Merge branch 'akpm' (incoming from Andrew)

Merge second patch-bomb from Andrew Morton:
 - the rest of MM
 - zram updates
 - zswap updates
 - exit
 - procfs
 - exec
 - wait
 - crash dump
 - lib/idr
 - rapidio
 - adfs, affs, bfs, ufs
 - cris
 - Kconfig things
 - initramfs
 - small amount of IPC material
 - percpu enhancements
 - early ioremap support
 - various other misc things

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (156 commits)
  MAINTAINERS: update Intel C600 SAS driver maintainers
  fs/ufs: remove unused ufs_super_block_third pointer
  fs/ufs: remove unused ufs_super_block_second pointer
  fs/ufs: remove unused ufs_super_block_first pointer
  fs/ufs/super.c: add __init to init_inodecache()
  doc/kernel-parameters.txt: add early_ioremap_debug
  arm64: add early_ioremap support
  arm64: initialize pgprot info earlier in boot
  x86: use generic early_ioremap
  mm: create generic early_ioremap() support
  x86/mm: sparse warning fix for early_memremap
  lglock: map to spinlock when !CONFIG_SMP
  percpu: add preemption checks to __this_cpu ops
  vmstat: use raw_cpu_ops to avoid false positives on preemption checks
  slub: use raw_cpu_inc for incrementing statistics
  net: replace __this_cpu_inc in route.c with raw_cpu_inc
  modules: use raw_cpu_write for initialization of per cpu refcount.
  mm: use raw_cpu ops for determining current NUMA node
  percpu: add raw_cpu_ops
  slub: fix leak of 'name' in sysfs_slab_add
  ...

mm/zswap.c

@@ -89,6 +89,9 @@ static unsigned int zswap_max_pool_percent = 20;
 module_param_named(max_pool_percent,
 			zswap_max_pool_percent, uint, 0644);
 
+/* zbud_pool is shared by all of zswap backend  */
+static struct zbud_pool *zswap_pool;
+
 /*********************************
 * compression functions
 **********************************/
@@ -160,14 +163,14 @@ static void zswap_comp_exit(void)
  * rbnode - links the entry into red-black tree for the appropriate swap type
  * refcount - the number of outstanding reference to the entry. This is needed
  *            to protect against premature freeing of the entry by code
- *            concurent calls to load, invalidate, and writeback.  The lock
+ *            concurrent calls to load, invalidate, and writeback.  The lock
  *            for the zswap_tree structure that contains the entry must
  *            be held while changing the refcount.  Since the lock must
  *            be held, there is no reason to also make refcount atomic.
  * offset - the swap offset for the entry.  Index into the red-black tree.
- * handle - zsmalloc allocation handle that stores the compressed page data
+ * handle - zbud allocation handle that stores the compressed page data
  * length - the length in bytes of the compressed page data.  Needed during
- *           decompression
+ *          decompression
  */
 struct zswap_entry {
 	struct rb_node rbnode;
@@ -189,7 +192,6 @@ struct zswap_header {
 struct zswap_tree {
 	struct rb_root rbroot;
 	spinlock_t lock;
-	struct zbud_pool *pool;
 };
 
 static struct zswap_tree *zswap_trees[MAX_SWAPFILES];
@@ -202,7 +204,7 @@ static struct kmem_cache *zswap_entry_cache;
 static int zswap_entry_cache_create(void)
 {
 	zswap_entry_cache = KMEM_CACHE(zswap_entry, 0);
-	return (zswap_entry_cache == NULL);
+	return zswap_entry_cache == NULL;
 }
 
 static void zswap_entry_cache_destory(void)
@@ -282,16 +284,15 @@ static void zswap_rb_erase(struct rb_root *root, struct zswap_entry *entry)
 }
 
