Merge remote-tracking branch 'origin/next' into kvm-ppc-next

Conflicts:
	mm/Kconfig

CMA DMA split and ZSWAP introduction were conflicting, fix up manually.

37 files changed, 2862 insertions, 953 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index 81bcb4bd422..6cdd2704330 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -501,3 +501,45 @@ config CMA_DEBUG
 	  messages for every CMA call as well as various messages while
 	  processing calls such as dma_alloc_from_contiguous().
 	  This option does not affect warning and error messages.
+
+config ZBUD
+	tristate
+	default n
+	help
+	  A special purpose allocator for storing compressed pages.
+	  It is designed to store up to two compressed pages per physical
+	  page.  While this design limits storage density, it has simple and
+	  deterministic reclaim properties that make it preferable to a higher
+	  density approach when reclaim will be used.
+
+config ZSWAP
+	bool "Compressed cache for swap pages (EXPERIMENTAL)"
+	depends on FRONTSWAP && CRYPTO=y
+	select CRYPTO_LZO
+	select ZBUD
+	default n
+	help
+	  A lightweight compressed cache for swap pages.  It takes
+	  pages that are in the process of being swapped out and attempts to
+	  compress them into a dynamically allocated RAM-based memory pool.
+	  This can result in a significant I/O reduction on swap device and,
+	  in the case where decompressing from RAM is faster that swap device
+	  reads, can also improve workload performance.
+
+	  This is marked experimental because it is a new feature (as of
+	  v3.11) that interacts heavily with memory reclaim.  While these
+	  interactions don't cause any known issues on simple memory setups,
+	  they have not be fully explored on the large set of potential
+	  configurations and workloads that exist.
+
+config MEM_SOFT_DIRTY
+	bool "Track memory changes"
+	depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY
+	select PROC_PAGE_MONITOR
+	help
+	  This option enables memory changes tracking by introducing a
+	  soft-dirty bit on pte-s. This bit it set when someone writes
+	  into a page just as regular dirty bit, but unlike the latter
+	  it can be cleared by hands.
+
+	  See Documentation/vm/soft-dirty.txt for more details.
diff --git a/mm/Makefile b/mm/Makefile
index 72c5acb9345..f00803386a6 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o
 obj-$(CONFIG_BOUNCE)	+= bounce.o
 obj-$(CONFIG_SWAP)	+= page_io.o swap_state.o swapfile.o
 obj-$(CONFIG_FRONTSWAP)	+= frontswap.o
+obj-$(CONFIG_ZSWAP)	+= zswap.o
 obj-$(CONFIG_HAS_DMA)	+= dmapool.o
 obj-$(CONFIG_HUGETLBFS)	+= hugetlb.o
 obj-$(CONFIG_NUMA) 	+= mempolicy.o
@@ -58,3 +59,4 @@ obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
 obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
 obj-$(CONFIG_CLEANCACHE) += cleancache.o
 obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
+obj-$(CONFIG_ZBUD)	+= zbud.o
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 50251749225..d014ee5fcbb 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -515,7 +515,6 @@ EXPORT_SYMBOL(bdi_destroy);
 int bdi_setup_and_register(struct backing_dev_info *bdi, char *name,
 			   unsigned int cap)
 {
-	char tmp[32];
 	int err;
 
 	bdi->name = name;
@@ -524,8 +523,8 @@ int bdi_setup_and_register(struct backing_dev_info *bdi, char *name,
 	if (err)
 		return err;
 
-	sprintf(tmp, "%.28s%s", name, "-%d");
-	err = bdi_register(bdi, NULL, tmp, atomic_long_inc_return(&bdi_seq));
+	err = bdi_register(bdi, NULL, "%.28s-%ld", name,
+			   atomic_long_inc_return(&bdi_seq));
 	if (err) {
 		bdi_destroy(bdi);
 		return err;
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 2b0bcb019ec..6ab7744e692 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -241,33 +241,26 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
 	return count;
 }
 
-static void reset_node_lowmem_managed_pages(pg_data_t *pgdat)
+static int reset_managed_pages_done __initdata;
+
+static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
 {
 	struct zone *z;
 
-	/*
-	 * In free_area_init_core(), highmem zone's managed_pages is set to
-	 * present_pages, and bootmem allocator doesn't allocate from highmem
-	 * zones. So there's no need to recalculate managed_pages because all
-	 * highmem pages will be managed by the buddy system. Here highmem
-	 * zone also includes highmem movable zone.
-	 */
+	if (reset_managed_pages_done)
+		return;
+
 	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
-		if (!is_highmem(z))
-			z->managed_pages = 0;
+		z->managed_pages = 0;
 }
 
-/**
- * free_all_bootmem_node - release a node's free pages to the buddy allocator
- * @pgdat: node to be released
- *
- * Returns the number of pages actually released.
- */
-unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
+void __init reset_all_zones_managed_pages(void)
 {
-	register_page_bootmem_info_node(pgdat);
-	reset_node_lowmem_managed_pages(pgdat);
-	return free_all_bootmem_core(pgdat->bdata);
+	struct pglist_data *pgdat;
+
+	for_each_online_pgdat(pgdat)
+		reset_node_managed_pages(pgdat);
+	reset_managed_pages_done = 1;
 }
 
 /**
@@ -279,14 +272,14 @@ unsigned long __init free_all_bootmem(void)
 {
 	unsigned long total_pages = 0;
 	bootmem_data_t *bdata;
-	struct pglist_data *pgdat;
 
