From owner-freebsd-hackers@FreeBSD.ORG Sun Jul 6 20:04:10 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 C61111065683 for ; Sun, 6 Jul 2008 20:04:10 +0000 (UTC) (envelope-from pisymbol@gmail.com) Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.187]) by mx1.freebsd.org (Postfix) with ESMTP id A66C28FC14 for ; Sun, 6 Jul 2008 20:04:09 +0000 (UTC) (envelope-from pisymbol@gmail.com) Received: by nf-out-0910.google.com with SMTP id h3so647061nfh.33 for ; Sun, 06 Jul 2008 13:03:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=+XoUtya8j68ubXjeojpuk05vYaiTgaa2syOLT3epfhM=; b=UOfixoE++mxoeFXXYCYdlp09LU1MnaSQuNqJ6x6yvs1UDWYStLkNvkrGMgUV5ucH8u oHP36npSqtGMIGXeB9MwlsDyNRVfLvzB5cTIDVnr1eouyHSmLXqBxdusR1+tYVvYf2hd sl+cXWMM1z9qpE+mXZTTg++ya3gMNQgmnj3rw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=mZ+Isz/vpU18hAuzG+QWxER/8diAVECADG0OArVa8ZBmDK1mExP6TZ/Pn9HVd/iwD3 VApvkMk6TZTl8BcvQtTlMpEdddfeBg5zNRpeRzzwaxKJJiRinFlVN/l7PDoIR216jp9w 0v2uFsZgPEzgbWzP+J+Qraxok0prWDgqJcTuU= Received: by 10.210.16.11 with SMTP id 11mr2425168ebp.187.1215374628836; Sun, 06 Jul 2008 13:03:48 -0700 (PDT) Received: by 10.210.34.1 with HTTP; Sun, 6 Jul 2008 13:03:48 -0700 (PDT) Message-ID: <3c0b01820807061303m4afde83dhfe0cd693b6a235cc@mail.gmail.com> Date: Sun, 6 Jul 2008 16:03:48 -0400 From: "Alexander Sack" To: "Robert Watson" In-Reply-To: <20080706124135.C44832@fledge.watson.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080704124227.GA10264@rebelion.Sisis.de> <20080706124135.C44832@fledge.watson.org> Cc: freebsd-hackers@freebsd.org, Matthias Apitz 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 20:04:10 -0000 On Sun, Jul 6, 2008 at 7:43 AM, Robert Watson wrote: > > 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, really good point. I ran into this exact problem not so long ago (third-party driver not supporting newer kernels, chaos ensued). I also think Mike's nextboot suggestion is one I (and others) should pay attention too. I tend to just install my test kernel blindly and if it fails, reboot and interrupt the boot, etc. - I will use nextboot for sure! -aps