Merge branch 'akpm' (fixes from Andrew Morton)

Merge misc fixes from Andrew Morton.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (21 commits)
  mm: revert mremap pud_free anti-fix
  mm: fix BUG in __split_huge_page_pmd
  swap: fix set_blocksize race during swapon/swapoff
  procfs: call default get_unmapped_area on MMU-present architectures
  procfs: fix unintended truncation of returned mapped address
  writeback: fix negative bdi max pause
  percpu_refcount: export symbols
  fs: buffer: move allocation failure loop into the allocator
  mm: memcg: handle non-error OOM situations more gracefully
  tools/testing/selftests: fix uninitialized variable
  block/partitions/efi.c: treat size mismatch as a warning, not an error
  mm: hugetlb: initialize PG_reserved for tail pages of gigantic compound pages
  mm/zswap: bugfix: memory leak when re-swapon
  mm: /proc/pid/pagemap: inspect _PAGE_SOFT_DIRTY only on present pages
  mm: migration: do not lose soft dirty bit if page is in migration state
  gcov: MAINTAINERS: Add an entry for gcov
  mm/hugetlb.c: correct missing private flag clearing
  mm/vmscan.c: don't forget to free shrinker->nr_deferred
  ipc/sem.c: synchronize semop and semctl with IPC_RMID
  ipc: update locking scheme comments
  ...

1 files changed, 14 insertions, 6 deletions

diff --git a/mm/memory.c b/mm/memory.c
index ca0003947115..1311f26497e6 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -837,6 +837,8 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 					 */
 					make_migration_entry_read(&entry);
 					pte = swp_entry_to_pte(entry);
+					if (pte_swp_soft_dirty(*src_pte))
+						pte = pte_swp_mksoft_dirty(pte);
 					set_pte_at(src_mm, addr, src_pte, pte);
 				}
 			}
@@ -3863,15 +3865,21 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	 * space.  Kernel faults are handled more gracefully.
 	 */
 	if (flags & FAULT_FLAG_USER)
-		mem_cgroup_enable_oom();
+		mem_cgroup_oom_enable();
 
 	ret = __handle_mm_fault(mm, vma, address, flags);
 
-	if (flags & FAULT_FLAG_USER)
-		mem_cgroup_disable_oom();
-
-	if (WARN_ON(task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM)))
-		mem_cgroup_oom_synchronize();
+	if (flags & FAULT_FLAG_USER) {
+		mem_cgroup_oom_disable();
+                /*
+                 * The task may have entered a memcg OOM situation but
+                 * if the allocation error was handled gracefully (no
+                 * VM_FAULT_OOM), there is no need to kill anything.
+                 * Just clean up the OOM state peacefully.
+                 */
+                if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
+                        mem_cgroup_oom_synchronize(false);
+	}
 
 	return ret;
 }