2 files changed, 18 insertions, 3 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index d7d7165156ca..edfeb8cb23df 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -952,6 +952,8 @@ 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;
         }
@@ -959,6 +961,7 @@ 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;
diff --git a/mm/memory.c b/mm/memory.c
index 2bf9e110437c..1b7dc662bf9f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3486,6 +3486,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
         if (unlikely(is_vm_hugetlb_page(vma)))
                 return hugetlb_fault(mm, vma, address, flags);
 
+retry:
         pgd = pgd_offset(mm, address);
         pud = pud_alloc(mm, pgd, address);
         if (!pud)
@@ -3499,13 +3500,24 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                                                           pmd, flags);
         } else {
                 pmd_t orig_pmd = *pmd;
+                int ret;
+
                 barrier();
                 if (pmd_trans_huge(orig_pmd)) {
                         if (flags & FAULT_FLAG_WRITE &&
                             !pmd_write(orig_pmd) &&
-                            !pmd_trans_splitting(orig_pmd))
-                                return do_huge_pmd_wp_page(mm, vma, address,
-                                                           pmd, orig_pmd);
+                            !pmd_trans_splitting(orig_pmd)) {
+                                ret = do_huge_pmd_wp_page(mm, vma, address, pmd,
+                                                          orig_pmd);
+                                /*
+                                 * If COW results in an oom, the huge pmd will
+                                 * have been split, so retry the fault on the
+                                 * pte for a smaller charge.
+                                 */
+                                if (unlikely(ret & VM_FAULT_OOM))
+                                        goto retry;
+                                return ret;
+                        }
                         return 0;
                 }
         }