Re: [PATCH 1/2 v2] x86: add max_addr boot option

Kamezawa Hiroyuki
2012-06-13T02:23:58Z

(2012/06/13 1:10), H. Peter Anvin wrote:
> If what you care about is nodes, why not have an option to specify a map?
>

At the first time of our project, we discussed passing node-id as boot option.
But, we found Node-ID is just determined by the pxm ID order in SRAT. That means,
we and our firmware team need to take care of the order of SRAT. But that node-ID
v.s. SRAT relationship is just determined by implemenation, there is no spec,
we thought we can't keep this way in future.

The second thought was specifying PXM. But, with hardware-partitioning-system,
dynamic implementation of SRAT for a partutuion is very confusing...

Then, alternative idea was using mem= boot option. Because our partition system
has fixed address range per each node, it works well.

But now, we know mem= boot option is buggy....it acts as max_addr= option, we
have concerns that 'someone may fix mem= option as sane as ia64. because it's buggy".

We'd like to fix mem= boot option by ourselves and preserve old behavior with max_addr=
boot option, which ia64 has.

Thanks,
-Kame