On Tue, Mar 20, 2012 at 5:50 PM, Brendan Conoboy <blc(a)redhat.com> wrote:
On 03/20/2012 09:37 AM, drago01 wrote:
>>
>> 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? ....
Okay, why not?
The ones off the top of my head, and this is by no means exhaustive:
1. Fedora Policy (Which I imagine is based on the technical foundation of
the following 5+ points and others I'm unaware of).
I said "technical" so lets take policy aside ...
2. Many packages assume a native execution environment which will not
exist.
Incredible undertaking to move 11000 packages to cross compilation
framework.
qemu? Should be still faster then doing the whole build on arm.
3. Absence of arm-linux cross compilers in the distribution.
Err yeah but nothing that can't be fixed.
4. If there were arm-linux cross compilers, how do you keep them in
sync
with native gcc?
Build from the same srpm.
5. Where does the sys-root for an arm-linux cross compiler come
from?
6. Would koji then be native/cross ambidextrous? Who is going to do that?
No real answers to them yet but fixing them seems to be easier then
"make arm as fast as x86_64".
For all these reasons and more we're not proposing cross
compilation for
ARM. Just doing so defies what it means to be PA.
We should somehow define what a PA is then. I wouldn't have added
"built on native hardware" because that does not really seem to
matter.
> 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).
In couple years the hardware is going to be surprisingly comparable or
exceed to what you're see on x86, especially as the number of cores
skyrockets while the GHz continue to climb.
Might be true might be not ... we are talking about the next couple of
months not years.
It's not a gimmick, we're just
preparing for the future before it gets here. The only problem we face is
that those cores are in multiple CPUs so we can't 'make -j' our way out of
the build system problem.
Huh? Not sure I follow here.
Also I am not opposed to having ARM as PA, I just don't really think
we should do it the way it is proposed here (build on hardware that is
way slower then the rest of the builders).