Pentium 4 : is smp kernel mandatory ?
James Wilkinson
fedora at westexe.demon.co.uk
Tue Dec 20 23:08:34 UTC 2005
Steven Ringwald wrote:
> From my experience, also, the smp kernels have APIC interrupts enabled,
> whereas the standard uni-processor ones do not. This is especially
> useful if you have a few cards that need to have interrupts serviced
> frequently, like disk controllers/ethernet controllers, etc. I have one
> system that when it is running in XT-PIC mode ( cat /proc/interrupts )
> runs like a dog (ok... a dachshund) , but with APIC turned on, runs more
> like a greyhound.
Couple of points:
* I'm on x86_64, where APICs are presumed reliable and the default even
on single-processor systems.
* Dave Jones says that:
[Uniprocessor APIC] makes certain laptops (and a few desktops) not
boot. At all. The only safe way this can be enabled is with a patch
similar to what is in rawhide kernels right now (With it enabled, but
off by default [boot with 'lapic' to enable it]), though even that
still needs work on some boxes.
-- http://www.livejournal.com/users/kernelslacker/30664.html
That's fairly recent. I don't think the patch has got into FC4 updates
yet, but it might be coming. And may well be there on FC5 anyway.
Hope this helps,
James.
--
E-mail address: james | The opinions expressed herein are not necessarily
@westexe.demon.co.uk | those of my employer, are not necessarily mine, and in
| fact are probably not necessary at all...
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