RFC: Primary architecture promotion requirements

[Jon Masters]

Hello,

On 03/20/2012 12:37 PM, drago01 wrote:
> On Tue, Mar 20, 2012 at 5:34 PM, Brendan Conoboy <blc at redhat.com> wrote:
>> On 03/20/2012 09:21 AM, Ralf Corsepius wrote:
>>>
>>> That said, I considera cross-building environment for secondary arch to
>>> be inevitable, which would at least help for the class of issues, I am
>>> referring to above.
>>
>>
>> I'm a big fan of cross compilation, but introducing it into Fedora in order
>> to support ARM seems unlikely to succeed for too many reasons to go into.
> 
> The reasons are? ....

Fedora generally doesn't cross-compile because you have to minimally run
certain target configuration stuff on the host, and there are many other
hardcoded expectations.

[ Aside - skip this bit - because someone is going to mention it and
take this thread onto a wild tangent, yes you can use distcc hacks, yes,
there is/was Scratchbox, and yes there are many other cute hacks. We
haven't proposed any of this because we want to be boring, we want to
win acceptance by doing what x86 does in as many cases as reasonable. It
isn't reasonable to expect ARM to install using Anaconda on a $25
target, but it is reasonable to expect on-target build ].

>>  Let's figure out how to make native compilation work *better*, how to make
>> koji work *better* when more architectures are involved than just x86.
> 
> The hardware is way slower ... so we can just build on faster hardware
> (x86_64). Which is the only sane way to do it.
> Trying to build on ARM directly is kind of a gimmick but nothing one
> can seriously use to build a whole operating system. (Yes it works but
> it is way to slow).

Well, we've done a number of mass rebuilds, a complete bootstrap from
scratch, and several releases now. So, it might be a "gimmick", but it
works. We need to stop thinking of ARM as it was 10 years ago. This
year, we're going to see systems with 288+ cores in 2U of rack space.
Next year, we're going to see Cortex A-15 systems that will be much
faster still, and the year after, we're going to see 64-bit systems with
at least 8 highly performing cores. It's not all about performance
though. ARM isn't going to beat x86 in a speed race...that is not the
goal. It's about aggregate performance, not individual node performance
at the high end, and about mass availability at the low end.

We can remain an x86-only primary distro. But that won't help address
the longer term problems we will face. I'll spare the hyperbole for the
moment, but I will add that this is a multi-year journey that we want to
begin now. Yes, there are rough edges, yes this is cutting edge stuff,
yes that is precisely what Fedora is all about.

Jon.