[RFC PATCH] mm/page_alloc: Add PCP list for THP CMA

[Juan Yescas]

Hi David/Zi,

Is there any reason why the MIGRATE_CMA pages are not in the PCP lists?

There are many devices that need fast allocation of MIGRATE_CMA pages,
and they have to get them from the buddy allocator, which is a bit
slower in comparison to the PCP lists.

We also have cases where the MIGRATE_CMA memory requirements are big.
For example, GPUs need MIGRATE_CMA memory in the ranges of 30MiB to 500MiBs.
These cases would benefit if we have THPs for CMAs.

Could we add the support for MIGRATE_CMA pages on the PCP and THP lists?

Thanks