 /*
- * Carries out the common pattern of freeing and entry's zsmalloc allocation,
+ * Carries out the common pattern of freeing and entry's zbud allocation,
  * freeing the entry itself, and decrementing the number of stored pages.
  */
-static void zswap_free_entry(struct zswap_tree *tree,
-			struct zswap_entry *entry)
+static void zswap_free_entry(struct zswap_entry *entry)
 {
-	zbud_free(tree->pool, entry->handle);
+	zbud_free(zswap_pool, entry->handle);
 	zswap_entry_cache_free(entry);
 	atomic_dec(&zswap_stored_pages);
-	zswap_pool_pages = zbud_get_pool_size(tree->pool);
+	zswap_pool_pages = zbud_get_pool_size(zswap_pool);
 }
 
 /* caller must hold the tree lock */
@@ -311,7 +312,7 @@ static void zswap_entry_put(struct zswap_tree *tree,
 	BUG_ON(refcount < 0);
 	if (refcount == 0) {
 		zswap_rb_erase(&tree->rbroot, entry);
-		zswap_free_entry(tree, entry);
+		zswap_free_entry(entry);
 	}
 }
 
@@ -407,8 +408,8 @@ cleanup:
 **********************************/
 static bool zswap_is_full(void)
 {
-	return (totalram_pages * zswap_max_pool_percent / 100 <
-		zswap_pool_pages);
+	return totalram_pages * zswap_max_pool_percent / 100 <
+		zswap_pool_pages;
 }
 
 /*********************************
@@ -545,7 +546,6 @@ static int zswap_writeback_entry(struct zbud_pool *pool, unsigned long handle)
 	zbud_unmap(pool, handle);
 	tree = zswap_trees[swp_type(swpentry)];
 	offset = swp_offset(swpentry);
-	BUG_ON(pool != tree->pool);
 
 	/* find and ref zswap entry */
 	spin_lock(&tree->lock);
@@ -573,13 +573,13 @@ static int zswap_writeback_entry(struct zbud_pool *pool, unsigned long handle)
 	case ZSWAP_SWAPCACHE_NEW: /* page is locked */
 		/* decompress */
 		dlen = PAGE_SIZE;
-		src = (u8 *)zbud_map(tree->pool, entry->handle) +
+		src = (u8 *)zbud_map(zswap_pool, entry->handle) +
 			sizeof(struct zswap_header);
 		dst = kmap_atomic(page);
 		ret = zswap_comp_op(ZSWAP_COMPOP_DECOMPRESS, src,
 				entry->length, dst, &dlen);
 		kunmap_atomic(dst);
-		zbud_unmap(tree->pool, entry->handle);
+		zbud_unmap(zswap_pool, entry->handle);
 		BUG_ON(ret);
 		BUG_ON(dlen != PAGE_SIZE);
 
@@ -652,7 +652,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 	/* reclaim space if needed */
 	if (zswap_is_full()) {
 		zswap_pool_limit_hit++;
-		if (zbud_reclaim_page(tree->pool, 8)) {
+		if (zbud_reclaim_page(zswap_pool, 8)) {
 			zswap_reject_reclaim_fail++;
 			ret = -ENOMEM;
 			goto reject;
@@ -679,7 +679,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 
 	/* store */
 	len = dlen + sizeof(struct zswap_header);
-	ret = zbud_alloc(tree->pool, len, __GFP_NORETRY | __GFP_NOWARN,
+	ret = zbud_alloc(zswap_pool, len, __GFP_NORETRY | __GFP_NOWARN,
 		&handle);
 	if (ret == -ENOSPC) {
 		zswap_reject_compress_poor++;
@@ -689,11 +689,11 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 		zswap_reject_alloc_fail++;
 		goto freepage;
 	}
-	zhdr = zbud_map(tree->pool, handle);
+	zhdr = zbud_map(zswap_pool, handle);
 	zhdr->swpentry = swp_entry(type, offset);
 	buf = (u8 *)(zhdr + 1);
 	memcpy(buf, dst, dlen);
-	zbud_unmap(tree->pool, handle);
+	zbud_unmap(zswap_pool, handle);
 	put_cpu_var(zswap_dstmem);
 
