Re: [PATCH] mm/pages_alloc.c: Don't create ZONE_MOVABLE beyond the end of a node

[Anshuman Khandual]

Hi Alistair,

On 2/15/22 8:28 AM, Alistair Popple wrote:
> ZONE_MOVABLE uses the remaining memory in each node. It's starting pfn
> is also aligned to MAX_ORDER_NR_PAGES. It is possible for the remaining
> memory in a node to be less than MAX_ORDER_NR_PAGES, meaning there is
> not enough room for ZONE_MOVABLE on that node.

How plausible is this scenario on normal systems ? Should not the node
always contain MAX_ORDER_NR_PAGES aligned pages ? Also all zones which
get created from that node should also be MAX_ORDER_NR_PAGES aligned ?
I am just curious how a node could end up being like this.

- Anshuman