[RFC PATCH v2 00/11] HugeTLB and THP support for ARM64.

[Steve Capper <steve.capper@linaro.org>]

This series brings huge pages and transparent huge pages to ARM64.
The functionality is very similar to x86, and a lot of code that can
be used by both ARM64 and x86 is brought into mm to avoid the need
for code duplication.

One notable difference from x86 is that ARM64 supports normal pages
that are 64KB. When 64KB pages are enabled, huge page and
transparent huge pages are 512MB only, otherwise the sizes match
x86.

This series applies to 3.9, and requires one additional patch
ARM64: mm: Correct show_pte behaviour
http://lists.infradead.org/pipermail/linux-arm-kernel/2013-April/164157.html

I've tested this under the ARMv8 models (Fast and Foundation) and
the x86 code has been tested in a KVM guest. libhugetlbfs was used
for testing under both architectures.

The most significant changes since the first RFC are:

   * PROT_NONE support added for HugeTLB and THP.
   * pmd_modify implementation fixed.
   * Superfluous huge dcache flushing code removed.
   * Simplified (and corrected) MAX_ORDER raise for THP && 64KB
     pages.
   * The MAX_ORDER check in huge_mm.h has been corrected.

I would be particularly interested in any feedback regarding the
first 4 patches in the series (the promotion of some huge page
code from x86 to mm), as this would also allow me to simplify
my patches for huge page support in ARM.

--

Steve Capper (11):
  mm: hugetlb: Copy huge_pmd_share from x86 to mm.
  x86: mm: Remove x86 version of huge_pmd_share.
  mm: hugetlb: Copy general hugetlb code from x86 to mm.
  x86: mm: Remove general hugetlb code from x86.
  mm: thp: Correct the HPAGE_PMD_ORDER check.
  ARM64: mm: Restore memblock limit when map_mem finished.
  ARM64: mm: Make PAGE_NONE pages read only and no-execute.
  ARM64: mm: Swap PTE_FILE and PTE_PROT_NONE bits.
  ARM64: mm: HugeTLB support.
  ARM64: mm: Raise MAX_ORDER for 64KB pages and THP.
  ARM64: mm: THP support.

 arch/arm64/Kconfig                     |  17 +++
 arch/arm64/include/asm/hugetlb.h       | 121 ++++++++++++++++++
 arch/arm64/include/asm/pgtable-hwdef.h |  12 ++
 arch/arm64/include/asm/pgtable.h       |  80 ++++++++++--
 arch/arm64/include/asm/tlb.h           |   6 +
 arch/arm64/include/asm/tlbflush.h      |   2 +
 arch/arm64/mm/Makefile                 |   1 +
 arch/arm64/mm/fault.c                  |  19 +--
 arch/arm64/mm/hugetlbpage.c            |  70 +++++++++++
 arch/arm64/mm/mmu.c                    |  19 ++-
 arch/x86/Kconfig                       |   6 +
 arch/x86/mm/hugetlbpage.c              | 187 ----------------------------
 include/linux/huge_mm.h                |   2 +-
 include/linux/hugetlb.h                |   4 +
 mm/hugetlb.c                           | 219 +++++++++++++++++++++++++++++++--
 15 files changed, 539 insertions(+), 226 deletions(-)
 create mode 100644 arch/arm64/include/asm/hugetlb.h
 create mode 100644 arch/arm64/mm/hugetlbpage.c

-- 
1.8.1.4

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