Red Hat: no desktop products coming [LWN.net]

Red Hat: no desktop products coming

Posted Apr 20, 2008 21:20 UTC (Sun) by nix (subscriber, #2304)
In reply to: Red Hat: no desktop products coming by mmarq
Parent article: Red Hat: no desktop products coming

Why not ?... if costumers what they want is a particular app, why not offer them what they want and take a small profit out of it ?... if i remember FOSS philosophy is not opposed to profit...

No, but it is opposed to distributing closed-source vendors' code for them. I'd have thought this would be obvious.

Nuclear facilities and weapon building

Well, the nuke embedded systems are classic examples of vertical apps, passed around among interested parties (largely by technology transfer and outright spying). The toolchains that build those, well, I'd be surprised to find all of them devoid of GNAT, which is of course free as in copyrighted by FSF and based on code written by RMS :)

Politics!?... Compiler specifics won't depend of IL, but IL should depend of compiler specifics, is that it ?

RMS's objection was that a persistent IL in any form would provide an irresistible temptation to others to provide ways to effectively replace parts of GCC with non-free software.

He was eventually persuaded that enough other free compilers now exist that GCC alone cannot prevent this, and that further an IL which is written with no particular attempt to make it GCC-independent is unlikely to be used by many non-free GCC-replacers. We shall see if this is right :)

But why can't GCC co-opt something like LLVM which is copyleft BSD ?

Last I looked LLVM's copyright wasn't owned by the FSF (though neither is ecj, which is now used as GCJ's parser). There is substantial feedback between LLVM and GCC: some people work on both projects. Co-opting it whole is probably impractical, the architectures are too different: if you did that you'd basically end up with LLVM, in which case why not use that to start with?

But very important to have such kind of infrastructure independent of language front end and of ISA backend representations IMHO...

Well, duh. Depending on how you look at it, this has been present since the early 2000s (in the form of tree-ssa and the GENERIC and GIMPLE representations), or since the start of GCC (in the form of RTL). You simply can't write a multilanguage or multitarget compiler without some form of IR.

if that IL is not completely suitable change it...

It's hard to make major changes to an IR once you have dozens of passes depending on it. e.g. the mem-ssa changes (which were changes to *representation* not semantics) were really quite difficult and substantial. Making changes to semantics, particularly the semantics of something like RTL which is wired into the quasidocumented and heavily-coupled guts of Ancient GCC, is dramatically harder.

Seems a contradiction. IL should be more important IMHO. Modular "optimization" much more flexible and practical. LLVM was just an example. Its not perfect. What is not good about it, could be made much better in another similar approach... Compiler approaches IMHO are in need of a serious overhaul.. new ideas!... because the chips that are coming, and the development models needed are different from the usual... the clock is ticking, HW manufacturers wont wait for long debates... if FOSS loses this boat... we'll came to LWN, but with nostalgia...

I'm afraid this makes no sense at all to me. Why would hardware manufacturers care how code was distributed?

Rereading your older posts in this thread, you seem to be suffering under the misconception that there's some sort of magic representation we could use to ship J. Random Unix Program so that it would Just Work, only faster, on massively multiprocessor systems, GPUs, and so on. This simply isn't the case. Making programs capable of effective massive parallelization requires pervasive algorithmic changes: worse, the field is young, and we don't even know in many cases what the right algorithms are (e.g. lockless algorithms are obviously preferable to locky ones, but so far comparatively few lockless algorithms are known, and they're substantially harder to understand than those that use locks).

It's trivial, in a built-from-source distro like gentoo, to probe hardware requirements and set compiler flags appropriately (although this is also largely pointless with GCC on x86 these days thanks to -march=native, -mtune=generic and friends). But magically turning single-threaded CPU hogs into multithreaded processes that run on your graphics card isn't going to happen anytime soon, I'm afraid.

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Red Hat: no desktop products coming

Posted Apr 21, 2008 2:44 UTC (Mon) by mmarq (guest, #2332) [Link]

"" No, but it is opposed to distributing closed-source vendors' code for them. I'd have
thought this would be obvious.""

You mean,... who ever puts in their repositorys win4lin or the free vmware player that anyone
can download and install for free... ha! not to mention the commercial version of crossover
that always lags several months what is then release to the wine tree... is gonna to be
banished from the community. I 'm a strong supporter of FOSS, under my possibilities probably
is not you that is more supportive... but i really find that an hypocrisy...

Happily is not true. Doesn't anyone offer close source apps ?... Linspire CNR ?, Mandriva Club
?,... Xandros ?.... i haven't really checked but i believe they do. ah!... Adobe reader is not
FOSS and i have installed it from my distro repository...

"" RMS's objection was that a persistent IL in any form would provide an irresistible
temptation to others to provide ways to effectively replace parts of GCC with non-free
software. ""

And so what!?... if GCC gets in the same kind of agglutination paradigma, that Linux with its
LSF gets with everybody wanting to participate eagerly including big industry players, then
GCC has nothing to fear, because GCC will always be better... let them try !?

