diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index d47a7c41745d09b4b835b114b099e3beb65eb407..e688fd89354d1ee38e640204f47b893268cc0d8d 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -99,6 +99,7 @@ static inline void hugetlb_report_meminfo(struct seq_file *m)
#define is_hugepage_only_range(mm, addr, len) 0
#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; })
#define hugetlb_fault(mm, vma, addr, flags) ({ BUG(); 0; })
+#define huge_pte_offset(mm, address) 0
#define hugetlb_change_protection(vma, address, end, newprot)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index b2bd2bae97755ccf800f66e82a2e4d65d7525f3f..a547d96891705bce59b0973123e172877bdbe890 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -282,10 +282,16 @@ static inline loff_t page_offset(struct page *page)
return ((loff_t)page->index) << PAGE_CACHE_SHIFT;
}
+extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
+ unsigned long address);
+
static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
unsigned long address)
{
- pgoff_t pgoff = (address - vma->vm_start) >> PAGE_SHIFT;
+ pgoff_t pgoff;
+ if (unlikely(is_vm_hugetlb_page(vma)))
+ return linear_hugepage_index(vma, address);
+ pgoff = (address - vma->vm_start) >> PAGE_SHIFT;
pgoff += vma->vm_pgoff;
return pgoff >> (PAGE_CACHE_SHIFT - PAGE_SHIFT);
}
diff --git a/include/linux/poison.h b/include/linux/poison.h
index 34066ffd893d733b8134da1b57915bec314afb48..2110a81c5e2afaab47ec5cb107cf17503d731317 100644
--- a/include/linux/poison.h
+++ b/include/linux/poison.h
@@ -48,15 +48,6 @@
#define POISON_FREE 0x6b /* for use-after-free poisoning */
#define POISON_END 0xa5 /* end-byte of poisoning */
-/********** mm/hugetlb.c **********/
-/*
- * Private mappings of hugetlb pages use this poisoned value for
- * page->mapping. The core VM should not be doing anything with this mapping
- * but futex requires the existence of some page->mapping value even though it
- * is unused if PAGE_MAPPING_ANON is set.
- */
-#define HUGETLB_POISON ((void *)(0x00300300 + POISON_POINTER_DELTA + PAGE_MAPPING_ANON))
-
/********** arch/$ARCH/mm/init.c **********/
#define POISON_FREE_INITMEM 0xcc
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 77216742c178013b9444884b4f4dd05d337a4620..9d50e7ef5f5a7ff729e99eff011135221f55b301 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -140,6 +140,11 @@ void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned lon
void page_add_file_rmap(struct page *);
void page_remove_rmap(struct page *);
+void hugepage_add_anon_rmap(struct page *, struct vm_area_struct *,
+ unsigned long);
+void hugepage_add_new_anon_rmap(struct page *, struct vm_area_struct *,
+ unsigned long);
+
static inline void page_dup_rmap(struct page *page)
{
atomic_inc(&page->_mapcount);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 54d42b009dbeb5feb15c2fb08ac09239e0bf9feb..aa3c517393782af5cd8741add7f88bf07c500ef1 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -18,6 +18,7 @@
#include <linux/bootmem.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
+#include <linux/rmap.h>
#include <asm/page.h>
#include <asm/pgtable.h>
@@ -220,6 +221,12 @@ static pgoff_t vma_hugecache_offset(struct hstate *h,
(vma->vm_pgoff >> huge_page_order(h));
}
+pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
+ unsigned long address)
+{
+ return vma_hugecache_offset(hstate_vma(vma), vma, address);
+}
+
/*
* Return the size of the pages allocated when backing a VMA. In the majority
* cases this will be same size as used by the page table entries.
@@ -552,6 +559,7 @@ static void free_huge_page(struct page *page)
set_page_private(page, 0);
page->mapping = NULL;
BUG_ON(page_count(page));
+ BUG_ON(page_mapcount(page));
INIT_LIST_HEAD(&page->lru);
spin_lock(&hugetlb_lock);
@@ -2129,6 +2137,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
entry = huge_ptep_get(src_pte);
ptepage = pte_page(entry);
get_page(ptepage);
+ page_dup_rmap(ptepage);
set_huge_pte_at(dst, addr, dst_pte, entry);
}
spin_unlock(&src->page_table_lock);
@@ -2207,6 +2216,7 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
flush_tlb_range(vma, start, end);
mmu_notifier_invalidate_range_end(mm, start, end);
list_for_each_entry_safe(page, tmp, &page_list, lru) {
+ page_remove_rmap(page);
list_del(&page->lru);
put_page(page);
}
@@ -2272,6 +2282,9 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
return 1;
}
+/*
+ * Hugetlb_cow() should be called with page lock of the original hugepage held.
+ */
static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *ptep, pte_t pte,
struct page *pagecache_page)
@@ -2286,8 +2299,11 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
retry_avoidcopy:
/* If no-one else is actually using this page, avoid the copy
* and just make the page writable */
- avoidcopy = (page_count(old_page) == 1);
+ avoidcopy = (page_mapcount(old_page) == 1);
if (avoidcopy) {
+ if (!trylock_page(old_page))
+ if (PageAnon(old_page))
+ page_move_anon_rmap(old_page, vma, address);
set_huge_ptep_writable(vma, address, ptep);
return 0;
}
@@ -2338,6 +2354,13 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
return -PTR_ERR(new_page);
}
+ /*
+ * When the original hugepage is shared one, it does not have
+ * anon_vma prepared.
