Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 68 insertions, 27 deletions

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 102cc6fca3d3..735e01a0db6f 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -160,7 +160,6 @@ do_kmem_cache_create(char *name, size_t object_size, size_t size, size_t align,
 
 	s->refcount = 1;
 	list_add(&s->list, &slab_caches);
-	memcg_register_cache(s);
 out:
 	if (err)
 		return ERR_PTR(err);
@@ -205,6 +204,8 @@ kmem_cache_create(const char *name, size_t size, size_t align,
 	int err;
 
 	get_online_cpus();
+	get_online_mems();
+
 	mutex_lock(&slab_mutex);
 
 	err = kmem_cache_sanity_check(name, size);
@@ -239,6 +240,8 @@ kmem_cache_create(const char *name, size_t size, size_t align,
 
 out_unlock:
 	mutex_unlock(&slab_mutex);
+
+	put_online_mems();
 	put_online_cpus();
 
 	if (err) {
@@ -258,31 +261,29 @@ EXPORT_SYMBOL(kmem_cache_create);
 
 #ifdef CONFIG_MEMCG_KMEM
 /*
- * kmem_cache_create_memcg - Create a cache for a memory cgroup.
+ * memcg_create_kmem_cache - Create a cache for a memory cgroup.
  * @memcg: The memory cgroup the new cache is for.
  * @root_cache: The parent of the new cache.
+ * @memcg_name: The name of the memory cgroup (used for naming the new cache).
  *
  * This function attempts to create a kmem cache that will serve allocation
  * requests going from @memcg to @root_cache. The new cache inherits properties
  * from its parent.
  */
-void kmem_cache_create_memcg(struct mem_cgroup *memcg, struct kmem_cache *root_cache)
+struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
+					   struct kmem_cache *root_cache,
+					   const char *memcg_name)
 {
-	struct kmem_cache *s;
+	struct kmem_cache *s = NULL;
 	char *cache_name;
 
 	get_online_cpus();
-	mutex_lock(&slab_mutex);
+	get_online_mems();
 
-	/*
-	 * Since per-memcg caches are created asynchronously on first
-	 * allocation (see memcg_kmem_get_cache()), several threads can try to
-	 * create the same cache, but only one of them may succeed.
-	 */
-	if (cache_from_memcg_idx(root_cache, memcg_cache_id(memcg)))
-		goto out_unlock;
+	mutex_lock(&slab_mutex);
 
-	cache_name = memcg_create_cache_name(memcg, root_cache);
+	cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
+			       memcg_cache_id(memcg), memcg_name);
 	if (!cache_name)
 		goto out_unlock;
 
@@ -292,17 +293,19 @@ void kmem_cache_create_memcg(struct mem_cgroup *memcg, struct kmem_cache *root_c
 				 memcg, root_cache);
 	if (IS_ERR(s)) {
 		kfree(cache_name);
-		goto out_unlock;
+		s = NULL;
 	}
 
-	s->allocflags |= __GFP_KMEMCG;
-
 out_unlock:
 	mutex_unlock(&slab_mutex);
+
+	put_online_mems();
 	put_online_cpus();
+
+	return s;
 }
 
-static int kmem_cache_destroy_memcg_children(struct kmem_cache *s)
+static int memcg_cleanup_cache_params(struct kmem_cache *s)
 {
 	int rc;
 
@@ -311,13 +314,13 @@ static int kmem_cache_destroy_memcg_children(struct kmem_cache *s)
 		return 0;
 
 	mutex_unlock(&slab_mutex);
-	rc = __kmem_cache_destroy_memcg_children(s);
+	rc = __memcg_cleanup_cache_params(s);
 	mutex_lock(&slab_mutex);
 
 	return rc;
 }
 #else
-static int kmem_cache_destroy_memcg_children(struct kmem_cache *s)
+static int memcg_cleanup_cache_params(struct kmem_cache *s)
 {
 	return 0;
 }
@@ -332,27 +335,26 @@ void slab_kmem_cache_release(struct kmem_cache *s)
 void kmem_cache_destroy(struct kmem_cache *s)
 {
 	get_online_cpus();
+	get_online_mems();
+
 	mutex_lock(&slab_mutex);
 
 	s->refcount--;
 	if (s->refcount)
 		goto out_unlock;
 
-	if (kmem_cache_destroy_memcg_children(s) != 0)
+	if (memcg_cleanup_cache_params(s) != 0)
 		goto out_unlock;
 
-	list_del(&s->list);
-	memcg_unregister_cache(s);
-
 	if (__kmem_cache_shutdown(s) != 0) {
-		list_add(&s->list, &slab_caches);
-		memcg_register_cache(s);
 		printk(KERN_ERR "kmem_cache_destroy %s: "
 		       "Slab cache still has objects\n", s->name);
 		dump_stack();
 		goto out_unlock;
 	}
 
+	list_del(&s->list);
+
 	mutex_unlock(&slab_mutex);
 	if (s->flags & SLAB_DESTROY_BY_RCU)
 		rcu_barrier();
@@ -363,15 +365,36 @@ void kmem_cache_destroy(struct kmem_cache *s)
 #else
 	slab_kmem_cache_release(s);
 #endif
-	goto out_put_cpus;
+	goto out;
 
 out_unlock:
 	mutex_unlock(&slab_mutex);
-out_put_cpus:
+out:
+	put_online_mems();
 	put_online_cpus();
 }
 EXPORT_SYMBOL(kmem_cache_destroy);
 
+/**
+ * kmem_cache_shrink - Shrink a cache.
+ * @cachep: The cache to shrink.
+ *
+ * Releases as many slabs as possible for a cache.
+ * To help debugging, a zero exit status indicates all slabs were released.
+ */
+int kmem_cache_shrink(struct kmem_cache *cachep)
+{
+	int ret;
+
+	get_online_cpus();
+	get_online_mems();
+	ret = __kmem_cache_shrink(cachep);
+	put_online_mems();
+	put_online_cpus();
+	return ret;
+}
+EXPORT_SYMBOL(kmem_cache_shrink);
+
 int slab_is_available(void)
 {
 	return slab_state >= UP;
@@ -586,6 +609,24 @@ void __init create_kmalloc_caches(unsigned long flags)
 }
 #endif /* !CONFIG_SLOB */
 
+/*
+ * To avoid unnecessary overhead, we pass through large allocation requests
+ * directly to the page allocator. We use __GFP_COMP, because we will need to
+ * know the allocation order to free the pages properly in kfree.
+ */
+void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
+{
+	void *ret;
+	struct page *page;
+
+	flags |= __GFP_COMP;
+	page = alloc_kmem_pages(flags, order);
+	ret = page ? page_address(page) : NULL;
+	kmemleak_alloc(ret, size, 1, flags);
+	return ret;
+}
+EXPORT_SYMBOL(kmalloc_order);
+
 #ifdef CONFIG_TRACING
 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
 {