Better GCC can be in GPLv3, and be very watchful of the Industry lobbying and influence. What
GCC should not do, IMHO, is be in the fear and refuse splendid ideas and and potential tech
innovations because of the fear that other can do of abuse.

I'm not implying that GCC and RMS should loose their principals... never!

What i'm saying is that GCC and RMS have nothing to fear from abuse if they can get the clear
technologic superiority...

Its like the so much talked about court of law prove about GPL validity. People have abused
GPL several times, but abusers have always steped back,... FOSS is too dynamic and technologic
acute for law suits. What is the point of litigation even if an abuser think in his mind that
he can win , if by the time it is settled, things have moved so rapidly that the pieces of
code involved don't make sense anymore?...

Now if GCC is left behind technologically, it will be much more prone to abuse, than if it
risks and gets into techs that are clearly not screen free from abuse.

ILs... nothing should be set in stone forever, specially an IR format... there can be always
jumps... new headings... new ideas...

"" I'm afraid this makes no sense at all to me. Why would hardware manufacturers care how code
was distributed? ""

Well that is the whole point, they don't.... but the whole idea about "Fusion" style chips,
and "streaming" optimizations being for ATI/SSE5 or Intel AVX or whatever Nvidia cooks, is
going to be here fast, and its going to catch the whole set on fire... multicore, manycore,
will be even on entry level desktops and wont take that many years to be in embedded...

Many users will be wonting "streaming", i want it too... the current approach of GCC doesn't
seam to me completely adequate... its not an insult... its only a temporary and minor issue i
want to believe...

Get "bold" please.

Red Hat: no desktop products coming

Posted Apr 21, 2008 6:57 UTC (Mon) by nix (subscriber, #2304) [Link]

You mean,... who ever puts in their repositorys win4lin or the free vmware player that anyone can download and install for free... ha! not to mention the commercial version of crossover that always lags several months what is then release to the wine tree... is gonna to be banished from the community.

No, simply that free software vendors are unlikely to do it, because a compiler intermediate representation of Adobe Whatever is not free software.

GCC has nothing to fear, because GCC will always be better...

Unfortunately, GCC is not better at single-machine optimization than many vendor compilers (although it is getting better). So this really would be a temptation. (What's worse is the temptation of hooking up a new frontend, and this has been tried: if GCC had been partitionable as you suggest, we wouldn't have a free Objective C frontend today.)

Better GCC can be in GPLv3

sigh. GCC has been GPLv3 since that license's release. Do pay attention.

Now if GCC is left behind technologically, it will be much more prone to abuse, than if it risks and gets into techs that are clearly not screen free from abuse.

If GCC gets left behind technologically, nobody will want to stick their favourite proprietary frontend on it.

(Anyway, it's not me you've got to convince; it's RMS. Getting RMS to change his mind when he has reasons to think one thing is hard. Good luck. I'd not even bother trying until your ideas are much more coherently presented.)

Get "bold" please.

I just don't think optimizers are magic. You seem to think they are. (Again, the magic autoparallelize-everything optimizer does not exist. It's not just that oh look nobody's written one: nobody knows how such a thing might be written.)

Red Hat: no desktop products coming

Posted Apr 21, 2008 16:46 UTC (Mon) by mmarq (guest, #2332) [Link]

Really don't understand your objections!...

"" No, simply that free software vendors are unlikely to do it, because a compiler
intermediate representation of Adobe Whatever is not free software.""

Neither is the binary, even packed in RPM format, that Adobe does using GCC, and that distros
include in their repositorys.

"" Unfortunately, GCC is not better at single-machine optimization than many vendor compilers
(although it is getting better). So this really would be a temptation. (What's worse is the
temptation of hooking up a new frontend, and this has been tried: if GCC had been
partitionable as you suggest, we wouldn't have a free Objective C frontend today.) ""

Why not ?... is the Objective C frontend close source ?... Doesn't LLVM include an open source
Objective C/C++ frontend, and isn't LLVM partitioned and modular like you say ?

"" If GCC gets left behind technologically, nobody will want to stick their favourite
proprietary frontend on it.""

So its better that way, be left behind so that nobody will be tempted to abuse, is that it
?... my way or no way ?

But if that happens wouldn't it be a clear GPL violation ?... Why would anybody risk it, if
they can enjoy all the advantages of distributed development and the power that FOSS enjoys,
instead of law suits ?

Still i believe the biggest problem would be in the backend... But taking an example, isn't
AMD CTM/CAL open sourced ?... what is so terrible wrong about cooperation so that the lower
parts of that driver could be modular and treated by GCC the same way that Linux treats
firmware ?... (only an example because i don't know if CTM/CAL is really open sourced all the
way into the clear naked metal)

They might do exactly that, putting that lower level as firmware for HW, if they feel that
they are being accepted. And who says AMD, can say Intel or Nvidia...

