Re: [PATCH] x86/mm/ident_map: Use full gbpages in identity maps except on UV platform.

[Dave Hansen]

On 3/22/24 10:31, Eric W. Biederman wrote:
>> I'd much rather add synthetic entries to the memory maps that have this
>> information than hack around it by assuming that things are within a
>> gigabyte.
> So this change is a partial revert of a change that broke kexec in
> existing configurations.  To fix a regression that breaks kexec.

Let's back up for a second:

 * Mapping extra memory on UV systems causes halts[1]
 * Mapping extra memory on UV systems breaks kexec (this thread)

So we're in a pickle.  I understand your concern for kexec.  But I'm
concerned that fixing the kexec problem will re-expose us to the [1]
problem.

Steve, can you explain a bit why this patch doesn't re-expose the kernel
to the [1] bug?

1. https://lore.kernel.org/all/20240126164841.170866-1-steve.wahl@xxxxxxx/