Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
powerpc/book3s64/memhotplug: enable memmap on memory for radix
Radix vmemmap mapping can map things correctly at the PMD level or PTE level based on different device boundary checks. Hence we skip the restrictions w.r.t vmemmap size to be multiple of PMD_SIZE. This also makes the feature widely useful because to use PMD_SIZE vmemmap area we require a memory block size of 2GiB We can also use MHP_RESERVE_PAGES_MEMMAP_ON_MEMORY to that the feature can work with a memory block size of 256MB. Using altmap.reserve feature to align things correctly at pageblock granularity. We can end up losing some pages in memory with this. For ex: with a 256MiB memory block size, we require 4 pages to map vmemmap pages, In order to align things correctly we end up adding a reserve of 28 pages. ie, for every 4096 pages 28 pages get reserved. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Aneesh Kumar K.V <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Cc: Christophe Leroy <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Vishal Verma <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
- Loading branch information