-	for_each_online_pgdat(pgdat)
-		reset_node_lowmem_managed_pages(pgdat);
+	reset_all_zones_managed_pages();
 
 	list_for_each_entry(bdata, &bdata_list, list)
 		total_pages += free_all_bootmem_core(bdata);
 
+	totalram_pages += total_pages;
+
 	return total_pages;
 }
 
diff --git a/mm/filemap.c b/mm/filemap.c
index 7905fe721aa..4b51ac1acae 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1539,12 +1539,12 @@ static void do_sync_mmap_readahead(struct vm_area_struct *vma,
 	struct address_space *mapping = file->f_mapping;
 
 	/* If we don't want any read-ahead, don't bother */
-	if (VM_RandomReadHint(vma))
+	if (vma->vm_flags & VM_RAND_READ)
 		return;
 	if (!ra->ra_pages)
 		return;
 
-	if (VM_SequentialReadHint(vma)) {
+	if (vma->vm_flags & VM_SEQ_READ) {
 		page_cache_sync_readahead(mapping, ra, file, offset,
 					  ra->ra_pages);
 		return;
@@ -1584,7 +1584,7 @@ static void do_async_mmap_readahead(struct vm_area_struct *vma,
 	struct address_space *mapping = file->f_mapping;
 
 	/* If we don't want any read-ahead, don't bother */
-	if (VM_RandomReadHint(vma))
+	if (vma->vm_flags & VM_RAND_READ)
 		return;
 	if (ra->mmap_miss > 0)
 		ra->mmap_miss--;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 362c329b83f..243e710c603 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -729,8 +729,8 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
 		pmd_t entry;
 		entry = mk_huge_pmd(page, vma);
 		page_add_new_anon_rmap(page, vma, haddr);
+		pgtable_trans_huge_deposit(mm, pmd, pgtable);
 		set_pmd_at(mm, haddr, pmd, entry);
-		pgtable_trans_huge_deposit(mm, pgtable);
 		add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
 		mm->nr_ptes++;
 		spin_unlock(&mm->page_table_lock);
@@ -771,8 +771,8 @@ static bool set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
 	entry = mk_pmd(zero_page, vma->vm_page_prot);
 	entry = pmd_wrprotect(entry);
 	entry = pmd_mkhuge(entry);
+	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	set_pmd_at(mm, haddr, pmd, entry);
-	pgtable_trans_huge_deposit(mm, pgtable);
 	mm->nr_ptes++;
 	return true;
 }
@@ -916,8 +916,8 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 
 	pmdp_set_wrprotect(src_mm, addr, src_pmd);
 	pmd = pmd_mkold(pmd_wrprotect(pmd));
+	pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
 	set_pmd_at(dst_mm, addr, dst_pmd, pmd);
-	pgtable_trans_huge_deposit(dst_mm, pgtable);
 	dst_mm->nr_ptes++;
 
 	ret = 0;
@@ -987,7 +987,7 @@ static int do_huge_pmd_wp_zero_page_fallback(struct mm_struct *mm,
 	pmdp_clear_flush(vma, haddr, pmd);
 	/* leave pmd empty until pte is filled */
 
-	pgtable = pgtable_trans_huge_withdraw(mm);
+	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 	pmd_populate(mm, &_pmd, pgtable);
 
 	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
@@ -1085,7 +1085,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
 	pmdp_clear_flush(vma, haddr, pmd);
 	/* leave pmd empty until pte is filled */
 
-	pgtable = pgtable_trans_huge_withdraw(mm);
+	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 	pmd_populate(mm, &_pmd, pgtable);
 
 	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
@@ -1265,7 +1265,9 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
 		 * young bit, instead of the current set_pmd_at.
 		 */
 		_pmd = pmd_mkyoung(pmd_mkdirty(*pmd));
-		set_pmd_at(mm, addr & HPAGE_PMD_MASK, pmd, _pmd);
+		if (pmdp_set_access_flags(vma, addr & HPAGE_PMD_MASK,
+					  pmd, _pmd,  1))
+			update_mmu_cache_pmd(vma, addr, pmd);
 	}
 	if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) {
 		if (page->mapping && trylock_page(page)) {
@@ -1358,9 +1360,15 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		struct page *page;
 		pgtable_t pgtable;
 		pmd_t orig_pmd;
-		pgtable = pgtable_trans_huge_withdraw(tlb->mm);
+		/*
+		 * For architectures like ppc64 we look at deposited pgtable
+		 * when calling pmdp_get_and_clear. So do the
+		 * pgtable_trans_huge_withdraw after finishing pmdp related
+		 * operations.
+		 */
 		orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd);
 		tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
+		pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
 		if (is_huge_zero_pmd(orig_pmd)) {
 			tlb->mm->nr_ptes--;
 			spin_unlock(&tlb->mm->page_table_lock);
@@ -1429,7 +1437,7 @@ int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
 	if (ret == 1) {
 		pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
 		VM_BUG_ON(!pmd_none(*new_pmd));
-		set_pmd_at(mm, new_addr, new_pmd, pmd);
+		set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
 		spin_unlock(&mm->page_table_lock);
 	}
 out:
@@ -1691,7 +1699,7 @@ static int __split_huge_page_map(struct page *page,
 	pmd = page_check_address_pmd(page, mm, address,
 				     PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG);
 	if (pmd) {
-		pgtable = pgtable_trans_huge_withdraw(mm);
+		pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 		pmd_populate(mm, &_pmd, pgtable);
 
 		haddr = address;
@@ -2359,9 +2367,9 @@ static void collapse_huge_page(struct mm_struct *mm,
 	spin_lock(&mm->page_table_lock);
 	BUG_ON(!pmd_none(*pmd));
 	page_add_new_anon_rmap(new_page, vma, address);
+	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	set_pmd_at(mm, address, pmd, _pmd);
 	update_mmu_cache_pmd(vma, address, pmd);
-	pgtable_trans_huge_deposit(mm, pgtable);
 	spin_unlock(&mm->page_table_lock);
 
