Fedora Summit [LWN.net]

Fedora Summit

Posted Nov 16, 2006 7:37 UTC (Thu) by dwmw2 (subscriber, #2063) [Link]

"Actually, Fedora currently has x86, x86_64, and PPC as primary architectures. In that respect, PPC is already supported. The secondary architecture proposal would bring in things like Sparc, while PPC would essentially be moved from primary to secondary."

Indeed. In fact, although the proposal sounds like a fairly good idea in the long term, it seems like it would be a backwards step in the short term for Fedora on PowerPC and a slap in the face for those who have put a lot of effort into making PowerPC support on Fedora work as well as it does today.

This kind of thing needs to be tested and have the inevitable teething problems ironed out by trying to bring in new ports like Aurora and AlphaCore first, before we try to move already-supported architectures like PowerPC to it.

Hopefully, the Cabal will see this and move forward with most of the proposal but keep PowerPC as one of the 'primary' architectures until we're really sure we can make the change without adverse effects.

Fedora Summit

Posted Nov 19, 2006 13:23 UTC (Sun) by jkeatingatredhat (guest, #40062) [Link]

While it may be a slap in the face to PPC users, its also a slap in the face to Fedora releasers and such when somebody tries PPC first and has a horrible experience. There just aren't enough PPC developers who have enough time in the day to actually care about the platform to go around, and our PPC release suffers. Things like mdraid have been broken for at least 2 releases. Our multilib environment is a joke. Support for hardware such as imac G5s has seen no improvement in years (no video, no support for fan chip control, etc...) I honestly feel that saying we have a PPC release is disingenuous. Its far more a case of 'hey these packages fell out of the build system, lets toss them on an iso'. I try to test the release candidates and betas on my mac mini, but I don't get much (any) other feedback other than what I do. If I'm the only one actually testing the platform before releases, thats not going to work at all. Sure some people (like you David) notice when something is broken, usually far to late in the release cycle to do anything about it. Yes you care, but you don't have the time to actually support it.

Fedora Summit

Posted Nov 19, 2006 13:53 UTC (Sun) by dwmw2 (subscriber, #2063) [Link]

It doesn't surprise me much that mdraid isn't used heavily -- most of the machines we support have only one hard drive in them and RAID isn't going to be a common configuration. But can you let me have the bug number and I'll look into it? I don't think anyone had Cc'd me on the bug so far, or if they did then I missed it.

As a user of PPC64 machines I'm not aware that our multilib environment is 'a joke'. Could you elucidate? It seems to work perfectly well, except for the broken firefox which could trivially be fixed if the package maintainer would wake up.

Yes, some support for certain hardware is still lacking but in general our hardware support is getting much better, and we're also adding support for the new machines which are coming out.

And PowerPC support in userspace in general is good. It's certainly a lot more than "hey these packages fell out of the build system, let's toss them on an iso" -- I for one spend most of my days sitting in front of various Fedora/PowerPC boxes, and I see nothing wrong with Fedora on PowerPC. We make sure package maintainers don't commit stupid non-portable code, and we help out directly with hairier arch-specific issues where necessary (like the PowerPC port of Modula-3 which was required for cvsup).

I certainly do notice if something is broken -- the reason you didn't get much feedback from me in the run-up to the Fedora Core 6 release was that when I installed it on a bunch of PowerPC boxes I didn't find that much was wrong -- I ended up working on Bluetooth stuff instead. And the things that I did fix (like the X bug with PCI domains) I didn't see fit to tell you about directly anyway.

Your perception of the quality of the Fedora/PPC release seems to differ violently from mine; I don't really know why. But I use Fedora/PPC all day, every day and I really don't consider it to be of any lower quality than Fedora on other architectures. And if I did then I would be making time to support it.

Fedora Summit

Posted Nov 19, 2006 14:29 UTC (Sun) by jkeatingatredhat (guest, #40062) [Link]

I don't recall if there is still a bug. I think I filed one around the FC5 days against kernel, don't know what happened. This time around I just noticed that it _still_ doesn't work and gave up on it.

As for multilib, firefox, eclipse, KDE, possibly more all suffered from ppc64/ppc problems. Multilib on ppc is much harder to grasp/produce because of the odd nature of the chip (I say odd as it is different from the mainstream chips). These types of things don't get noticed until its too late, and then we have to scramble to try and fix things as updates.

What "new" machines is Fedora supporting? We don't do iseries for Fedora, just ppc64 and ppc. Since Apple isn't putting out any new machines, which ones are you talking about?

Perhaps we have different views because we see different things. I see and talk to users trying to use PPC Fedora becuase they happen to have an old mac laying around. The experience is generally Not Good for them, whereas if they tried i386 or x86_64 it would have been much better. For you, you're used to the oddities of the platform and expect what you get. Maybe thats the difference.

Fedora Summit

Posted Nov 19, 2006 14:59 UTC (Sun) by dwmw2 (subscriber, #2063) [Link]

I'll go looking for the mdraid bug, or just try to reproduce it here. If you see this kind of thing in future, please could you try to make sure I'm Cc'd? Although it's entirely possible that I was and I just missed it.

