Merge branch 'akpm' (patches from Andrew)

Merge some more updates from Andrew Morton:

 - various hotfixes and minor things

 - hch's use_mm/unuse_mm clearnups

Subsystems affected by this patch series: mm/hugetlb, scripts, kcov,
lib, nilfs, checkpatch, lib, mm/debug, ocfs2, lib, misc.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kernel: set USER_DS in kthread_use_mm
  kernel: better document the use_mm/unuse_mm API contract
  kernel: move use_mm/unuse_mm to kthread.c
  kernel: move use_mm/unuse_mm to kthread.c
  stacktrace: cleanup inconsistent variable type
  lib: test get_count_order/long in test_bitops.c
  mm: add comments on pglist_data zones
  ocfs2: fix spelling mistake and grammar
  mm/debug_vm_pgtable: fix kernel crash by checking for THP support
  lib: fix bitmap_parse() on 64-bit big endian archs
  checkpatch: correct check for kernel parameters doc
  nilfs2: fix null pointer dereference at nilfs_segctor_do_construct()
  lib/lz4/lz4_decompress.c: document deliberate use of `&'
  kcov: check kcov_softirq in kcov_remote_stop()
  scripts/spelling: add a few more typos
  khugepaged: selftests: fix timeout condition in wait_for_scan()

drivers/vhost/vhost.c

@@ -14,7 +14,6 @@
 #include <linux/vhost.h>
 #include <linux/uio.h>
 #include <linux/mm.h>
-#include <linux/mmu_context.h>
 #include <linux/miscdevice.h>
 #include <linux/mutex.h>
 #include <linux/poll.h>
@@ -335,10 +334,8 @@ static int vhost_worker(void *data)
 	struct vhost_dev *dev = data;
 	struct vhost_work *work, *work_next;
 	struct llist_node *node;
-	mm_segment_t oldfs = get_fs();
 
-	set_fs(USER_DS);
-	use_mm(dev->mm);
+	kthread_use_mm(dev->mm);
 
 	for (;;) {
 		/* mb paired w/ kthread_stop */
@@ -366,8 +363,7 @@ static int vhost_worker(void *data)
 				schedule();
 		}
 	}
-	unuse_mm(dev->mm);
-	set_fs(oldfs);
+	kthread_unuse_mm(dev->mm);
 	return 0;
 }