 	*hpage = NULL;
@@ -2667,7 +2675,7 @@ static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
 	pmdp_clear_flush(vma, haddr, pmd);
 	/* leave pmd empty until pte is filled */
 
-	pgtable = pgtable_trans_huge_withdraw(mm);
+	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 	pmd_populate(mm, &_pmd, pgtable);
 
 	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index aed085ad11a..83aff0a4d09 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -319,7 +319,7 @@ unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
 
 	hstate = hstate_vma(vma);
 
-	return 1UL << (hstate->order + PAGE_SHIFT);
+	return 1UL << huge_page_shift(hstate);
 }
 EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
 
@@ -1263,7 +1263,7 @@ static void __init gather_bootmem_prealloc(void)
 		 * side-effects, like CommitLimit going negative.
 		 */
 		if (h->order > (MAX_ORDER - 1))
-			totalram_pages += 1 << h->order;
+			adjust_managed_page_count(page, 1 << h->order);
 	}
 }
 
diff --git a/mm/internal.h b/mm/internal.h
index 8562de0a519..4390ac6c106 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -32,11 +32,6 @@ static inline void set_page_refcounted(struct page *page)
 	set_page_count(page, 1);
 }
 
-static inline void __put_page(struct page *page)
-{
-	atomic_dec(&page->_count);
-}
-
 static inline void __get_page_tail_foll(struct page *page,
 					bool get_page_head)
 {
diff --git a/mm/memblock.c b/mm/memblock.c
index c5fad932fa5..a847bfe6f3b 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -566,7 +566,7 @@ int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
 /**
  * __next_free_mem_range - next function for for_each_free_mem_range()
  * @idx: pointer to u64 loop variable
- * @nid: nid: node selector, %MAX_NUMNODES for all nodes
+ * @nid: node selector, %MAX_NUMNODES for all nodes
  * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
  * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
  * @out_nid: ptr to int for nid of the range, can be %NULL
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 194721839cf..d12ca6f3c29 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -187,10 +187,6 @@ struct mem_cgroup_per_node {
 	struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
 };
 
-struct mem_cgroup_lru_info {
-	struct mem_cgroup_per_node *nodeinfo[0];
-};
-
 /*
  * Cgroups above their limits are maintained in a RB-Tree, independent of
  * their hierarchy representation
@@ -267,28 +263,10 @@ struct mem_cgroup {
 	/* vmpressure notifications */
 	struct vmpressure vmpressure;
 
-	union {
-		/*
-		 * the counter to account for mem+swap usage.
-		 */
-		struct res_counter memsw;
-
-		/*
-		 * rcu_freeing is used only when freeing struct mem_cgroup,
-		 * so put it into a union to avoid wasting more memory.
-		 * It must be disjoint from the css field.  It could be
-		 * in a union with the res field, but res plays a much
-		 * larger part in mem_cgroup life than memsw, and might
-		 * be of interest, even at time of free, when debugging.
-		 * So share rcu_head with the less interesting memsw.
-		 */
-		struct rcu_head rcu_freeing;
-		/*
-		 * We also need some space for a worker in deferred freeing.
-		 * By the time we call it, rcu_freeing is no longer in use.
-		 */
-		struct work_struct work_freeing;
-	};
+	/*
+	 * the counter to account for mem+swap usage.
+	 */
+	struct res_counter memsw;
 
 	/*
 	 * the counter to account for kernel memory usage.
@@ -303,8 +281,6 @@ struct mem_cgroup {
 	bool		oom_lock;
 	atomic_t	under_oom;
 
-	atomic_t	refcnt;
-
 	int	swappiness;
 	/* OOM-Killer disable */
 	int		oom_kill_disable;
@@ -366,14 +342,8 @@ struct mem_cgroup {
 	atomic_t	numainfo_updating;
 #endif
 
-	/*
-	 * Per cgroup active and inactive list, similar to the
-	 * per zone LRU lists.
-	 *
-	 * WARNING: This has to be the last element of the struct. Don't
-	 * add new fields after this point.
-	 */
-	struct mem_cgroup_lru_info info;
+	struct mem_cgroup_per_node *nodeinfo[0];
+	/* WARNING: nodeinfo must be the last member here */
 };
 
 static size_t memcg_size(void)
@@ -416,6 +386,11 @@ static void memcg_kmem_clear_activated(struct mem_cgroup *memcg)
 
 static void memcg_kmem_mark_dead(struct mem_cgroup *memcg)
 {
+	/*
+	 * Our caller must use css_get() first, because memcg_uncharge_kmem()
+	 * will call css_put() if it sees the memcg is dead.
+	 */
+	smp_wmb();
 	if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags))
 		set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags);
 }
@@ -508,9 +483,6 @@ enum res_type {
  */
 static DEFINE_MUTEX(memcg_create_mutex);
 
