[PATCH v2 0/6] mm: fix the "counter.sh" failure for libhugetlbfs

On Mon 14-11-16 15:07:33, Huang Shijie wrote:

(1) Background
   For the arm64, the hugetlb page size can be 32M (PMD + Contiguous bit).
   In the 4K page environment, the max page order is 10 (max_order - 1),
   so 32M page is the gigantic page.    

   The arm64 MMU supports a Contiguous bit which is a hint that the TTE
   is one of a set of contiguous entries which can be cached in a single
   TLB entry.  Please refer to the arm64v8 mannul :
       DDI0487A_f_armv8_arm.pdf (in page D4-1811)

(2) The bug   
   After I tested the libhugetlbfs, I found the test case "counter.sh"
   will fail with the gigantic page (32M page in arm64 board).

   This patch set adds support for gigantic surplus hugetlb pages,
   allowing the counter.sh unit test to pass.   

Andrew, I have noticed that this patchset is sitting in the mmotm tree
already. I have to say I am not really happy about the changes it is
introducing. It is making a confused code base even more so. I have
already commented on respective patches but in general I think it needs
a deeper thought before it can be merged.

-- 
Michal Hocko
SUSE Labs