mm: thp: set the accessed flag for old pages on access fault

[pandora-kernel.git] / mm / huge_memory.c

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 36b3d98..9a33a2b 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -642,6 +642,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
                set_pmd_at(mm, haddr, pmd, entry);
                prepare_pmd_huge_pte(pgtable, mm);
                add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
+               mm->nr_ptes++;
                spin_unlock(&mm->page_table_lock);
        }
 
@@ -760,6 +761,7 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
        pmd = pmd_mkold(pmd_wrprotect(pmd));
        set_pmd_at(dst_mm, addr, dst_pmd, pmd);
        prepare_pmd_huge_pte(pgtable, dst_mm);
+       dst_mm->nr_ptes++;
 
        ret = 0;
 out_unlock:
@@ -788,6 +790,28 @@ pgtable_t get_pmd_huge_pte(struct mm_struct *mm)
        return pgtable;
 }
 
+void huge_pmd_set_accessed(struct mm_struct *mm,
+                          struct vm_area_struct *vma,
+                          unsigned long address,
+                          pmd_t *pmd, pmd_t orig_pmd,
+                          int dirty)
+{
+       pmd_t entry;
+       unsigned long haddr;
+
+       spin_lock(&mm->page_table_lock);
+       if (unlikely(!pmd_same(*pmd, orig_pmd)))
+               goto unlock;
+
+       entry = pmd_mkyoung(orig_pmd);
+       haddr = address & HPAGE_PMD_MASK;
+       if (pmdp_set_access_flags(vma, haddr, pmd, entry, dirty))
+               update_mmu_cache_pmd(vma, address, pmd);
+
+unlock:
+       spin_unlock(&mm->page_table_lock);
+}
+
 static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
                                        struct vm_area_struct *vma,
                                        unsigned long address,
@@ -858,7 +882,6 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
        }
        kfree(pages);
 
-       mm->nr_ptes++;
        smp_wmb(); /* make pte visible before pmd */
        pmd_populate(mm, pmd, pgtable);
        page_remove_rmap(page);
@@ -902,7 +925,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                entry = pmd_mkyoung(orig_pmd);
                entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
                if (pmdp_set_access_flags(vma, haddr, pmd, entry,  1))
-                       update_mmu_cache(vma, address, entry);
+                       update_mmu_cache(vma, address, pmd);
                ret |= VM_FAULT_WRITE;
                goto out_unlock;
        }
@@ -920,6 +943,8 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                count_vm_event(THP_FAULT_FALLBACK);
                ret = do_huge_pmd_wp_page_fallback(mm, vma, address,
                                                   pmd, orig_pmd, page, haddr);
+               if (ret & VM_FAULT_OOM)
+                       split_huge_page(page);
                put_page(page);
                goto out;
        }
@@ -927,6 +952,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 
        if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
                put_page(new_page);
+               split_huge_page(page);
                put_page(page);
                ret |= VM_FAULT_OOM;
                goto out;
@@ -949,7 +975,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                pmdp_clear_flush_notify(vma, haddr, pmd);
                page_add_new_anon_rmap(new_page, vma, haddr);
                set_pmd_at(mm, haddr, pmd, entry);
-               update_mmu_cache(vma, address, entry);
+               update_mmu_cache(vma, address, pmd);
                page_remove_rmap(page);
                put_page(page);
                ret |= VM_FAULT_WRITE;
@@ -1017,6 +1043,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
                        VM_BUG_ON(page_mapcount(page) < 0);
                        add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
                        VM_BUG_ON(!PageHead(page));
+                       tlb->mm->nr_ptes--;
                        spin_unlock(&tlb->mm->page_table_lock);
                        tlb_remove_page(tlb, page);
                        pte_free(tlb->mm, pgtable);
@@ -1356,7 +1383,6 @@ static int __split_huge_page_map(struct page *page,
                        pte_unmap(pte);
                }
 
-               mm->nr_ptes++;
                smp_wmb(); /* make pte visible before pmd */
                /*
                 * Up to this point the pmd is present and huge and
@@ -1967,9 +1993,8 @@ static void collapse_huge_page(struct mm_struct *mm,
        BUG_ON(!pmd_none(*pmd));
        page_add_new_anon_rmap(new_page, vma, address);
        set_pmd_at(mm, address, pmd, _pmd);
-       update_mmu_cache(vma, address, _pmd);
+       update_mmu_cache(vma, address, pmd);
        prepare_pmd_huge_pte(pgtable, mm);
-       mm->nr_ptes--;
        spin_unlock(&mm->page_table_lock);
 
 #ifndef CONFIG_NUMA
@@ -2064,7 +2089,7 @@ static void collect_mm_slot(struct mm_slot *mm_slot)
 {
        struct mm_struct *mm = mm_slot->mm;
 
-       VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock));
+       VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
 
        if (khugepaged_test_exit(mm)) {
                /* free mm_slot */
@@ -2094,7 +2119,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
        int progress = 0;
 
        VM_BUG_ON(!pages);
-       VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock));
+       VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
 
        if (khugepaged_scan.mm_slot)
                mm_slot = khugepaged_scan.mm_slot;