-static void mem_cgroup_get(struct mem_cgroup *memcg);
-static void mem_cgroup_put(struct mem_cgroup *memcg);
-
 static inline
 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
 {
@@ -561,15 +533,15 @@ void sock_update_memcg(struct sock *sk)
 		 */
 		if (sk->sk_cgrp) {
 			BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
-			mem_cgroup_get(sk->sk_cgrp->memcg);
+			css_get(&sk->sk_cgrp->memcg->css);
 			return;
 		}
 
 		rcu_read_lock();
 		memcg = mem_cgroup_from_task(current);
 		cg_proto = sk->sk_prot->proto_cgroup(memcg);
-		if (!mem_cgroup_is_root(memcg) && memcg_proto_active(cg_proto)) {
-			mem_cgroup_get(memcg);
+		if (!mem_cgroup_is_root(memcg) &&
+		    memcg_proto_active(cg_proto) && css_tryget(&memcg->css)) {
 			sk->sk_cgrp = cg_proto;
 		}
 		rcu_read_unlock();
@@ -583,7 +555,7 @@ void sock_release_memcg(struct sock *sk)
 		struct mem_cgroup *memcg;
 		WARN_ON(!sk->sk_cgrp->memcg);
 		memcg = sk->sk_cgrp->memcg;
-		mem_cgroup_put(memcg);
+		css_put(&sk->sk_cgrp->memcg->css);
 	}
 }
 
@@ -683,7 +655,7 @@ static struct mem_cgroup_per_zone *
 mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid)
 {
 	VM_BUG_ON((unsigned)nid >= nr_node_ids);
-	return &memcg->info.nodeinfo[nid]->zoneinfo[zid];
+	return &memcg->nodeinfo[nid]->zoneinfo[zid];
 }
 
 struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
@@ -1148,6 +1120,58 @@ skip_node:
 	return NULL;
 }
 
+static void mem_cgroup_iter_invalidate(struct mem_cgroup *root)
+{
+	/*
+	 * When a group in the hierarchy below root is destroyed, the
+	 * hierarchy iterator can no longer be trusted since it might
+	 * have pointed to the destroyed group.  Invalidate it.
+	 */
+	atomic_inc(&root->dead_count);
+}
+
+static struct mem_cgroup *
+mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter,
+		     struct mem_cgroup *root,
+		     int *sequence)
+{
+	struct mem_cgroup *position = NULL;
+	/*
+	 * A cgroup destruction happens in two stages: offlining and
+	 * release.  They are separated by a RCU grace period.
+	 *
+	 * If the iterator is valid, we may still race with an
+	 * offlining.  The RCU lock ensures the object won't be
+	 * released, tryget will fail if we lost the race.
+	 */
+	*sequence = atomic_read(&root->dead_count);
+	if (iter->last_dead_count == *sequence) {
+		smp_rmb();
+		position = iter->last_visited;
+		if (position && !css_tryget(&position->css))
+			position = NULL;
+	}
+	return position;
+}
+
+static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter,
+				   struct mem_cgroup *last_visited,
+				   struct mem_cgroup *new_position,
+				   int sequence)
+{
+	if (last_visited)
+		css_put(&last_visited->css);
+	/*
+	 * We store the sequence count from the time @last_visited was
+	 * loaded successfully instead of rereading it here so that we
+	 * don't lose destruction events in between.  We could have
+	 * raced with the destruction of @new_position after all.
+	 */
+	iter->last_visited = new_position;
+	smp_wmb();
+	iter->last_dead_count = sequence;
+}
+
 /**
  * mem_cgroup_iter - iterate over memory cgroup hierarchy
  * @root: hierarchy root
@@ -1171,7 +1195,6 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 {
 	struct mem_cgroup *memcg = NULL;
 	struct mem_cgroup *last_visited = NULL;
-	unsigned long uninitialized_var(dead_count);
 
 	if (mem_cgroup_disabled())
 		return NULL;
@@ -1191,6 +1214,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 	rcu_read_lock();
 	while (!memcg) {
 		struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
+		int uninitialized_var(seq);
 
 		if (reclaim) {
 			int nid = zone_to_nid(reclaim->zone);
@@ -1204,37 +1228,13 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 				goto out_unlock;
 			}
 
-			/*
-			 * If the dead_count mismatches, a destruction
-			 * has happened or is happening concurrently.
-			 * If the dead_count matches, a destruction
-			 * might still happen concurrently, but since
-			 * we checked under RCU, that destruction
-			 * won't free the object until we release the
-			 * RCU reader lock.  Thus, the dead_count
-			 * check verifies the pointer is still valid,
-			 * css_tryget() verifies the cgroup pointed to
-			 * is alive.
-			 */
-			dead_count = atomic_read(&root->dead_count);
-			if (dead_count == iter->last_dead_count) {
-				smp_rmb();
-				last_visited = iter->last_visited;
-				if (last_visited &&
-				    !css_tryget(&last_visited->css))
-					last_visited = NULL;
-			}
+			last_visited = mem_cgroup_iter_load(iter, root, &seq);
 		}
 
 		memcg = __mem_cgroup_iter_next(root, last_visited);
 
 		if (reclaim) {
-			if (last_visited)
-				css_put(&last_visited->css);
-
-			iter->last_visited = memcg;
-			smp_wmb();
-			iter->last_dead_count = dead_count;
+			mem_cgroup_iter_update(iter, last_visited, memcg, seq);
 
 			if (!memcg)
 				iter->generation++;
@@ -1448,11 +1448,12 @@ static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
 	return ret;
 }
 