"" (Anyway, it's not me you've got to convince; it's RMS. Getting RMS to change his mind when
he has reasons to think one thing is hard. Good luck. I'd not even bother trying until your
ideas are much more coherently presented.) ""

I don't have to convince nobody. Time is a cure for everything.

I'm sorry about the coherency anyway. But i think what i'm saying is that, is about time, to
GCC to open a new development tree!... yes, like in the time there was a stable and
development Linux tree. Certainly is not that easy, nor even magic or something like that...
but certainly would prove the power of GCC.

The current GCC tree can still be supported for many more years...

But what is the point of supporting archaic language front ends, that only 3 guys are using,
and one is 80 years old and is forgetting constantly where the return key is ?!...

That way would be close to impossible for GCC to evolve, there would be more PITA than
anything else, and tech forums would be full of "exposed" technical impediments and hurdles...
nobody would bother even to start... the new tree should tackle new problems and new ideas!...

Red Hat: no desktop products coming

Posted Apr 21, 2008 19:21 UTC (Mon) by nix (subscriber, #2304) [Link]

Neither is the binary, even packed in RPM format, that Adobe does using GCC, and that distros include in their repositorys.

Distros that don't ship non-free software don't ship that binary (assuming you mean Flash). (Is it even redistributable? I thought most distros shipped a script that downloaded it from Adobe.)

if GCC had been partitionable as you suggest, we wouldn't have a free Objective C frontend today.)
Why not ?... is the Objective C frontend close source ?

No, but had it been easy to get it to emit something that GCC's backend could have processed, the frontend would have been closed-source. (This is a matter of historical record by this point. If I'm wrong, Joe Buck can tell me I'm full of crap, if he's still reading.)

But if that happens wouldn't it be a clear GPL violation ?

If GCC emits a stable intermediate representation (as it would have to for distros to usefully ship things in that form), and accepts that representation for further processing, then having some closed-source program emit it probably would not be a GPL violation: at least it would be very hard to prove. This is why GCC doesn't, and won't, emit a stable intermediate representation. (The representation used for link-time optimizations is, as I understand it, by design not stable enough to be usefully emittable by anything but GCC, and definitely not intended as a medium to transport code between machines in.)

isn't AMD CTM/CAL open sourced ?... what is so terrible wrong about cooperation so that the lower parts of that driver could be modular and treated by GCC the same way that Linux treats firmware ?

This is already doable by implementing a GCC backend that accepts whatever representation the CTM/CAL code generator accepts. It's just like cross-compilation, in fact it is cross-compilation: exactly the same mechanism is used to generate code for the Cell SPUs.

But it's not something that magically kicks in: there'd be a different version of a package that had code like this in it, or perhaps a new glibc hwcap and corresponding subdirectories searched by the dynamic linker for shared libraries containing object files in the appropriate form.

I don't have to convince nobody. Time is a cure for everything.

If you want to get GCC to emit a stable intermediate representation, you have to convince RMS :)

Red Hat: no desktop products coming

Posted Apr 21, 2008 3:28 UTC (Mon) by mmarq (guest, #2332) [Link]

I forgot to mention;

"" But magically turning single-threaded CPU hogs into multithreaded processes that run on
your graphics card isn't going to happen anytime soon, I'm afraid. ""

Of course not. Wild guess, but i believe that 50% of what is in a normal desktop installation,
in a foreseeable future, wont see any vectorization and only mild parallelization if any at
all.

Start with the obvious ones

So benchmarks, of which i urled one in my first post show possibilities  of more than 2 orders
of magnitude improvement, for hand tuned and for that code base that can benefice higly.

All in all, if only 50% of the code base installed gets improvements of only a little more
than 1 order of magnitude average, in overall the improvement can still be in the various of
thens of % (Amdahl law).

And here is the beauty of source code!. It shouldn't just be a recompile. FOSS permits always
some sort of hand tunning... start with the obvious,  start conservative... i don't think that
everything will be possible... but in the end it can prove more than worthed.

Red Hat: no desktop products coming

Posted Apr 21, 2008 6:59 UTC (Mon) by nix (subscriber, #2304) [Link]

If you use OpenMP (which has a really nasty #pragma-based syntax but works 
quite well, and which recent GCCs have native support for) then there is 
no need to recompile at all: you just compile with OpenMP, and the program 
itself probes for the number of cores at startup. I see no reason why an 
enhanced OpenMP runtime couldn't probe for a GPGPU and run bits on there 
if it wanted to, all without any need for this elaborate IR-shipping you 
seem to be discussing.

Red Hat: no desktop products coming

Posted Apr 21, 2008 17:01 UTC (Mon) by mmarq (guest, #2332) [Link]

Others also obvious targets are Intel open sourced IBB, and AMD open sourced "framewave"...
and you can bet that similar approaches would be getting here like the rain.