SMP kernel on UP machines?

[Emiel Kollof]

* Matthew Dillon (dillon at xxxxxxxxxxxxxxxxxxxx) wrote:
[snip]
> :It might be an idea to allow SMP kernels to boot on UP anyway for
> :distribution purposes. In CURRENT SMP is default and works fine on UP
> :machines. It doesn't slow down the machines much either.

>     FreeBSD-5.x compiles in both the APIC and the ICU interrupt/exception
>     code and falls back to the ICU if it can't find an APIC.
> 
>     DragonFly already uses the per-cpu globaldata access methods on both UP
>     and SMP so it would not be difficult for us to do this too, eventually,
>     but I do not consider it a critical feature. 
> 
>     If you would like to have a go at doing this, or working towards this
>     goal incrementally, I'm fine with bringing the work into the tree.

I'd love to take whack at this, but since I'm not really up to speed
with dfly kernel internals yet, I wouldn't have a clue where to begin :)

David's patch to defaultly enable HTT is a good step I think.

I have the CURRENT source code somewhere (which gets cvsupped
regularily), so I could take a look on how they did the fallback. No
promises of course, but if I whip something up I'll submit it through
the regular channels.

Cheers,
Emiel
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