Merge branch 'docs-move' of git://git.kernel.org/pub/scm/linux/kernel/git/rdunlap...

[deliverable/linux.git] / mm / huge_memory.c

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 470dcda10addbc68e1470c9bc8c92b5dba103623..615d9743a3cbad1ca19d745c45115eecb1c463f4 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1139,7 +1139,7 @@ static int __split_huge_page_splitting(struct page *page,
                 * We can't temporarily set the pmd to null in order
                 * to split it, the pmd must remain marked huge at all
                 * times or the VM won't take the pmd_trans_huge paths
-                * and it won't wait on the anon_vma->root->lock to
+                * and it won't wait on the anon_vma->root->mutex to
                 * serialize against split_huge_page*.
                 */
                pmdp_splitting_flush_notify(vma, address, pmd);
@@ -1333,7 +1333,7 @@ static int __split_huge_page_map(struct page *page,
        return ret;
 }
 
-/* must be called with anon_vma->root->lock hold */
+/* must be called with anon_vma->root->mutex hold */
 static void __split_huge_page(struct page *page,
                              struct anon_vma *anon_vma)
 {
@@ -1408,6 +1408,9 @@ out:
        return ret;
 }
 
+#define VM_NO_THP (VM_SPECIAL|VM_INSERTPAGE|VM_MIXEDMAP|VM_SAO| \
+                  VM_HUGETLB|VM_SHARED|VM_MAYSHARE)
+
 int hugepage_madvise(struct vm_area_struct *vma,
                     unsigned long *vm_flags, int advice)
 {
@@ -1416,11 +1419,7 @@ int hugepage_madvise(struct vm_area_struct *vma,
                /*
                 * Be somewhat over-protective like KSM for now!
                 */
-               if (*vm_flags & (VM_HUGEPAGE |
-                                VM_SHARED   | VM_MAYSHARE   |
-                                VM_PFNMAP   | VM_IO      | VM_DONTEXPAND |
-                                VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE |
-                                VM_MIXEDMAP | VM_SAO))
+               if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP))
                        return -EINVAL;
                *vm_flags &= ~VM_NOHUGEPAGE;
                *vm_flags |= VM_HUGEPAGE;
@@ -1436,11 +1435,7 @@ int hugepage_madvise(struct vm_area_struct *vma,
                /*
                 * Be somewhat over-protective like KSM for now!
                 */
-               if (*vm_flags & (VM_NOHUGEPAGE |
-                                VM_SHARED   | VM_MAYSHARE   |
-                                VM_PFNMAP   | VM_IO      | VM_DONTEXPAND |
-                                VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE |
-                                VM_MIXEDMAP | VM_SAO))
+               if (*vm_flags & (VM_NOHUGEPAGE | VM_NO_THP))
                        return -EINVAL;
                *vm_flags &= ~VM_HUGEPAGE;
                *vm_flags |= VM_NOHUGEPAGE;
@@ -1574,10 +1569,14 @@ int khugepaged_enter_vma_merge(struct vm_area_struct *vma)
                 * page fault if needed.
                 */
                return 0;
-       if (vma->vm_file || vma->vm_ops)
+       if (vma->vm_ops)
                /* khugepaged not yet working on file or special mappings */
                return 0;
-       VM_BUG_ON(is_linear_pfn_mapping(vma) || is_pfn_mapping(vma));
+       /*
+        * If is_pfn_mapping() is true is_learn_pfn_mapping() must be
+        * true too, verify it here.
+        */
+       VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP);
        hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
        hend = vma->vm_end & HPAGE_PMD_MASK;
        if (hstart < hend)
@@ -1772,12 +1771,9 @@ static void collapse_huge_page(struct mm_struct *mm,
 
        VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 #ifndef CONFIG_NUMA
+       up_read(&mm->mmap_sem);
        VM_BUG_ON(!*hpage);
        new_page = *hpage;
-       if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
-               up_read(&mm->mmap_sem);
-               return;
-       }
 #else
        VM_BUG_ON(*hpage);
        /*
@@ -1792,22 +1788,26 @@ static void collapse_huge_page(struct mm_struct *mm,
         */
        new_page = alloc_hugepage_vma(khugepaged_defrag(), vma, address,
                                      node, __GFP_OTHER_NODE);
+
+       /*
+        * After allocating the hugepage, release the mmap_sem read lock in
+        * preparation for taking it in write mode.
+        */
+       up_read(&mm->mmap_sem);
        if (unlikely(!new_page)) {
-               up_read(&mm->mmap_sem);
                count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
                *hpage = ERR_PTR(-ENOMEM);
                return;
        }
+#endif
+
        count_vm_event(THP_COLLAPSE_ALLOC);
        if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
-               up_read(&mm->mmap_sem);
+#ifdef CONFIG_NUMA
                put_page(new_page);
+#endif
                return;
        }
-#endif
-
-       /* after allocating the hugepage upgrade to mmap_sem write mode */
-       up_read(&mm->mmap_sem);
 
        /*
         * Prevent all access to pagetables with the exception of
@@ -1828,12 +1828,15 @@ static void collapse_huge_page(struct mm_struct *mm,
            (vma->vm_flags & VM_NOHUGEPAGE))
                goto out;
 
-       /* VM_PFNMAP vmas may have vm_ops null but vm_file set */
-       if (!vma->anon_vma || vma->vm_ops || vma->vm_file)
+       if (!vma->anon_vma || vma->vm_ops)
                goto out;
        if (is_vma_temporary_stack(vma))
                goto out;
-       VM_BUG_ON(is_linear_pfn_mapping(vma) || is_pfn_mapping(vma));
+       /*
+        * If is_pfn_mapping() is true is_learn_pfn_mapping() must be
+        * true too, verify it here.
+        */
+       VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP);
 
        pgd = pgd_offset(mm, address);
        if (!pgd_present(*pgd))
@@ -2066,13 +2069,16 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
                        progress++;
                        continue;
                }
-               /* VM_PFNMAP vmas may have vm_ops null but vm_file set */
-               if (!vma->anon_vma || vma->vm_ops || vma->vm_file)
+               if (!vma->anon_vma || vma->vm_ops)
                        goto skip;
                if (is_vma_temporary_stack(vma))
                        goto skip;
-
-               VM_BUG_ON(is_linear_pfn_mapping(vma) || is_pfn_mapping(vma));
+               /*
+                * If is_pfn_mapping() is true is_learn_pfn_mapping()
+                * must be true too, verify it here.
+                */
+               VM_BUG_ON(is_linear_pfn_mapping(vma) ||
+                         vma->vm_flags & VM_NO_THP);
 
                hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
                hend = vma->vm_end & HPAGE_PMD_MASK;