-int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
+bool task_in_mem_cgroup(struct task_struct *task,
+			const struct mem_cgroup *memcg)
 {
-	int ret;
 	struct mem_cgroup *curr = NULL;
 	struct task_struct *p;
+	bool ret;
 
 	p = find_lock_task_mm(task);
 	if (p) {
@@ -1464,14 +1465,14 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
 		 * killer still needs to detect if they have already been oom
 		 * killed to prevent needlessly killing additional tasks.
 		 */
-		task_lock(task);
+		rcu_read_lock();
 		curr = mem_cgroup_from_task(task);
 		if (curr)
 			css_get(&curr->css);
-		task_unlock(task);
+		rcu_read_unlock();
 	}
 	if (!curr)
-		return 0;
+		return false;
 	/*
 	 * We should check use_hierarchy of "memcg" not "curr". Because checking
 	 * use_hierarchy of "curr" here make this function true if hierarchy is
@@ -3031,8 +3032,16 @@ static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size)
 	if (res_counter_uncharge(&memcg->kmem, size))
 		return;
 
+	/*
+	 * Releases a reference taken in kmem_cgroup_css_offline in case
+	 * this last uncharge is racing with the offlining code or it is
+	 * outliving the memcg existence.
+	 *
+	 * The memory barrier imposed by test&clear is paired with the
+	 * explicit one in memcg_kmem_mark_dead().
+	 */
 	if (memcg_kmem_test_and_clear_dead(memcg))
-		mem_cgroup_put(memcg);
+		css_put(&memcg->css);
 }
 
 void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep)
@@ -3223,7 +3232,7 @@ void memcg_release_cache(struct kmem_cache *s)
 	list_del(&s->memcg_params->list);
 	mutex_unlock(&memcg->slab_caches_mutex);
 
-	mem_cgroup_put(memcg);
+	css_put(&memcg->css);
 out:
 	kfree(s->memcg_params);
 }
@@ -3383,16 +3392,18 @@ static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
 
 	mutex_lock(&memcg_cache_mutex);
 	new_cachep = cachep->memcg_params->memcg_caches[idx];
-	if (new_cachep)
+	if (new_cachep) {
+		css_put(&memcg->css);
 		goto out;
+	}
 
 	new_cachep = kmem_cache_dup(memcg, cachep);
 	if (new_cachep == NULL) {
 		new_cachep = cachep;
+		css_put(&memcg->css);
 		goto out;
 	}
 
-	mem_cgroup_get(memcg);
 	atomic_set(&new_cachep->memcg_params->nr_pages , 0);
 
 	cachep->memcg_params->memcg_caches[idx] = new_cachep;
@@ -3480,8 +3491,6 @@ static void memcg_create_cache_work_func(struct work_struct *w)
 
 	cw = container_of(w, struct create_work, work);
 	memcg_create_kmem_cache(cw->memcg, cw->cachep);
-	/* Drop the reference gotten when we enqueued. */
-	css_put(&cw->memcg->css);
 	kfree(cw);
 }
 
@@ -3618,6 +3627,34 @@ __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order)
 	int ret;
 
 	*_memcg = NULL;
+
+	/*
+	 * Disabling accounting is only relevant for some specific memcg
+	 * internal allocations. Therefore we would initially not have such
+	 * check here, since direct calls to the page allocator that are marked
+	 * with GFP_KMEMCG only happen outside memcg core. We are mostly
+	 * concerned with cache allocations, and by having this test at
+	 * memcg_kmem_get_cache, we are already able to relay the allocation to
+	 * the root cache and bypass the memcg cache altogether.
+	 *
+	 * There is one exception, though: the SLUB allocator does not create
+	 * large order caches, but rather service large kmallocs directly from
+	 * the page allocator. Therefore, the following sequence when backed by
+	 * the SLUB allocator:
+	 *
+	 * 	memcg_stop_kmem_account();
+	 * 	kmalloc(<large_number>)
+	 * 	memcg_resume_kmem_account();
+	 *
+	 * would effectively ignore the fact that we should skip accounting,
+	 * since it will drive us directly to this function without passing
+	 * through the cache selector memcg_kmem_get_cache. Such large
+	 * allocations are extremely rare but can happen, for instance, for the
+	 * cache arrays. We bring this test here.
+	 */
+	if (!current->mm || current->memcg_kmem_skip_account)
+		return true;
+
 	memcg = try_get_mem_cgroup_from_mm(current->mm);
 
 	/*
@@ -4171,12 +4208,12 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype,
 	unlock_page_cgroup(pc);
 	/*
 	 * even after unlock, we have memcg->res.usage here and this memcg
-	 * will never be freed.
+	 * will never be freed, so it's safe to call css_get().
 	 */
 	memcg_check_events(memcg, page);
 	if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
 		mem_cgroup_swap_statistics(memcg, true);
-		mem_cgroup_get(memcg);
+		css_get(&memcg->css);
 	}
 	/*
 	 * Migration does not charge the res_counter for the
@@ -4288,7 +4325,7 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
 
