it's possible to get false positives. In the event that Witness > is accurately reporting a lock order problem, it's basically > saying "If you were unlucky, a deadlock would have happened > here". There are a couple of "well known" false positives, > which we need to do a better job of documenting to prevent > spurious reports. The non-well-known ones typically correspond > to bugs in newly added locking, as lock order reversals usually > get fixed pretty quickly because Witness is busy generating > warnings :-). >
> > > See url="http://sources.zabbadoz.net/freebsd/lor.html">Bjoern > Zeeb's lock order reversal page for the status of > known lock order reversals. > > > --------------090406000108090201010404--