From owner-freebsd-hackers@FreeBSD.ORG Sun Jul 6 11:43:20 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1D4181065670 for ; Sun, 6 Jul 2008 11:43:20 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.freebsd.org (Postfix) with ESMTP id E60AE8FC0C for ; Sun, 6 Jul 2008 11:43:19 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id 6796646C48; Sun, 6 Jul 2008 07:43:19 -0400 (EDT) Date: Sun, 6 Jul 2008 12:43:19 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Matthias Apitz In-Reply-To: <20080704124227.GA10264@rebelion.Sisis.de> Message-ID: <20080706124135.C44832@fledge.watson.org> References: <20080704124227.GA10264@rebelion.Sisis.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-hackers@freebsd.org Subject: Re: kernel HEAD && userland 7.0-REL? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Jul 2008 11:43:20 -0000 On Fri, 4 Jul 2008, Matthias Apitz wrote: > I'm running a RELENG_7 kernel and a userland as 7.0-REL on one of my > laptops; I've been asked to check if a given driver problem in RELENG_7 is > as well with HEAD... can I update the kernel to HEAD and let the userland > (and all my compiled ports) as 7.0-REL; I know that this is not the > intention, but it would cost me a lot of work if I should compile as well > ~200 ports.... As a general rule, running old userspace on a new kernel works pretty well, but you should expect certain types of things to not work -- for example, monitoring tools that expect the kernel layout of data structures to be unchanged. Within a particular -STABLE branch this is a bit less volatile, but as you go from, say, 6-STABLE to a 7-STABLE kernel, the chances that some of the more obscure options to netstat, etc, will not work are pretty high. Likewise, be careful to disable any third-party kernel modules that may require recompiling but aren't caught by the base system build, or you'll get a nasty surprise when they panic. :-) Robert N M Watson Computer Laboratory University of Cambridge