 	/* populate entry */
@@ -716,7 +716,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 
 	/* update stats */
 	atomic_inc(&zswap_stored_pages);
-	zswap_pool_pages = zbud_get_pool_size(tree->pool);
+	zswap_pool_pages = zbud_get_pool_size(zswap_pool);
 
 	return 0;
 
@@ -752,13 +752,13 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset,
 
 	/* decompress */
 	dlen = PAGE_SIZE;
-	src = (u8 *)zbud_map(tree->pool, entry->handle) +
+	src = (u8 *)zbud_map(zswap_pool, entry->handle) +
 			sizeof(struct zswap_header);
 	dst = kmap_atomic(page);
 	ret = zswap_comp_op(ZSWAP_COMPOP_DECOMPRESS, src, entry->length,
 		dst, &dlen);
 	kunmap_atomic(dst);
-	zbud_unmap(tree->pool, entry->handle);
+	zbud_unmap(zswap_pool, entry->handle);
 	BUG_ON(ret);
 
 	spin_lock(&tree->lock);
@@ -804,11 +804,9 @@ static void zswap_frontswap_invalidate_area(unsigned type)
 	/* walk the tree and free everything */
 	spin_lock(&tree->lock);
 	rbtree_postorder_for_each_entry_safe(entry, n, &tree->rbroot, rbnode)
-		zswap_free_entry(tree, entry);
+		zswap_free_entry(entry);
 	tree->rbroot = RB_ROOT;
 	spin_unlock(&tree->lock);
-
-	zbud_destroy_pool(tree->pool);
 	kfree(tree);
 	zswap_trees[type] = NULL;
 }
@@ -822,20 +820,14 @@ static void zswap_frontswap_init(unsigned type)
 	struct zswap_tree *tree;
 
 	tree = kzalloc(sizeof(struct zswap_tree), GFP_KERNEL);
-	if (!tree)
-		goto err;
-	tree->pool = zbud_create_pool(GFP_KERNEL, &zswap_zbud_ops);
-	if (!tree->pool)
-		goto freetree;
+	if (!tree) {
+		pr_err("alloc failed, zswap disabled for swap type %d\n", type);
+		return;
+	}
+
 	tree->rbroot = RB_ROOT;
 	spin_lock_init(&tree->lock);
 	zswap_trees[type] = tree;
-	return;
-
-freetree:
-	kfree(tree);
-err:
-	pr_err("alloc failed, zswap disabled for swap type %d\n", type);
 }
 
 static struct frontswap_ops zswap_frontswap_ops = {
@@ -907,9 +899,16 @@ static int __init init_zswap(void)
 		return 0;
 
 	pr_info("loading zswap\n");
+
+	zswap_pool = zbud_create_pool(GFP_KERNEL, &zswap_zbud_ops);
+	if (!zswap_pool) {
+		pr_err("zbud pool creation failed\n");
+		goto error;
+	}
+
 	if (zswap_entry_cache_create()) {
 		pr_err("entry cache creation failed\n");
-		goto error;
+		goto cachefail;
 	}
 	if (zswap_comp_init()) {
 		pr_err("compressor initialization failed\n");
@@ -919,6 +918,7 @@ static int __init init_zswap(void)
 		pr_err("per-cpu initialization failed\n");
 		goto pcpufail;
 	}
+
 	frontswap_register_ops(&zswap_frontswap_ops);
 	if (zswap_debugfs_init())
 		pr_warn("debugfs initialization failed\n");
@@ -927,6 +927,8 @@ pcpufail:
 	zswap_comp_exit();
 compfail:
 	zswap_entry_cache_destory();
+cachefail:
+	zbud_destroy_pool(zswap_pool);
 error:
 	return -ENOMEM;
 }