diff options
| -rw-r--r-- | mm/hugetlb.c | 37 | ||||
| -rw-r--r-- | mm/internal.h | 28 |
2 files changed, 64 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 421aee99b84a..e6afe527bd09 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -354,11 +354,26 @@ static int vma_has_reserves(struct vm_area_struct *vma) return 0; } +static void clear_gigantic_page(struct page *page, + unsigned long addr, unsigned long sz) +{ + int i; + struct page *p = page; + + might_sleep(); + for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) { + cond_resched(); + clear_user_highpage(p, addr + i * PAGE_SIZE); + } +} static void clear_huge_page(struct page *page, unsigned long addr, unsigned long sz) { int i; + if (unlikely(sz > MAX_ORDER_NR_PAGES)) + return clear_gigantic_page(page, addr, sz); + might_sleep(); for (i = 0; i < sz/PAGE_SIZE; i++) { cond_resched(); @@ -366,12 +381,32 @@ static void clear_huge_page(struct page *page, } } +static void copy_gigantic_page(struct page *dst, struct page *src, + unsigned long addr, struct vm_area_struct *vma) +{ + int i; + struct hstate *h = hstate_vma(vma); + struct page *dst_base = dst; + struct page *src_base = src; + might_sleep(); + for (i = 0; i < pages_per_huge_page(h); ) { + cond_resched(); + copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma); + + i++; + dst = mem_map_next(dst, dst_base, i); + src = mem_map_next(src, src_base, i); + } +} static void copy_huge_page(struct page *dst, struct page *src, unsigned long addr, struct vm_area_struct *vma) { int i; struct hstate *h = hstate_vma(vma); + if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) + return copy_gigantic_page(dst, src, addr, vma); + might_sleep(); for (i = 0; i < pages_per_huge_page(h); i++) { cond_resched(); @@ -2130,7 +2165,7 @@ same_page: if (zeropage_ok) pages[i] = ZERO_PAGE(0); else - pages[i] = page + pfn_offset; + pages[i] = mem_map_offset(page, pfn_offset); get_page(pages[i]); } diff --git a/mm/internal.h b/mm/internal.h index e4e728bdf324..f482460de3e6 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -176,6 +176,34 @@ static inline void free_page_mlock(struct page *page) { } #endif /* CONFIG_UNEVICTABLE_LRU */ /* + * Return the mem_map entry representing the 'offset' subpage within + * the maximally aligned gigantic page 'base'. Handle any discontiguity + * in the mem_map at MAX_ORDER_NR_PAGES boundaries. + */ +static inline struct page *mem_map_offset(struct page *base, int offset) +{ + if (unlikely(offset >= MAX_ORDER_NR_PAGES)) + return pfn_to_page(page_to_pfn(base) + offset); + return base + offset; +} + +/* + * Iterator over all subpages withing the maximally aligned gigantic + * page 'base'. Handle any discontiguity in the mem_map. + */ +static inline struct page *mem_map_next(struct page *iter, + struct page *base, int offset) +{ + if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { + unsigned long pfn = page_to_pfn(base) + offset; + if (!pfn_valid(pfn)) + return NULL; + return pfn_to_page(pfn); + } + return iter + 1; +} + +/* * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, * so all functions starting at paging_init should be marked __init * in those cases. SPARSEMEM, however, allows for memory hotplug, |