 	/*
 	 * record memcg information,  if swapout && memcg != NULL,
-	 * mem_cgroup_get() was called in uncharge().
+	 * css_get() was called in uncharge().
 	 */
 	if (do_swap_account && swapout && memcg)
 		swap_cgroup_record(ent, css_id(&memcg->css));
@@ -4319,7 +4356,7 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent)
 		if (!mem_cgroup_is_root(memcg))
 			res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
 		mem_cgroup_swap_statistics(memcg, false);
-		mem_cgroup_put(memcg);
+		css_put(&memcg->css);
 	}
 	rcu_read_unlock();
 }
@@ -4353,11 +4390,14 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry,
 		 * This function is only called from task migration context now.
 		 * It postpones res_counter and refcount handling till the end
 		 * of task migration(mem_cgroup_clear_mc()) for performance
-		 * improvement. But we cannot postpone mem_cgroup_get(to)
-		 * because if the process that has been moved to @to does
-		 * swap-in, the refcount of @to might be decreased to 0.
+		 * improvement. But we cannot postpone css_get(to)  because if
+		 * the process that has been moved to @to does swap-in, the
+		 * refcount of @to might be decreased to 0.
+		 *
+		 * We are in attach() phase, so the cgroup is guaranteed to be
+		 * alive, so we can just call css_get().
 		 */
-		mem_cgroup_get(to);
+		css_get(&to->css);
 		return 0;
 	}
 	return -EINVAL;
@@ -5136,14 +5176,6 @@ static int memcg_update_kmem_limit(struct cgroup *cont, u64 val)
 		 * starts accounting before all call sites are patched
 		 */
 		memcg_kmem_set_active(memcg);
-
-		/*
-		 * kmem charges can outlive the cgroup. In the case of slab
-		 * pages, for instance, a page contain objects from various
-		 * processes, so it is unfeasible to migrate them away. We
-		 * need to reference count the memcg because of that.
-		 */
-		mem_cgroup_get(memcg);
 	} else
 		ret = res_counter_set_limit(&memcg->kmem, val);
 out:
@@ -5176,16 +5208,16 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg)
 		goto out;
 
 	/*
-	 * destroy(), called if we fail, will issue static_key_slow_inc() and
-	 * mem_cgroup_put() if kmem is enabled. We have to either call them
-	 * unconditionally, or clear the KMEM_ACTIVE flag. I personally find
-	 * this more consistent, since it always leads to the same destroy path
+	 * __mem_cgroup_free() will issue static_key_slow_dec() because this
+	 * memcg is active already. If the later initialization fails then the
+	 * cgroup core triggers the cleanup so we do not have to do it here.
 	 */
-	mem_cgroup_get(memcg);
 	static_key_slow_inc(&memcg_kmem_enabled_key);
 
 	mutex_lock(&set_limit_mutex);
+	memcg_stop_kmem_account();
 	ret = memcg_update_cache_sizes(memcg);
+	memcg_resume_kmem_account();
 	mutex_unlock(&set_limit_mutex);
 out:
 	return ret;
@@ -5864,23 +5896,43 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
 	return mem_cgroup_sockets_init(memcg, ss);
 }
 
-static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
+static void memcg_destroy_kmem(struct mem_cgroup *memcg)
 {
 	mem_cgroup_sockets_destroy(memcg);
+}
+
+static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
+{
+	if (!memcg_kmem_is_active(memcg))
+		return;
+
+	/*
+	 * kmem charges can outlive the cgroup. In the case of slab
+	 * pages, for instance, a page contain objects from various
+	 * processes. As we prevent from taking a reference for every
+	 * such allocation we have to be careful when doing uncharge
+	 * (see memcg_uncharge_kmem) and here during offlining.
+	 *
+	 * The idea is that that only the _last_ uncharge which sees
+	 * the dead memcg will drop the last reference. An additional
+	 * reference is taken here before the group is marked dead
+	 * which is then paired with css_put during uncharge resp. here.
+	 *
+	 * Although this might sound strange as this path is called from
+	 * css_offline() when the referencemight have dropped down to 0
+	 * and shouldn't be incremented anymore (css_tryget would fail)
+	 * we do not have other options because of the kmem allocations
+	 * lifetime.
+	 */
+	css_get(&memcg->css);
 
 	memcg_kmem_mark_dead(memcg);
 
 	if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0)
 		return;
 
-	/*
-	 * Charges already down to 0, undo mem_cgroup_get() done in the charge
-	 * path here, being careful not to race with memcg_uncharge_kmem: it is
-	 * possible that the charges went down to 0 between mark_dead and the
-	 * res_counter read, so in that case, we don't need the put
-	 */
 	if (memcg_kmem_test_and_clear_dead(memcg))
-		mem_cgroup_put(memcg);
+		css_put(&memcg->css);
 }
 #else
 static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
@@ -5888,7 +5940,11 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
 	return 0;
 }
 
-static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
+static void memcg_destroy_kmem(struct mem_cgroup *memcg)
+{
+}
+
+static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
 {
 }
 #endif
@@ -6058,13 +6114,13 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
 		mz->on_tree = false;
 		mz->memcg = memcg;
 	}
-	memcg->info.nodeinfo[node] = pn;
+	memcg->nodeinfo[node] = pn;
 	return 0;
 }
 
 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
 {
-	kfree(memcg->info.nodeinfo[node]);
+	kfree(memcg->nodeinfo[node]);
 }
 
 static struct mem_cgroup *mem_cgroup_alloc(void)
@@ -6137,49 +6193,6 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
 		vfree(memcg);
 }
 
