Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:

 - misc fixes

 - ocfs2 updates

 - most of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
  mm: remove PG_highmem description
  tools, vm: new option to specify kpageflags file
  mm/swap.c: make functions and their kernel-doc agree
  mm, memory_hotplug: fix memmap initialization
  mm: correct comments regarding do_fault_around()
  mm: numa: do not trap faults on shared data section pages.
  hugetlb, mbind: fall back to default policy if vma is NULL
  hugetlb, mempolicy: fix the mbind hugetlb migration
  mm, hugetlb: further simplify hugetlb allocation API
  mm, hugetlb: get rid of surplus page accounting tricks
  mm, hugetlb: do not rely on overcommit limit during migration
  mm, hugetlb: integrate giga hugetlb more naturally to the allocation path
  mm, hugetlb: unify core page allocation accounting and initialization
  mm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytes
  mm/memcontrol.c: make local symbol static
  mm/hmm: fix uninitialized use of 'entry' in hmm_vma_walk_pmd()
  include/linux/mmzone.h: fix explanation of lower bits in the SPARSEMEM mem_map pointer
  mm/compaction.c: fix comment for try_to_compact_pages()
  mm/page_ext.c: make page_ext_init a noop when CONFIG_PAGE_EXTENSION but nothing uses it
  zsmalloc: use U suffix for negative literals being shifted
  ...

1 files changed, 9 insertions, 6 deletions

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index ea4ff259b671..b7e2268dfc9a 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1399,8 +1399,7 @@ static void collapse_shmem(struct mm_struct *mm,
 		}
 
 		if (page_mapped(page))
-			unmap_mapping_range(mapping, index << PAGE_SHIFT,
-					PAGE_SIZE, 0);
+			unmap_mapping_pages(mapping, index, 1, false);
 
 		spin_lock_irq(&mapping->tree_lock);
 
@@ -1674,10 +1673,14 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 	spin_unlock(&khugepaged_mm_lock);
 
 	mm = mm_slot->mm;
-	down_read(&mm->mmap_sem);
-	if (unlikely(khugepaged_test_exit(mm)))
-		vma = NULL;
-	else
+	/*
+	 * Don't wait for semaphore (to avoid long wait times).  Just move to
+	 * the next mm on the list.
+	 */
+	vma = NULL;
+	if (unlikely(!down_read_trylock(&mm->mmap_sem)))
+		goto breakouterloop_mmap_sem;
+	if (likely(!khugepaged_test_exit(mm)))
 		vma = find_vma(mm, khugepaged_scan.address);
 
 	progress++;