From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1Lvtfi-00031E-2l for garchives@archives.gentoo.org; Mon, 20 Apr 2009 13:36:30 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id A9A06E0455; Mon, 20 Apr 2009 13:36:08 +0000 (UTC) Received: from rv-out-0708.google.com (rv-out-0708.google.com [209.85.198.243]) by pigeon.gentoo.org (Postfix) with ESMTP id 6D558E0455 for ; Mon, 20 Apr 2009 13:36:08 +0000 (UTC) Received: by rv-out-0708.google.com with SMTP id b17so780213rvf.46 for ; Mon, 20 Apr 2009 06:36:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=3mUlVZwKzvkBQacUP6PqjaIuK3d/MwKNmfJl6Vb5XXw=; b=SKV64AzMrobMD3vUKS4a4iKk5HJpWIfJmZyuv9Fh0eFBr6NIP0vpI+tI0xCZc1BwSn T8Gw2CO4AmzdE1u191UunrFuu33HwVKyfaa/1ie/MdHXSPm9jjlF1J3n64fz+zrdVVF9 tS/6Iv7AcUeC0XYDNbuFL7QBFQcvE6x4ycAUg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=ErEgwehsBjD9GMMPReU3sxfDHN/N1Z205lp0AMsQKTWB6dQuQtKmJIDvRmr65laSwn LHYvdBD9W6wSVTGw29HOuGxuxGKSbC4jXZjBSFhGI9Rfr5c+zIiO0Itycoi0KGjWcwHu Vr257JuQYPDckQBgZvISUgzGkH6K4tScePEiE= Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.141.101.12 with SMTP id d12mr2508055rvm.175.1240234567974; Mon, 20 Apr 2009 06:36:07 -0700 (PDT) In-Reply-To: <200904200948.31303.alan.mckinnon@gmail.com> References: <5bdc1c8b0904191318h4eb5905bh1ab152dc331d6936@mail.gmail.com> <200904200844.43680.alan.mckinnon@gmail.com> <49EC24B0.5010406@gmail.com> <200904200948.31303.alan.mckinnon@gmail.com> Date: Mon, 20 Apr 2009 06:36:07 -0700 Message-ID: <5bdc1c8b0904200636s27f208fbi99288b5f3c64db95@mail.gmail.com> Subject: Re: [gentoo-user] downgrading gcc From: Mark Knecht To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: ad18bdec-71d7-475f-afd6-b3ef21862620 X-Archives-Hash: 8b822e5b26e82cc884bd385cc61e4553 On Mon, Apr 20, 2009 at 12:48 AM, Alan McKinnon w= rote: > On Monday 20 April 2009 09:30:56 Dale wrote: >> That said, it has worked well for me. =C2=A0Everything on my rig is work= ing >> again. =C2=A0If he has to do this downgrade of gcc, then a emerge -e wor= ld >> and everything works again, I'm going to really wonder what the deal is >> with gcc. =C2=A0Just me running into problems is one thing but to have >> someone else have issues as well, that's makes me wonder. =C2=A0Is there >> something funny going on that only affects certain hardware or something >> like that? =C2=A0How would one test it to see what is wrong when it is o= nly a >> couple or a few people? > > It's more likely a compatibility issue between very specific modules or b= its > of code that affect lots of systems. Take for example this elog from the > nvidia drivers: > > =3D=3D=3D > This ebuild installs a kernel module and X driver. Both must > match explicitly in their version. This means, if you restart > X, you most modprobe -r nvidia before starting it back up > =3D=3D=3D > > The interfaces that these things use have never been guaranteed to be sta= ble, > and gcc itself is free (within reason) to lay things out in memory anyway= it > sees fit. You get the same thing with X and it's drivers too. It makes se= nse - > a server and it's drivers should all be part of the same release series a= nd be > built together with the same toolchain for best results. > > You DON'T get this problem with normal packages. You can upgrade and down= grade > cairo all day long if you want and firefox won't care - the API it uses i= s > stable and doesn't change. > > In your case and Mark's, you tried to downgrade something critical but ha= ve no > information about what you should be downgrading to. When you synced port= age, > you lost the information about what was the latest arch and ~arch version= s. > Upgrade is easy - "emerge latest for everything, we know it works"= , but > portage doesn't offer a rollback function so downgrade is much harder. On= ce > someone has figured out $LIST, you can "emerge $LIST" and life is good, b= ut > you don't have $LIST yet. > > Logic tells me you had two