mincore: apply page table walker on do_mincore()
This patch makes do_mincore() use walk_page_vma(), which reduces many
lines of code by using common page table walk code.
[daeseok.youn@gmail.com: remove unneeded variable 'err']
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mincore.c b/mm/mincore.c
index 46527c0..be25efd 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -19,38 +19,25 @@
#include <asm/uaccess.h>
#include <asm/pgtable.h>
-static void mincore_hugetlb_page_range(struct vm_area_struct *vma,
- unsigned long addr, unsigned long end,
- unsigned char *vec)
+static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr,
+ unsigned long end, struct mm_walk *walk)
{
#ifdef CONFIG_HUGETLB_PAGE
- struct hstate *h;
+ unsigned char present;
+ unsigned char *vec = walk->private;
- h = hstate_vma(vma);
- while (1) {
- unsigned char present;
- pte_t *ptep;
- /*
- * Huge pages are always in RAM for now, but
- * theoretically it needs to be checked.
- */
- ptep = huge_pte_offset(current->mm,
- addr & huge_page_mask(h));
- present = ptep && !huge_pte_none(huge_ptep_get(ptep));
- while (1) {
- *vec = present;
- vec++;
- addr += PAGE_SIZE;
- if (addr == end)
- return;
- /* check hugepage border */
- if (!(addr & ~huge_page_mask(h)))
- break;
- }
- }
+ /*
+ * Hugepages under user process are always in RAM and never
+ * swapped out, but theoretically it needs to be checked.
+ */
+ present = pte && !huge_pte_none(huge_ptep_get(pte));
+ for (; addr != end; vec++, addr += PAGE_SIZE)
+ *vec = present;
+ walk->private = vec;
#else
BUG();
#endif
+ return 0;
}
/*
@@ -94,9 +81,8 @@
return present;
}
-static void mincore_unmapped_range(struct vm_area_struct *vma,
- unsigned long addr, unsigned long end,
- unsigned char *vec)
+static int __mincore_unmapped_range(unsigned long addr, unsigned long end,
+ struct vm_area_struct *vma, unsigned char *vec)
{
unsigned long nr = (end - addr) >> PAGE_SHIFT;
int i;
@@ -111,23 +97,44 @@
for (i = 0; i < nr; i++)
vec[i] = 0;
}
+ return nr;
}
-static void mincore_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
- unsigned long addr, unsigned long end,
- unsigned char *vec)
+static int mincore_unmapped_range(unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
{
- unsigned long next;
- spinlock_t *ptl;
- pte_t *ptep;
+ walk->private += __mincore_unmapped_range(addr, end,
+ walk->vma, walk->private);
+ return 0;
+}
- ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
- do {
+static int mincore_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ spinlock_t *ptl;
+ struct vm_area_struct *vma = walk->vma;
+ pte_t *ptep;
+ unsigned char *vec = walk->private;
+ int nr = (end - addr) >> PAGE_SHIFT;
+
+ if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
+ memset(vec, 1, nr);
+ spin_unlock(ptl);
+ goto out;
+ }
+
+ if (pmd_trans_unstable(pmd)) {
+ __mincore_unmapped_range(addr, end, vma, vec);
+ goto out;
+ }
+
+ ptep = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
+ for (; addr != end; ptep++, addr += PAGE_SIZE) {
pte_t pte = *ptep;
- next = addr + PAGE_SIZE;
if (pte_none(pte))
- mincore_unmapped_range(vma, addr, next, vec);
+ __mincore_unmapped_range(addr, addr + PAGE_SIZE,
+ vma, vec);
else if (pte_present(pte))
*vec = 1;
else { /* pte is a swap entry */
@@ -150,69 +157,12 @@
}
}
vec++;
- } while (ptep++, addr = next, addr != end);
+ }
pte_unmap_unlock(ptep - 1, ptl);
-}
-
-static void mincore_pmd_range(struct vm_area_struct *vma, pud_t *pud,
- unsigned long addr, unsigned long end,
- unsigned char *vec)
-{
- unsigned long next;
- pmd_t *pmd;
-
- pmd = pmd_offset(pud, addr);
- do {
- next = pmd_addr_end(addr, end);
- if (pmd_trans_huge(*pmd)) {
- if (mincore_huge_pmd(vma, pmd, addr, next, vec)) {
- vec += (next - addr) >> PAGE_SHIFT;
- continue;
- }
- /* fall through */
- }
- if (pmd_none_or_trans_huge_or_clear_bad(pmd))
- mincore_unmapped_range(vma, addr, next, vec);
- else
- mincore_pte_range(vma, pmd, addr, next, vec);
- vec += (next - addr) >> PAGE_SHIFT;
- } while (pmd++, addr = next, addr != end);
-}
-
-static void mincore_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
- unsigned long addr, unsigned long end,
- unsigned char *vec)
-{
- unsigned long next;
- pud_t *pud;
-
- pud = pud_offset(pgd, addr);
- do {
- next = pud_addr_end(addr, end);
- if (pud_none_or_clear_bad(pud))
- mincore_unmapped_range(vma, addr, next, vec);
- else
- mincore_pmd_range(vma, pud, addr, next, vec);
- vec += (next - addr) >> PAGE_SHIFT;
- } while (pud++, addr = next, addr != end);
-}
-
-static void mincore_page_range(struct vm_area_struct *vma,
- unsigned long addr, unsigned long end,
- unsigned char *vec)
-{
- unsigned long next;
- pgd_t *pgd;
-
- pgd = pgd_offset(vma->vm_mm, addr);
- do {
- next = pgd_addr_end(addr, end);
- if (pgd_none_or_clear_bad(pgd))
- mincore_unmapped_range(vma, addr, next, vec);
- else
- mincore_pud_range(vma, pgd, addr, next, vec);
- vec += (next - addr) >> PAGE_SHIFT;
- } while (pgd++, addr = next, addr != end);
+out:
+ walk->private += nr;
+ cond_resched();
+ return 0;
}
/*
@@ -224,18 +174,22 @@
{
struct vm_area_struct *vma;
unsigned long end;
+ int err;
+ struct mm_walk mincore_walk = {
+ .pmd_entry = mincore_pte_range,
+ .pte_hole = mincore_unmapped_range,
+ .hugetlb_entry = mincore_hugetlb,
+ .private = vec,
+ };
vma = find_vma(current->mm, addr);
if (!vma || addr < vma->vm_start)
return -ENOMEM;
-
+ mincore_walk.mm = vma->vm_mm;
end = min(vma->vm_end, addr + (pages << PAGE_SHIFT));
-
- if (is_vm_hugetlb_page(vma))
- mincore_hugetlb_page_range(vma, addr, end, vec);
- else
- mincore_page_range(vma, addr, end, vec);
-
+ err = walk_page_range(addr, end, &mincore_walk);
+ if (err < 0)
+ return err;
return (end - addr) >> PAGE_SHIFT;
}