Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:

 - a few misc things

 - a few Y2038 fixes

 - ntfs fixes

 - arch/sh tweaks

 - ocfs2 updates

 - most of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (111 commits)
  mm/hmm.c: remove unused variables align_start and align_end
  fs/userfaultfd.c: remove redundant pointer uwq
  mm, vmacache: hash addresses based on pmd
  mm/list_lru: introduce list_lru_shrink_walk_irq()
  mm/list_lru.c: pass struct list_lru_node* as an argument to __list_lru_walk_one()
  mm/list_lru.c: move locking from __list_lru_walk_one() to its caller
  mm/list_lru.c: use list_lru_walk_one() in list_lru_walk_node()
  mm, swap: make CONFIG_THP_SWAP depend on CONFIG_SWAP
  mm/sparse: delete old sparse_init and enable new one
  mm/sparse: add new sparse_init_nid() and sparse_init()
  mm/sparse: move buffer init/fini to the common place
  mm/sparse: use the new sparse buffer functions in non-vmemmap
  mm/sparse: abstract sparse buffer allocations
  mm/hugetlb.c: don't zero 1GiB bootmem pages
  mm, page_alloc: double zone's batchsize
  mm/oom_kill.c: document oom_lock
  mm/hugetlb: remove gigantic page support for HIGHMEM
  mm, oom: remove sleep from under oom_lock
  kernel/dma: remove unsupported gfp_mask parameter from dma_alloc_from_contiguous()
  mm/cma: remove unsupported gfp_mask parameter from cma_alloc()
  ...

1 files changed, 9 insertions, 2 deletions

diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 6794490f25b2..b154fd2b084c 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -34,12 +34,15 @@ struct shrink_control {
 };
 
 #define SHRINK_STOP (~0UL)
+#define SHRINK_EMPTY (~0UL - 1)
 /*
  * A callback you can register to apply pressure to ageable caches.
  *
  * @count_objects should return the number of freeable items in the cache. If
- * there are no objects to free or the number of freeable items cannot be
- * determined, it should return 0. No deadlock checks should be done during the
+ * there are no objects to free, it should return SHRINK_EMPTY, while 0 is
+ * returned in cases of the number of freeable items cannot be determined
+ * or shrinker should skip this cache for this time (e.g., their number
+ * is below shrinkable limit). No deadlock checks should be done during the
  * count callback - the shrinker relies on aggregating scan counts that couldn't
  * be executed due to potential deadlocks to be run at a later call when the
  * deadlock condition is no longer pending.
@@ -66,6 +69,10 @@ struct shrinker {
 
 	/* These are for internal use */
 	struct list_head list;
+#ifdef CONFIG_MEMCG_KMEM
+	/* ID in shrinker_idr */
+	int id;
+#endif
 	/* objs pending delete, per node */
 	atomic_long_t *nr_deferred;
 };