problems, and gcc is neither of them. Your box= does > not like latest X for whatever reason (problem 1) but you can't rollback = to > the last working version of everything involved as you don't know what it= is > (problem 2). > > So when all other efforts have failed, downgrade gcc and rebuild everythi= ng is > very likely to fix those problems. > > -- > alan dot mckinnon at gmail dot com > > Alan, Hi. Thanks for your inputs and help. I appreciate it. I think you've covered most of the issues fairly clearly. What you cannot cover is the specifics of my hardware, so I'll try to do this based on what I think I've learned. As best I can tell the failure I'm seeing is a segfault in the Intel VGA driver when doing xv video. OpenGL works fine, and other than xv the Intel driver works fine for me. Using mplayer I can watch videos when I choose OpenGL rendering. All applications fail when using xv, but my initial realization came from mythfrontend which is why this has had a 'mythtv segfaults' title in the past. None the less it's really xv. There are 1 line segfault messages in different log files after the crash pointing at the i915 driver saying it cannot pin an xv buffer in memory. This is apparently known at X.org as I found and posted my results in an existing bug report - one of many on apparently the same issue. Note that if you, or the person who decided to mark xorg-server-1.5 and gcc-4.3.2 stable didn't have Intel hardware, then only if they actually ran xv video apps, they wouldn't have seen this problem. This sort of problem is (to me) a root weakness of the Gentoo package management system. Nothing is really 'stable' as it's not tested against a wide range of known hardware platforms with a know set of test cases before it's marked 'stable' so this sort of thing happens now and again. There is no reason for you to say X isn't stable, or gcc causes problems because everything works on your system. (Or you think it does!) ;-) In my case I *think* the problem showed up only after rebuilding X with gcc-4.3.2 but at this point I've unfortunately sort of lost track of the whole history. I *believe* that gcc got upgraded, I switched my compiler to the newer 4.3.2 version, then an X upgrade came along, got built and started failing. My first attempt at fixing this was to downgrade xorg-server back to 1.3. This failed, but it was built with the newer compiler so it wasn't a real downgrade in the sense of going back to what I had before. I then tried moving to xorg-x11-7.4 which some people at X.org said fixed the problem for them. Unfortunately for me it didn't. Over the years this sort of thing has happened a few times with Gentoo so maybe once every 2 years I'll do an emerge -e system, emerge -e world just to make sure everything is up to date. As I was having problems I decided to do that and move the whole machine to 4.3.2. I got started with that process a couple of days ago. Around that time Michael was having trouble with his USB hardware and the thread had similarities. His solution was to downgrade gcc. However I had already started rebuilding my machine with the new compiler so I couldn't really do that, nor did I want to because if it was a mismatch between something compiled with 4.1.2 and 4.3.2 then it should have been fixed with 4.3.2. Unfortunately moving the whole machine to 4.3.2 didn't solve the problem. xv video still segfaults. This leaves me with a machine that's completely up-to-date but unfortunately doesn't work the way it did for the last 3 years so as an experiment I'm now moving the machine back to 4.1.2. This first pass will get done tonight and maybe by tomorrow I'll know if X-7.4 and the newer Intel driver is functional with 4.1.2. If it is, great. If not, then I suppose I'll try going back to X-7.2/xorg-server-1.3. Don't know. Anyway, I don't think I added any value with this post. Just documentation and possibly some clarity. Cheers, Mark