[RFC V2 0/2] arm64/mm: Enable THP migration

[Anshuman Khandual]

This series enables THP migration on arm64 via ARCH_ENABLE_THP_MIGRATION.
But first this modifies all existing THP helpers like pmd_present() and
pmd_trans_huge() etc per expected generic memory semantics as concluded
from a previous discussion here.

https://lkml.org/lkml/2018/10/9/220

This series is based on v5.8-rc1.

Changes in RFC V2:

- Used PMD_TABLE_BIT to represent splitting PMD state per Catalin

Changes in RFC V1: (https://patchwork.kernel.org/project/linux-mm/list/?series=138797)

Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Suzuki Poulose <suzuki.poulose@xxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

Anshuman Khandual (2):
  arm64/mm: Change THP helpers per generic memory semantics
  arm64/mm: Enable THP migration

 arch/arm64/Kconfig               |   4 ++
 arch/arm64/include/asm/pgtable.h | 102 +++++++++++++++++++++++++++----
 arch/arm64/mm/hugetlbpage.c      |   2 +-
 arch/arm64/mm/mmu.c              |  20 ++++++
 4 files changed, 116 insertions(+), 12 deletions(-)

-- 
2.20.1