-
-/*
- * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
- * but in process context.  The work_freeing structure is overlaid
- * on the rcu_freeing structure, which itself is overlaid on memsw.
- */
-static void free_work(struct work_struct *work)
-{
-	struct mem_cgroup *memcg;
-
-	memcg = container_of(work, struct mem_cgroup, work_freeing);
-	__mem_cgroup_free(memcg);
-}
-
-static void free_rcu(struct rcu_head *rcu_head)
-{
-	struct mem_cgroup *memcg;
-
-	memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing);
-	INIT_WORK(&memcg->work_freeing, free_work);
-	schedule_work(&memcg->work_freeing);
-}
-
-static void mem_cgroup_get(struct mem_cgroup *memcg)
-{
-	atomic_inc(&memcg->refcnt);
-}
-
-static void __mem_cgroup_put(struct mem_cgroup *memcg, int count)
-{
-	if (atomic_sub_and_test(count, &memcg->refcnt)) {
-		struct mem_cgroup *parent = parent_mem_cgroup(memcg);
-		call_rcu(&memcg->rcu_freeing, free_rcu);
-		if (parent)
-			mem_cgroup_put(parent);
-	}
-}
-
-static void mem_cgroup_put(struct mem_cgroup *memcg)
-{
-	__mem_cgroup_put(memcg, 1);
-}
-
 /*
  * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
  */
@@ -6239,7 +6252,6 @@ mem_cgroup_css_alloc(struct cgroup *cont)
 
 	memcg->last_scanned_node = MAX_NUMNODES;
 	INIT_LIST_HEAD(&memcg->oom_notify);
-	atomic_set(&memcg->refcnt, 1);
 	memcg->move_charge_at_immigrate = 0;
 	mutex_init(&memcg->thresholds_lock);
 	spin_lock_init(&memcg->move_lock);
@@ -6275,12 +6287,9 @@ mem_cgroup_css_online(struct cgroup *cont)
 		res_counter_init(&memcg->kmem, &parent->kmem);
 
 		/*
-		 * We increment refcnt of the parent to ensure that we can
-		 * safely access it on res_counter_charge/uncharge.
-		 * This refcnt will be decremented when freeing this
-		 * mem_cgroup(see mem_cgroup_put).
+		 * No need to take a reference to the parent because cgroup
+		 * core guarantees its existence.
 		 */
-		mem_cgroup_get(parent);
 	} else {
 		res_counter_init(&memcg->res, NULL);
 		res_counter_init(&memcg->memsw, NULL);
@@ -6296,16 +6305,6 @@ mem_cgroup_css_online(struct cgroup *cont)
 
 	error = memcg_init_kmem(memcg, &mem_cgroup_subsys);
 	mutex_unlock(&memcg_create_mutex);
-	if (error) {
-		/*
-		 * We call put now because our (and parent's) refcnts
-		 * are already in place. mem_cgroup_put() will internally
-		 * call __mem_cgroup_free, so return directly
-		 */
-		mem_cgroup_put(memcg);
-		if (parent->use_hierarchy)
-			mem_cgroup_put(parent);
-	}
 	return error;
 }
 
@@ -6317,20 +6316,22 @@ static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg)
 	struct mem_cgroup *parent = memcg;
 
 	while ((parent = parent_mem_cgroup(parent)))
-		atomic_inc(&parent->dead_count);
+		mem_cgroup_iter_invalidate(parent);
 
 	/*
 	 * if the root memcg is not hierarchical we have to check it
 	 * explicitely.
 	 */
 	if (!root_mem_cgroup->use_hierarchy)
-		atomic_inc(&root_mem_cgroup->dead_count);
+		mem_cgroup_iter_invalidate(root_mem_cgroup);
 }
 
 static void mem_cgroup_css_offline(struct cgroup *cont)
 {
 	struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 
+	kmem_cgroup_css_offline(memcg);
+
 	mem_cgroup_invalidate_reclaim_iterators(memcg);
 	mem_cgroup_reparent_charges(memcg);
 	mem_cgroup_destroy_all_caches(memcg);
@@ -6340,9 +6341,8 @@ static void mem_cgroup_css_free(struct cgroup *cont)
 {
 	struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 
-	kmem_cgroup_destroy(memcg);
-
-	mem_cgroup_put(memcg);
+	memcg_destroy_kmem(memcg);
+	__mem_cgroup_free(memcg);
 }
 
 #ifdef CONFIG_MMU
@@ -6651,6 +6651,7 @@ static void __mem_cgroup_clear_mc(void)
 {
 	struct mem_cgroup *from = mc.from;
 	struct mem_cgroup *to = mc.to;
+	int i;
 
 	/* we must uncharge all the leftover precharges from mc.to */
 	if (mc.precharge) {
@@ -6671,7 +6672,9 @@ static void __mem_cgroup_clear_mc(void)
 		if (!mem_cgroup_is_root(mc.from))
 			res_counter_uncharge(&mc.from->memsw,
 						PAGE_SIZE * mc.moved_swap);
-		__mem_cgroup_put(mc.from, mc.moved_swap);
+
+		for (i = 0; i < mc.moved_swap; i++)
+			css_put(&mc.from->css);
 
 		if (!mem_cgroup_is_root(mc.to)) {
 			/*
@@ -6681,7 +6684,7 @@ static void __mem_cgroup_clear_mc(void)
 			res_counter_uncharge(&mc.to->res,
 						PAGE_SIZE * mc.moved_swap);
 		}
-		/* we've already done mem_cgroup_get(mc.to) */
+		/* we've already done css_get(mc.to) */
 		mc.moved_swap = 0;
 	}
 	memcg_oom_recover(from);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ceb0c7f1932..2c13aa7a016 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1410,7 +1410,8 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags)
 
