On Thu, 28 Aug 2014, Naoya Horiguchi wrote:
> follow_huge_addr()'s parameter write is not used, so let's remove it.
>
> Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
I think this patch is a waste of time: that it should be replaced
by a patch which replaces the "write" argument by a "flags" argument,
so that follow_huge_addr() can do get_page() for FOLL_GET while holding
appropriate lock, instead of the BUG_ON(flags & FOLL_GET) we currently
have.
Once that is implemented, you could try getting hugetlb migration
tested on ia64 and powerpc; but yes, keep hugetlb migration disabled
on all but x86 until it has been tested elsewhere.
> ---
> arch/ia64/mm/hugetlbpage.c | 2 +-
> arch/powerpc/mm/hugetlbpage.c | 2 +-
> arch/x86/mm/hugetlbpage.c | 2 +-
> include/linux/hugetlb.h | 5 ++---
> mm/gup.c | 2 +-
> mm/hugetlb.c | 3 +--
> 6 files changed, 7 insertions(+), 9 deletions(-)
>
> diff --git mmotm-2014-08-25-16-52.orig/arch/ia64/mm/hugetlbpage.c mmotm-2014-08-25-16-52/arch/ia64/mm/hugetlbpage.c
> index 6170381bf074..524a4e001bda 100644
> --- mmotm-2014-08-25-16-52.orig/arch/ia64/mm/hugetlbpage.c
> +++ mmotm-2014-08-25-16-52/arch/ia64/mm/hugetlbpage.c
> @@ -89,7 +89,7 @@ int prepare_hugepage_range(struct file *file,
> return 0;
> }
>
> -struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
> +struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr)
> {
> struct page *page = NULL;
> pte_t *ptep;
> diff --git mmotm-2014-08-25-16-52.orig/arch/powerpc/mm/hugetlbpage.c mmotm-2014-08-25-16-52/arch/powerpc/mm/hugetlbpage.c
> index 1d8854a56309..5b6fe8b0cde3 100644
> --- mmotm-2014-08-25-16-52.orig/arch/powerpc/mm/hugetlbpage.c
> +++ mmotm-2014-08-25-16-52/arch/powerpc/mm/hugetlbpage.c
> @@ -674,7 +674,7 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
> }
>
> struct page *
> -follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
> +follow_huge_addr(struct mm_struct *mm, unsigned long address)
> {
> pte_t *ptep;
> struct page *page = ERR_PTR(-EINVAL);
> diff --git mmotm-2014-08-25-16-52.orig/arch/x86/mm/hugetlbpage.c mmotm-2014-08-25-16-52/arch/x86/mm/hugetlbpage.c
> index 03b8a7c11817..cab09d87ae65 100644
> --- mmotm-2014-08-25-16-52.orig/arch/x86/mm/hugetlbpage.c
> +++ mmotm-2014-08-25-16-52/arch/x86/mm/hugetlbpage.c
> @@ -18,7 +18,7 @@
>
> #if 0 /* This is just for testing */
> struct page *
> -follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
> +follow_huge_addr(struct mm_struct *mm, unsigned long address)
> {
> unsigned long start = address;
> int length = 1;
> diff --git mmotm-2014-08-25-16-52.orig/include/linux/hugetlb.h mmotm-2014-08-25-16-52/include/linux/hugetlb.h
> index b3200fce07aa..cdff1bd393bb 100644
> --- mmotm-2014-08-25-16-52.orig/include/linux/hugetlb.h
> +++ mmotm-2014-08-25-16-52/include/linux/hugetlb.h
> @@ -96,8 +96,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
> unsigned long addr, unsigned long sz);
> pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr);
> int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep);
> -struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
> - int write);
> +struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address);
> struct page *follow_huge_pmd(struct vm_area_struct *vma, unsigned long address,
> pmd_t *pmd, int flags);
> struct page *follow_huge_pud(struct vm_area_struct *vma, unsigned long address,
> @@ -124,7 +123,7 @@ static inline unsigned long hugetlb_total_pages(void)
> }
>
> #define follow_hugetlb_page(m,v,p,vs,a,b,i,w) ({ BUG(); 0; })
> -#define follow_huge_addr(mm, addr, write) ERR_PTR(-EINVAL)
> +#define follow_huge_addr(mm, addr) ERR_PTR(-EINVAL)
> #define copy_hugetlb_page_range(src, dst, vma) ({ BUG(); 0; })
> static inline void hugetlb_report_meminfo(struct seq_file *m)
> {
> diff --git mmotm-2014-08-25-16-52.orig/mm/gup.c mmotm-2014-08-25-16-52/mm/gup.c
> index 597a5e92e265..8f0550f1770d 100644
> --- mmotm-2014-08-25-16-52.orig/mm/gup.c
> +++ mmotm-2014-08-25-16-52/mm/gup.c
> @@ -149,7 +149,7 @@ struct page *follow_page_mask(struct vm_area_struct *vma,
>
> *page_mask = 0;
>
> - page = follow_huge_addr(mm, address, flags & FOLL_WRITE);
> + page = follow_huge_addr(mm, address);
> if (!IS_ERR(page)) {
> BUG_ON(flags & FOLL_GET);
> return page;
> diff --git mmotm-2014-08-25-16-52.orig/mm/hugetlb.c mmotm-2014-08-25-16-52/mm/hugetlb.c
> index 0a4511115ee0..f7dcad3474ec 100644
> --- mmotm-2014-08-25-16-52.orig/mm/hugetlb.c
> +++ mmotm-2014-08-25-16-52/mm/hugetlb.c
> @@ -3690,8 +3690,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
> * behavior.
> */
> struct page * __weak
> -follow_huge_addr(struct mm_struct *mm, unsigned long address,
> - int write)
> +follow_huge_addr(struct mm_struct *mm, unsigned long address)
> {
> return ERR_PTR(-EINVAL);
> }
> --
> 1.9.3
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