Merge branch 'akpm' (patches from Andrew)

[cascardo/linux.git] / mm / khugepaged.c

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 79c52d0..728d779 100644 (file)
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -838,7 +838,8 @@ static bool hugepage_vma_check(struct vm_area_struct *vma)
  * value (scan code).
  */
 
-static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address)
+static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
+               struct vm_area_struct **vmap)
 {
        struct vm_area_struct *vma;
        unsigned long hstart, hend;
@@ -846,7 +847,7 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address)
        if (unlikely(khugepaged_test_exit(mm)))
                return SCAN_ANY_PROCESS;
 
-       vma = find_vma(mm, address);
+       *vmap = vma = find_vma(mm, address);
        if (!vma)
                return SCAN_VMA_NULL;
 
@@ -881,6 +882,11 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
                .pmd = pmd,
        };
 
+       /* we only decide to swapin, if there is enough young ptes */
+       if (referenced < HPAGE_PMD_NR/2) {
+               trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);
+               return false;
+       }
        fe.pte = pte_offset_map(pmd, address);
        for (; fe.address < address + HPAGE_PMD_NR*PAGE_SIZE;
                        fe.pte++, fe.address += PAGE_SIZE) {
@@ -888,17 +894,12 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
                if (!is_swap_pte(pteval))
                        continue;
                swapped_in++;
-               /* we only decide to swapin, if there is enough young ptes */
-               if (referenced < HPAGE_PMD_NR/2) {
-                       trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);
-                       return false;
-               }
                ret = do_swap_page(&fe, pteval);
 
                /* do_swap_page returns VM_FAULT_RETRY with released mmap_sem */
                if (ret & VM_FAULT_RETRY) {
                        down_read(&mm->mmap_sem);
-                       if (hugepage_vma_revalidate(mm, address)) {
+                       if (hugepage_vma_revalidate(mm, address, &fe.vma)) {
                                /* vma is no longer available, don't continue to swapin */
                                trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);
                                return false;
@@ -923,7 +924,6 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
 static void collapse_huge_page(struct mm_struct *mm,
                                   unsigned long address,
                                   struct page **hpage,
-                                  struct vm_area_struct *vma,
                                   int node, int referenced)
 {
        pmd_t *pmd, _pmd;
@@ -933,6 +933,7 @@ static void collapse_huge_page(struct mm_struct *mm,
        spinlock_t *pmd_ptl, *pte_ptl;
        int isolated = 0, result = 0;
        struct mem_cgroup *memcg;
+       struct vm_area_struct *vma;
        unsigned long mmun_start;       /* For mmu_notifiers */
        unsigned long mmun_end;         /* For mmu_notifiers */
        gfp_t gfp;
@@ -961,7 +962,7 @@ static void collapse_huge_page(struct mm_struct *mm,
        }
 
        down_read(&mm->mmap_sem);
-       result = hugepage_vma_revalidate(mm, address);
+       result = hugepage_vma_revalidate(mm, address, &vma);
        if (result) {
                mem_cgroup_cancel_charge(new_page, memcg, true);
                up_read(&mm->mmap_sem);
@@ -994,7 +995,7 @@ static void collapse_huge_page(struct mm_struct *mm,
         * handled by the anon_vma lock + PG_lock.
         */
        down_write(&mm->mmap_sem);
-       result = hugepage_vma_revalidate(mm, address);
+       result = hugepage_vma_revalidate(mm, address, &vma);
        if (result)
                goto out;
        /* check if the pmd is still valid */
@@ -1202,7 +1203,7 @@ out_unmap:
        if (ret) {
                node = khugepaged_find_target_node();
                /* collapse_huge_page will return with the mmap_sem released */
-               collapse_huge_page(mm, address, hpage, vma, node, referenced);
+               collapse_huge_page(mm, address, hpage, node, referenced);
        }
 out:
        trace_mm_khugepaged_scan_pmd(mm, page, writable, referenced,