Re: [PATCH] x86/boot: Reorganize and clean up the BIOS area reservation code

From: Ingo Molnar
Date: Thu Jul 21 2016 - 12:18:15 EST

* Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:

> It would be very easy to implement this if we could handle overlapping memblocks
> precisely or set a lower limit on the memblock allocator. Then we could block
> off everything below 1MB or 2MB very early and then unblock it or temporarily
> change the lower limit and ask for a single page for the trampoline after that.

So my suggestion was/is to _permanently_ allocate the SMP trampoline page, and
leave it also reserved.

'Reserving' a memory area is really just a kernel internal matter. We can still
use it. No need to unreserve/allocate/re-reserve ... unless I'm missing something.