On Fri, Nov 17, 2023 at 12:08:31AM +0100, David Hildenbrand wrote:
On 14.11.23 19:02, Sumanth Korikkar wrote:
Hi All,
The patch series implements "memmap on memory" feature on s390 and
provides the necessary fixes for it.
Thinking about this, one thing that makes s390x different from all the other
architectures in this series is the altmap handling.
I'm curious, why is that even required?
A memmep that is not marked as online in the section should not be touched
by anybody (except memory onlining code :) ). And if we do, it's usually a
BUG because that memmap might contain garbage/be poisoned or completely
stale, so we might want to track that down and fix it in any case.
So what speaks against just leaving add_memory() populate the memmap from
the altmap? Then, also the page tables for the memmap are already in place
when onlining memory.
we do have page_init_poison() in sparse_add_section() which should be
handled later then. not in add_pages()