Re: [SLE] Repository for kernel 2.6.17?

On Tuesday 12 September 2006 00:01, Jan Engelhardt wrote:
* Sylvester Lykkehus <zly@xxxxxxxxxxxxxx> [09-11-06 15:47]:
I don't see any kernel-smp on that location, are they available
somewhere else, or is it indeed a SMP enabled kernel ?

*all* kernels are now smp enabled, at least 2.6.18*.

I heard rumors a bit back that the kernel guys finally found the reason
the kernel needed special compiling for smp vs. non-smp. Some dumb
programming error that had been in the kernel for eons. The correction
resulted in one kernel working on both smp and non-smp processors. So,
maybe the rumor was true?

I'd rather say this:
http://lwn.net/Articles/164121/

Quoting:....
A more interesting - and more controversial - feature of this patch is that,
when the kernel is converted between the SMP and uniprocessor mode, the
overwritten instructions are remembered. At some point the the future, then,
the alternatives code can reverse the change, switching the kernel back to
the full SMP implementation. The code is then run whenever a CPU hotplug
event happens, optimizing the kernel for the system's new configuration. A
system can be initially booted with a single processor, and the alternatives
code will edit out all of the SMP-related instructions. If another processor
is added later on, the kernel will be automatically converted back into a
fully SMP-capable mode.
---end-quote.

I distinctly remember playing with BeOS on a dual processor system.
They had an option to shut down (more likely simply fail to use) either
processor. There was a button you could click and watch your load
jump to the remaining processor and the clicked one fall to zero.

I never found a valid use for this but it was cool to watch.



--
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John Andersen

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