[RFC PATCH 23/31] mm: support 1GB THP pagemap support.

[Zi Yan]

From: Zi Yan <z...@nvidia.com>

Print page flags properly.

Signed-off-by: Zi Yan <z...@nvidia.com>
---
 fs/proc/task_mmu.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f0ec9edab2f3..ccf8ce760283 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1373,6 +1373,45 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long 
addr, unsigned long end,
        return err;
 }
 
+static int pagemap_pud_range(pud_t *pudp, unsigned long addr, unsigned long 
end,
+                            struct mm_walk *walk)
+{
+       struct vm_area_struct *vma = walk->vma;
+       struct pagemapread *pm = walk->private;
+       int err = 0;
+       u64 flags = 0, frame = 0;
+       pud_t pud = *pudp;
+       struct page *page = NULL;
+
+       if (vma->vm_flags & VM_SOFTDIRTY)
+               flags |= PM_SOFT_DIRTY;
+
+       if (pud_present(pud)) {
+               page = pud_page(pud);
+
+               flags |= PM_PRESENT;
+               if (pud_soft_dirty(pud))
+                       flags |= PM_SOFT_DIRTY;
+               if (pm->show_pfn)
+                       frame = pud_pfn(pud) +
+                               ((addr & ~PMD_MASK) >> PAGE_SHIFT);
+       }
+
+       if (page && page_mapcount(page) == 1)
+               flags |= PM_MMAP_EXCLUSIVE;
+
+       for (; addr != end; addr += PAGE_SIZE) {
+               pagemap_entry_t pme = make_pme(frame, flags);
+
+               err = add_to_pagemap(addr, &pme, pm);
+               if (err)
+                       break;
+               if (pm->show_pfn && (flags & PM_PRESENT))
+                       frame++;
+       }
+       return err;
+}
+
 #ifdef CONFIG_HUGETLB_PAGE
 /* This function walks within one hugetlb entry in the single call */
 static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
@@ -1479,6 +1518,9 @@ static ssize_t pagemap_read(struct file *file, char 
__user *buf,
        if (!pm.buffer)
                goto out_mm;
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       pagemap_walk.pud_entry = pagemap_pud_range;
+#endif
        pagemap_walk.pmd_entry = pagemap_pmd_range;
        pagemap_walk.pte_hole = pagemap_pte_hole;
 #ifdef CONFIG_HUGETLB_PAGE
-- 
2.20.1