On Mon, 22 May 2017 17:25:55 +0100
Punit Agrawal <punit.agrawal@xxxxxxx> wrote:
> When unmapping a hugepage range, huge_pte_clear() is used to clear the
> page table entries that are marked as not present. huge_pte_clear()
> internally just ends up calling pte_clear() which does not correctly
> deal with hugepages consisting of contiguous page table entries.
>
> Add a size argument to address this issue and allow architectures to
> override huge_pte_clear() by wrapping it in a #ifndef block.
>
> Update s390 implementation with the size parameter as well.
>
> Note that the change only affects huge_pte_clear() - the other generic
> hugetlb functions don't need any change.
>
> Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx>
> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> ---
>
> Changes since v3
>
> * Drop weak function and use #ifndef block to allow architecture override
> * Drop unnecessary move of s390 function definition
>
> arch/s390/include/asm/hugetlb.h | 2 +-
> include/asm-generic/hugetlb.h | 4 +++-
> mm/hugetlb.c | 2 +-
> 3 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
> index cd546a245c68..c0443500baec 100644
> --- a/arch/s390/include/asm/hugetlb.h
> +++ b/arch/s390/include/asm/hugetlb.h
> @@ -39,7 +39,7 @@ static inline int prepare_hugepage_range(struct file *file,
> #define arch_clear_hugepage_flags(page) do { } while (0)
>
> static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep)
> + pte_t *ptep, unsigned long sz)
> {
> if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
> pte_val(*ptep) = _REGION3_ENTRY_EMPTY;
For the nop-change for s390:
Acked-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.
