On 07.08.24 13:32, David Hildenbrand wrote:
On 07.08.24 00:14, Pasha Tatashin wrote:
nid is needed during memory hot-remove in order to account the
information about the memmap overhead that is being removed.
In addition, we cannot use page_pgdat(pfn_to_page(pfn)) during
hotremove after remove_pfn_range_from_zone().
We also cannot determine nid from walking through memblocks after
remove_memory_block_devices() is called.
Therefore, pass nid down from the beginning of hotremove to where
it is used for the accounting purposes.
I was happy to finally remove that nid parameter for good in:
commit 65a2aa5f482ed0c1b5afb9e6b0b9e0b16bb8b616
Author: David Hildenbrand <david@xxxxxxxxxx>
Date: Tue Sep 7 19:55:04 2021 -0700
mm/memory_hotplug: remove nid parameter from arch_remove_memory()
To ask the real question: Do we really need this counter per-nid at all?
Seems to over-complicate things.
Case in point: I think the handling is wrong?
Just because some memory belongs to a nid doesn't mean that the vmemmap
was allocated from that nid?
Wouldn't we want to look at the actual nid the vmemmap page belongs to
that we are removing?
--
Cheers,
David / dhildenb