+ */
+ if (unlikely(anon_vma_prepare(vma)))
+ return VM_FAULT_OOM;
+
copy_huge_page(new_page, old_page, address, vma);
__SetPageUptodate(new_page);
@@ -2352,6 +2375,8 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
huge_ptep_clear_flush(vma, address, ptep);
set_huge_pte_at(mm, address, ptep,
make_huge_pte(vma, new_page, 1));
+ page_remove_rmap(old_page);
+ hugepage_add_anon_rmap(new_page, vma, address);
/* Make the old page be freed below */
new_page = old_page;
}
@@ -2452,10 +2477,17 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
spin_lock(&inode->i_lock);
inode->i_blocks += blocks_per_huge_page(h);
spin_unlock(&inode->i_lock);
+ page_dup_rmap(page);
} else {
lock_page(page);
- page->mapping = HUGETLB_POISON;
+ if (unlikely(anon_vma_prepare(vma))) {
+ ret = VM_FAULT_OOM;
+ goto backout_unlocked;
+ }
+ hugepage_add_new_anon_rmap(page, vma, address);
}
+ } else {
+ page_dup_rmap(page);
}
/*
@@ -2507,6 +2539,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
pte_t *ptep;
pte_t entry;
int ret;
+ struct page *page = NULL;
struct page *pagecache_page = NULL;
static DEFINE_MUTEX(hugetlb_instantiation_mutex);
struct hstate *h = hstate_vma(vma);
@@ -2548,6 +2581,11 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
vma, address);
}
+ if (!pagecache_page) {
+ page = pte_page(entry);
+ lock_page(page);
+ }
+
spin_lock(&mm->page_table_lock);
/* Check for a racing update before calling hugetlb_cow */
if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
@@ -2573,6 +2611,8 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
if (pagecache_page) {
unlock_page(pagecache_page);
put_page(pagecache_page);
+ } else {
+ unlock_page(page);
}
out_mutex:
diff --git a/mm/rmap.c b/mm/rmap.c
index 38a336e2eea1e104a654052834ef93e252340d18..0ad53572eaf24d5e78483378cbcf6f723c154065 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -56,6 +56,7 @@
#include <linux/memcontrol.h>
#include <linux/mmu_notifier.h>
#include <linux/migrate.h>
+#include <linux/hugetlb.h>
#include <asm/tlbflush.h>
@@ -326,6 +327,8 @@ vma_address(struct page *page, struct vm_area_struct *vma)
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
unsigned long address;
+ if (unlikely(is_vm_hugetlb_page(vma)))
+ pgoff = page->index << huge_page_order(page_hstate(page));
address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
if (unlikely(address < vma->vm_start || address >= vma->vm_end)) {
/* page should be within @vma mapping range */
@@ -369,6 +372,12 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm,
pte_t *pte;
spinlock_t *ptl;
+ if (unlikely(PageHuge(page))) {
+ pte = huge_pte_offset(mm, address);
+ ptl = &mm->page_table_lock;
+ goto check;
+ }
+
pgd = pgd_offset(mm, address);
if (!pgd_present(*pgd))
return NULL;
@@ -389,6 +398,7 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm,
}
ptl = pte_lockptr(mm, pmd);
+check:
spin_lock(ptl);
if (pte_present(*pte) && page_to_pfn(page) == pte_pfn(*pte)) {
*ptlp = ptl;
@@ -873,6 +883,12 @@ void page_remove_rmap(struct page *page)
page_clear_dirty(page);
set_page_dirty(page);
}
+ /*
+ * Hugepages are not counted in NR_ANON_PAGES nor NR_FILE_MAPPED
+ * and not charged by memcg for now.
+ */
+ if (unlikely(PageHuge(page)))
+ return;
if (PageAnon(page)) {
mem_cgroup_uncharge_page(page);
__dec_zone_page_state(page, NR_ANON_PAGES);
@@ -1445,3 +1461,46 @@ int rmap_walk(struct page *page, int (*rmap_one)(struct page *,
return rmap_walk_file(page, rmap_one, arg);
}
#endif /* CONFIG_MIGRATION */
+
+#ifdef CONFIG_HUGETLBFS
+/*
+ * The following three functions are for anonymous (private mapped) hugepages.
+ * Unlike common anonymous pages, anonymous hugepages have no accounting code
+ * and no lru code, because we handle hugepages differently from common pages.
+ */
+static void __hugepage_set_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address, int exclusive)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+ BUG_ON(!anon_vma);
+ if (!exclusive) {
+ struct anon_vma_chain *avc;
+ avc = list_entry(vma->anon_vma_chain.prev,
+ struct anon_vma_chain, same_vma);
+ anon_vma = avc->anon_vma;
+ }
+ anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
+ page->mapping = (struct address_space *) anon_vma;
+ page->index = linear_page_index(vma, address);
+}
+
+void hugepage_add_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+ int first;
+ BUG_ON(!anon_vma);
+ BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+ first = atomic_inc_and_test(&page->_mapcount);
+ if (first)
+ __hugepage_set_anon_rmap(page, vma, address, 0);
+}
+
+void hugepage_add_new_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+ atomic_set(&page->_mapcount, 0);
+ __hugepage_set_anon_rmap(page, vma, address, 1);
+}
+#endif /* CONFIG_HUGETLBFS */