[PATCH v4 0/2] arm64/hugetlb: enable gigantic page

[Yisheng Xie]

changelog
=========
v3->v4:
add changelog in the cover leter to make the change history more clear.

v2->v3:
change the Kconfig file to avoid comile warning when select
ARCH_HAS_GIGANTIC_PAGE with !CONFIG_HUGETLB_PAGE

v1->v2:
introduce the ARCH_HAS_GIGANTIC_PAGE as Michal Hocko <mhocko@xxxxxxxx> suggested

Arm64 supports different size of gigantic page which can be seen from:
commit 084bd29810a5 ("ARM64: mm: HugeTLB support.")
commit 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")

So I tried to use this function by adding hugepagesz=1G in kernel
parameters, with CONFIG_CMA=y. However, when I
echo xx > \
  /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
it failed with the following info:
-bash: echo: write error: Invalid argument

This is a v4 patchset which make gigantic page can be
allocated and freed at runtime for arch arm64,
with CONFIG_CMA=y or other related configs is enabled.

You can see the former discussions at:
https://lkml.org/lkml/2016/8/18/310
https://lkml.org/lkml/2016/8/21/410
https://lkml.org/lkml/2016/8/22/319

Yisheng Xie (2):
  mm/hugetlb: Introduce ARCH_HAS_GIGANTIC_PAGE
  arm64 Kconfig: Select gigantic page

 arch/arm64/Kconfig | 1 +
 arch/s390/Kconfig  | 1 +
 arch/x86/Kconfig   | 1 +
 fs/Kconfig         | 3 +++
 mm/hugetlb.c       | 2 +-
 5 files changed, 7 insertions(+), 1 deletion(-)

-- 
1.7.12.4