From owner-svn-src-head@FreeBSD.ORG Mon Sep 13 19:24:26 2010 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DFF27106566C; Mon, 13 Sep 2010 19:24:26 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id B1A898FC0C; Mon, 13 Sep 2010 19:24:26 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 613C046B5C; Mon, 13 Sep 2010 15:24:26 -0400 (EDT) Received: from jhbbsd.localnet (smtp.hudson-trading.com [209.249.190.9]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 7B9AA8A03C; Mon, 13 Sep 2010 15:24:25 -0400 (EDT) From: John Baldwin To: Matthew D Fleming Date: Mon, 13 Sep 2010 15:18:38 -0400 User-Agent: KMail/1.13.5 (FreeBSD/7.3-CBSD-20100819; KDE/4.4.5; amd64; ; ) References: <201009131848.o8DImNU6024992@svn.freebsd.org> In-Reply-To: <201009131848.o8DImNU6024992@svn.freebsd.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201009131518.38829.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Mon, 13 Sep 2010 15:24:25 -0400 (EDT) X-Virus-Scanned: clamav-milter 0.95.1 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=4.2 tests=AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r212572 - in head/sys: dev/cxgb kern sys vm X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Sep 2010 19:24:27 -0000 On Monday, September 13, 2010 2:48:23 pm Matthew D Fleming wrote: > Author: mdf > Date: Mon Sep 13 18:48:23 2010 > New Revision: 212572 > URL: http://svn.freebsd.org/changeset/base/212572 > > Log: > Revert r212370, as it causes a LOR on powerpc. powerpc does a few > unexpected things in copyout(9) and so wiring the user buffer is not > sufficient to perform a copyout(9) while holding a random mutex. > > Requested by: nwhitehorn Hmmm, that is going to break several other sysctls as well then. Many sysctls use sysctl_wire_old_buffer() explicitly so that they can then call SYSCTL_OUT() without dropping a lock. The pcblist sysctls do this for example I think. In general code in the kernel assumes that copyout(9) to/from a wired buffer is safe while holding mutexes or rwlocks. -- John Baldwin