(1) Backgroud
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 PTE
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 bugs
After I tested the libhugetlbfs, I found several bugs in arm64 code.
This patch set has all the bug fixes for the arm64.
(3) The test result in the Softiron and Juno-r1 boards:
This detail test result shows below (both the "make func" & "make stress"):
4KB granule:
1.1) PTE + Contiguous bit : 4K x 16 = 64K (per huge page size)
Test result : PASS
1.2) PMD : 2M x 1 = 2M (per huge page size)
Test result : PASS
1.3) PMD + Contiguous bit : 2M x 16 = 32M (per huge page size)
Test result : PASS
64KB granule:
3.1) PTE + Contiguous bit : 64K x 32 = 2M (per huge page size)
Test result : PASS
3.2) PMD + Contiguous bit : 512M x 32 = 16G (per huge page size)
Test result : no hardware to support this test
Huang Shijie (2):
arm64: hugetlb: remove the wrong pmd check in find_num_contig()
arm64: hugetlb: fix the wrong address for several functions
arch/arm64/mm/hugetlbpage.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
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2.5.5
