Re: [PATCH] [RESEND] x86_64: add memory hotremove config option
From: Andi Kleen
Date: Mon Sep 08 2008 - 07:27:00 EST
> Sorry, by "block", I really mean spin I guess. I mean that the CPU will
> be forced to stop executing due to the page fault during this sequence:
It's hard for NMIs at least. They cannot execute faults.
In the end you would need to define a core kernel which
cannot be remapped and the rest which can and you end up
with even more micro kernel like mess.
> ptep_clear_flush(ptep) <--- from here
> set_pte(ptep, newpte) <--- until here
>
> for prot RW, the window also would include the memcpy, however if that
> adds too much latency for execute/reads, then it can be mapped RO first,
> then memcpy, then flushed and switched.
>
>
> > Then that would be essentially a hypervisor or micro kernel approach.
>
> What would be? Blocking in interrupts? Or non-linear kernel mapping in
Well in general someone remapping all the memory beyond you.
That's essentially a hypervisor in my book.
-Andi
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