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-rw-r--r--fs/proc/task_mmu.c52
1 files changed, 48 insertions, 4 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 3efa7253523..95264c0ef30 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -608,6 +608,9 @@ struct pagemapread {
u64 *buffer;
};
+#define PAGEMAP_WALK_SIZE (PMD_SIZE)
+#define PAGEMAP_WALK_MASK (PMD_MASK)
+
#define PM_ENTRY_BYTES sizeof(u64)
#define PM_STATUS_BITS 3
#define PM_STATUS_OFFSET (64 - PM_STATUS_BITS)
@@ -666,6 +669,27 @@ static u64 pte_to_pagemap_entry(pte_t pte)
return pme;
}
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static u64 thp_pmd_to_pagemap_entry(pmd_t pmd, int offset)
+{
+ u64 pme = 0;
+ /*
+ * Currently pmd for thp is always present because thp can not be
+ * swapped-out, migrated, or HWPOISONed (split in such cases instead.)
+ * This if-check is just to prepare for future implementation.
+ */
+ if (pmd_present(pmd))
+ pme = PM_PFRAME(pmd_pfn(pmd) + offset)
+ | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
+ return pme;
+}
+#else
+static inline u64 thp_pmd_to_pagemap_entry(pmd_t pmd, int offset)
+{
+ return 0;
+}
+#endif
+
static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
@@ -673,15 +697,37 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
struct pagemapread *pm = walk->private;
pte_t *pte;
int err = 0;
+ u64 pfn = PM_NOT_PRESENT;
- split_huge_page_pmd(walk->mm, pmd);
if (pmd_trans_unstable(pmd))
return 0;
/* find the first VMA at or above 'addr' */
vma = find_vma(walk->mm, addr);
+ spin_lock(&walk->mm->page_table_lock);
+ if (pmd_trans_huge(*pmd)) {
+ if (pmd_trans_splitting(*pmd)) {
+ spin_unlock(&walk->mm->page_table_lock);
+ wait_split_huge_page(vma->anon_vma, pmd);
+ } else {
+ for (; addr != end; addr += PAGE_SIZE) {
+ unsigned long offset;
+
+ offset = (addr & ~PAGEMAP_WALK_MASK) >>
+ PAGE_SHIFT;
+ pfn = thp_pmd_to_pagemap_entry(*pmd, offset);
+ err = add_to_pagemap(addr, pfn, pm);
+ if (err)
+ break;
+ }
+ spin_unlock(&walk->mm->page_table_lock);
+ return err;
+ }
+ } else {
+ spin_unlock(&walk->mm->page_table_lock);
+ }
+
for (; addr != end; addr += PAGE_SIZE) {
- u64 pfn = PM_NOT_PRESENT;
/* check to see if we've left 'vma' behind
* and need a new, higher one */
@@ -764,8 +810,6 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
* determine which areas of memory are actually mapped and llseek to
* skip over unmapped regions.
*/
-#define PAGEMAP_WALK_SIZE (PMD_SIZE)
-#define PAGEMAP_WALK_MASK (PMD_MASK)
static ssize_t pagemap_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{