Rusty Russell <rusty@rustcorp.com.au> writes:
> Hi all (esp port maintainers),
>
> In writing the hotplug CPU stuff, Linus asked me to alter the
> boot sequence to "plug in" CPUs. I am shortly going to be sending
> these patches to him now I have got my x86 box to boot with the
> changes.
If to the general SMP case is added the ability to dynamically enable
and disable cpus at runtime, this infrastructure work appears to have
general applicability now. Allowing for example dynamic
enable/disable of HT on P4-Xeons at runtime for example.
> There are two ways to transition: one is to do the minimal hacks so
> that the new boot code works (as per my x86 patch). The other is to
> take into account that the next stage (optional by arch) is to
> actually bring cpus up and down on the fly, and hence actually write
> code that will work after boot as well (as per my ppc patch).
Thinking in terms of physically hot-plugging cpus has me doubt the
actual utility of this code. Instead thinking of dynamically enabling
and disabling processors for debugging sounds very reasonable.
But for the latter something just a little more than minimal hacks
must be implemented. But dynamic cpu enable/disable is definitely
worth it.
Eric
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This archive was generated by hypermail 2b29 : Fri Jun 07 2002 - 22:00:30 EST