As far as I'm aware, Firefox doesn't suffer from generic multilib problems -- it's just badly packaged and doesn't correctly split libs/devel/executable into separate subpackages like everything else does. Hence we end up shipping a PPC64 firefox binary despite the fact that that's a stupid thing to do (since even if we bothered to wire up the object marshalling crap for PPC64 the Java and RealPlayer plugins are still ppc32-only, just like most of the rest of userspace). It was reported long before the release, but the package maintainer hasn't yet got off his wossname and fixed it. I cannot comment on the eclipse and KDE problems since I'm not sure what's going on there. In general, though, the answer for the user is just not to install the 64-bit version of the package in question. On PowerPC we can stick to 32-bit userspace because we don't gain extra registers by going to 64-bit -- we only gain the bloat of 64-bit addresses and longs.

New machines coming soon to Fedora/PowerPC include PlayStation 3, of course, and probably also the rest of the new Cell machines like Toshiba's. IBM's Cell blade has been theoretically supported since FC5 although I haven't had hardware until very recently -- I think Fedora is the only operating system which IBM ships it with.

We'll also support the new Genesi machines as soon as we get them -- there's already a Pegasos ODW on my desk which has been supported since just after FC4, and which is currently running FC6 quite happily. There are other new machines being planned too.

There's also the new pSeries and iSeries machines, but those are a little less interesting. Note that new iSeries have OpenFirmware and are just rebadged pSeries, so they are supported.

I don't think I have different expectations. I expect Fedora on PowerPC to work as well as Fedora on any other architecture, and if I see any way that it doesn't reach that goal I'll work on fixing it. Perhaps there are some particular machines which I haven't seen, on which the installer or the kernel needs some extra love. I'll try to make sure that gets addressed.

But with the possible exception of a few hardware-specific issues on certain machines, Fedora in general is very good on PowerPC. Even cvsup works :)

Fedora Summit

Posted Nov 19, 2006 15:21 UTC (Sun) by jkeatingatredhat (guest, #40062) [Link]

This is one of the huge problems with ppc. It's treated almost like i386/x86_64, but in the wrong way. We're trying to apply the same rules when they just don't work. We need a strong PPC advocate to drive these changes through our tools that deal with building and composing and installing packages, if its even possible. If we just stuck to pure ppc32 this wouldn't be a problem, but ppc64 is just the odd duck. You only want to install ppc32 most the time, but if you HAVE ppc64, prefer ppc64. Our tool set is designed around 'If both are available, install them both' so you wind up with a lot more ppc64 packages than you normally want. However we can't just make them unavilable. We have to figure out some way to actually do what is the Right Thing with our tool set.

As far as new hardware, it would be nice if the release team had access to this new hardware that we're supposed to be supporting. I can't test it, I don't know if it works, I'd really hate to put our name on saying it does. Perhaps if it was on the release testing list, and you had checked it off saying "Yes this is tested and functional" I'd feel much more comfortable. Right now I feel mostly like I'm flying blind.

As far as working as good as other distros, grub for ppc would be nice, as yaboot is rather nasty to expect our normal end users to know how to use (:

Fedora Summit

Posted Nov 19, 2006 15:35 UTC (Sun) by dwmw2 (subscriber, #2063) [Link]

Mostly, the fact that we install a bunch of ppc64 packages is no more of an issue than the fact that we install a bunch of i386 packages on x86_64 installs. Disk is cheap. There's only a few packages which really have problems with that -- and I don't really include firefox in that since it's just a simple packaging bug and easy to fix. The Eclipse one was just a case of being able to find the right version of gcj too, wasn't it? So not using /usr/bin/gcj for both 32-bit and 64-bit versions? I'm fairly sure the KDE one will boil down to something simple too, although I'm not entirely sure what you were referring to there.

Unless I'm missing something, it just isn't that much of an issue. And it certainly doesn't have to be an issue for Fedora, since we don't have to be so strict about shipping every devel package for PPC64. That was a RHEL thing.

You should have access to the Cell blade, and hopefully we'll arrange a PS3 some time soon too. If you don't have access to a Pegasos, I'm sure we can arrange that. Other new hardware I mentioned was 'upcoming', and not yet actually supported -- but obviously we can try to make sure you have access to it as and when it becomes real.

Yeah, grub2 would be cute. I'm happier when end-users don't actually have to touch the bootloader at all though.

Fedora Summit

Posted Nov 19, 2006 16:45 UTC (Sun) by jkeatingatredhat (guest, #40062) [Link]

Well, i386 on x86_64 doesn't hurt as we don't really want to run the i386 binary, we PREFER the x86_64 binary. However on ppc, we would usually prefer the ppc binary. The problem is that we don't really treat the package set any differently across the arches. The same things that are multilib on x86_64 are multilib on ppc64. The same -devel packages we ship for i386 are the same for x86_64 and for ppc64. This is where you run into far far more things been ppc64 on an install than ppc, and you run into the bloat.