diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/hugetlb.c | 177 |
1 files changed, 176 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 4eb5ae3fbe1..fbd1111ea11 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -7,10 +7,14 @@ #include <linux/init.h> #include <linux/module.h> #include <linux/mm.h> -#include <linux/hugetlb.h> #include <linux/sysctl.h> #include <linux/highmem.h> #include <linux/nodemask.h> +#include <linux/pagemap.h> +#include <asm/page.h> +#include <asm/pgtable.h> + +#include <linux/hugetlb.h> const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; static unsigned long nr_huge_pages, free_huge_pages; @@ -249,6 +253,72 @@ struct vm_operations_struct hugetlb_vm_ops = { .nopage = hugetlb_nopage, }; +static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page) +{ + pte_t entry; + + if (vma->vm_flags & VM_WRITE) { + entry = + pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); + } else { + entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); + } + entry = pte_mkyoung(entry); + entry = pte_mkhuge(entry); + + return entry; +} + +int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, + struct vm_area_struct *vma) +{ + pte_t *src_pte, *dst_pte, entry; + struct page *ptepage; + unsigned long addr = vma->vm_start; + unsigned long end = vma->vm_end; + + while (addr < end) { + dst_pte = huge_pte_alloc(dst, addr); + if (!dst_pte) + goto nomem; + src_pte = huge_pte_offset(src, addr); + BUG_ON(!src_pte || pte_none(*src_pte)); /* prefaulted */ + entry = *src_pte; + ptepage = pte_page(entry); + get_page(ptepage); + add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE); + set_huge_pte_at(dst, addr, dst_pte, entry); + addr += HPAGE_SIZE; + } + return 0; + +nomem: + return -ENOMEM; +} + +void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) +{ + struct mm_struct *mm = vma->vm_mm; + unsigned long address; + pte_t pte; + struct page *page; + + WARN_ON(!is_vm_hugetlb_page(vma)); + BUG_ON(start & ~HPAGE_MASK); + BUG_ON(end & ~HPAGE_MASK); + + for (address = start; address < end; address += HPAGE_SIZE) { + pte = huge_ptep_get_and_clear(mm, address, huge_pte_offset(mm, address)); + if (pte_none(pte)) + continue; + page = pte_page(pte); + put_page(page); + } + add_mm_counter(mm, rss, -((end - start) >> PAGE_SHIFT)); + flush_tlb_range(vma, start, end); +} + void zap_hugepage_range(struct vm_area_struct *vma, unsigned long start, unsigned long length) { @@ -258,3 +328,108 @@ void zap_hugepage_range(struct vm_area_struct *vma, unmap_hugepage_range(vma, start, start + length); spin_unlock(&mm->page_table_lock); } + +int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma) +{ + struct mm_struct *mm = current->mm; + unsigned long addr; + int ret = 0; + + WARN_ON(!is_vm_hugetlb_page(vma)); + BUG_ON(vma->vm_start & ~HPAGE_MASK); + BUG_ON(vma->vm_end & ~HPAGE_MASK); + + hugetlb_prefault_arch_hook(mm); + + spin_lock(&mm->page_table_lock); + for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { + unsigned long idx; + pte_t *pte = huge_pte_alloc(mm, addr); + struct page *page; + + if (!pte) { + ret = -ENOMEM; + goto out; + } + if (! pte_none(*pte)) + hugetlb_clean_stale_pgtable(pte); + + idx = ((addr - vma->vm_start) >> HPAGE_SHIFT) + + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); + page = find_get_page(mapping, idx); + if (!page) { + /* charge the fs quota first */ + if (hugetlb_get_quota(mapping)) { + ret = -ENOMEM; + goto out; + } + page = alloc_huge_page(); + if (!page) { + hugetlb_put_quota(mapping); + ret = -ENOMEM; + goto out; + } + ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC); + if (! ret) { + unlock_page(page); + } else { + hugetlb_put_quota(mapping); + free_huge_page(page); + goto out; + } + } + add_mm_counter(mm, rss, HPAGE_SIZE / PAGE_SIZE); + set_huge_pte_at(mm, addr, pte, make_huge_pte(vma, page)); + } +out: + spin_unlock(&mm->page_table_lock); + return ret; +} + +int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, + struct page **pages, struct vm_area_struct **vmas, + unsigned long *position, int *length, int i) +{ + unsigned long vpfn, vaddr = *position; + int remainder = *length; + + BUG_ON(!is_vm_hugetlb_page(vma)); + + vpfn = vaddr/PAGE_SIZE; + while (vaddr < vma->vm_end && remainder) { + + if (pages) { + pte_t *pte; + struct page *page; + + /* Some archs (sparc64, sh*) have multiple + * pte_ts to each hugepage. We have to make + * sure we get the first, for the page + * indexing below to work. */ + pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); + + /* hugetlb should be locked, and hence, prefaulted */ + WARN_ON(!pte || pte_none(*pte)); + + page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)]; + + WARN_ON(!PageCompound(page)); + + get_page(page); + pages[i] = page; + } + + if (vmas) + vmas[i] = vma; + + vaddr += PAGE_SIZE; + ++vpfn; + --remainder; + ++i; + } + + *length = remainder; + *position = vaddr; + + return i; +} |