On 24.03.21 13:10, Michal Hocko wrote:

On Wed 24-03-21 13:03:29, Michal Hocko wrote:

quoted

On Wed 24-03-21 11:12:59, Oscar Salvador wrote:

[...]

an additional remark

quoted

quoted

- online_pages()->move_pfn_range_to_zone(): Accounts for node/zone's spanned pages
- online_pages()->zone->present_pages += nr_pages;

I am pretty sure you shouldn't account vmmemmap pages to the target zone
in some cases - e.g. vmemmap cannot be part of the movable zone, can it?
So this would be yet another special casing. This patch has got it wrong
unless I have missed some special casing.

It's a bit unfortunate that we have to discuss the very basic design 
decisions again.

@Oscar, maybe you can share the links where we discussed all this and 
add some of it to the patch description.

I think what we have right here is good enough for an initial version, 
from where on we can improve things without having to modify calling code.

-- 
Thanks,

David / dhildenb