[v2,0/2] Fix subsection vmemmap_populate logic

Message

Zhenhua Huang Dec. 9, 2024, 9:42 a.m. UTC

To perform memory hotplug operations, the memmap (aka struct page) will be
updated. For arm64 with 4K page size, the typical granularity is 128M,
which corresponds to a 2M memmap buffer.
Commit c1cc1552616d ("arm64: MMU initialisation")
optimizes this 2M buffer to be mapped with one single PMD entry. However,
commit ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug")
which supports 2M subsection hotplug granularity, causes other issues
(refer to the change log of patch #1). The logic is adjusted to populate
with huge pages only if the hotplug address/size is section-aligned.

Changes since v1:
  - Modified change log to make it more clear which was based on Catalin's
    comments.

Zhenhua Huang (2):
  arm64: mm: vmemmap populate to page level if not section aligned
  arm64: mm: implement vmemmap_check_pmd for arm64

 arch/arm64/mm/mmu.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)