 	/*
 	 * Isolate the page, so that it doesn't get reallocated if it
-	 * was free.
+	 * was free. This flag should be kept set until the source page
+	 * is freed and PG_hwpoison on it is set.
 	 */
 	set_migratetype_isolate(p, true);
 	/*
@@ -1433,7 +1434,6 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags)
 		/* Not a free page */
 		ret = 1;
 	}
-	unset_migratetype_isolate(p, MIGRATE_MOVABLE);
 	unlock_memory_hotplug();
 	return ret;
 }
@@ -1494,7 +1494,6 @@ static int soft_offline_huge_page(struct page *page, int flags)
 		atomic_long_add(1 << compound_trans_order(hpage),
 				&num_poisoned_pages);
 	}
-	/* keep elevated page count for bad page */
 	return ret;
 }
 
@@ -1559,7 +1558,7 @@ int soft_offline_page(struct page *page, int flags)
 			atomic_long_inc(&num_poisoned_pages);
 		}
 	}
-	/* keep elevated page count for bad page */
+	unset_migratetype_isolate(page, MIGRATE_MOVABLE);
 	return ret;
 }
 
@@ -1625,7 +1624,22 @@ static int __soft_offline_page(struct page *page, int flags)
 			if (ret > 0)
 				ret = -EIO;
 		} else {
+			/*
+			 * After page migration succeeds, the source page can
+			 * be trapped in pagevec and actual freeing is delayed.
+			 * Freeing code works differently based on PG_hwpoison,
+			 * so there's a race. We need to make sure that the
+			 * source page should be freed back to buddy before
+			 * setting PG_hwpoison.
+			 */
+			if (!is_free_buddy_page(page))
+				lru_add_drain_all();
+			if (!is_free_buddy_page(page))
+				drain_all_pages();
 			SetPageHWPoison(page);
+			if (!is_free_buddy_page(page))
+				pr_info("soft offline: %#lx: page leaked\n",
+					pfn);
 			atomic_long_inc(&num_poisoned_pages);
 		}
 	} else {
diff --git a/mm/memory.c b/mm/memory.c
index 95d0cce6358..1ce2e2a734f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -82,7 +82,6 @@ EXPORT_SYMBOL(max_mapnr);
 EXPORT_SYMBOL(mem_map);
 #endif
 
-unsigned long num_physpages;
 /*
  * A number of key systems in x86 including ioremap() rely on the assumption
  * that high_memory defines the upper bound on direct map memory, then end
@@ -92,7 +91,6 @@ unsigned long num_physpages;
  */
 void * high_memory;
 
-EXPORT_SYMBOL(num_physpages);
 EXPORT_SYMBOL(high_memory);
 
 /*
@@ -1101,6 +1099,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
 	spinlock_t *ptl;
 	pte_t *start_pte;
 	pte_t *pte;
+	unsigned long range_start = addr;
 
 again:
 	init_rss_vec(rss);
@@ -1151,7 +1150,7 @@ again:
 				if (pte_dirty(ptent))
 					set_page_dirty(page);
 				if (pte_young(ptent) &&
-				    likely(!VM_SequentialReadHint(vma)))
+				    likely(!(vma->vm_flags & VM_SEQ_READ)))
 					mark_page_accessed(page);
 				rss[MM_FILEPAGES]--;
 			}
@@ -1206,12 +1205,14 @@ again:
 		force_flush = 0;
 
 #ifdef HAVE_GENERIC_MMU_GATHER
-		tlb->start = addr;
-		tlb->end = end;
+		tlb->start = range_start;
+		tlb->end = addr;
 #endif
 		tlb_flush_mmu(tlb);
-		if (addr != end)
+		if (addr != end) {
+			range_start = addr;
 			goto again;
+		}
 	}
 
 	return addr;
@@ -2904,7 +2905,7 @@ static inline void unmap_mapping_range_tree(struct rb_root *root,
 			details->first_index, details->last_index) {
 
 		vba = vma->vm_pgoff;
-		vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1;
+		vea = vba + vma_pages(vma) - 1;
 		/* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
 		zba = details->first_index;
 		if (zba < vba)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 1ad92b46753..ca1dd3aa5ee 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -75,7 +75,7 @@ static struct resource *register_memory_resource(u64 start, u64 size)
 	res->end = start + size - 1;
 	res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 	if (request_resource(&iomem_resource, res) < 0) {
-		printk("System RAM resource %pR cannot be added\n", res);
+		pr_debug("System RAM resource %pR cannot be added\n", res);
 		kfree(res);
 		res = NULL;
 	}
@@ -101,12 +101,9 @@ void get_page_bootmem(unsigned long info,  struct page *page,
 	atomic_inc(&page->_count);
 }
 
-/* reference to __meminit __free_pages_bootmem is valid
- * so use __ref to tell modpost not to generate a warning */
-void __ref put_page_bootmem(struct page *page)
+void put_page_bootmem(struct page *page)
 {
 	unsigned long type;
-	static DEFINE_MUTEX(ppb_lock);
 
 	type = (unsigned long) page->lru.next;
 	BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
@@ -116,17 +113,8 @@ void __ref put_page_bootmem(struct page *page)
 		ClearPagePrivate(page);
 		set_page_private(page, 0);
 		INIT_LIST_HEAD(&page->lru);
-
-		/*
-		 * Please refer to comment for __free_pages_bootmem()
-		 * for why we serialize here.
-		 */
-		mutex_lock(&ppb_lock);
-		__free_pages_bootmem(page, 0);
-		mutex_unlock(&ppb_lock);
-		totalram_pages++;
+		free_reserved_page(page);
 	}
-
 }
 
 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
@@ -220,13 +208,13 @@ void register_page_bootmem_info_node(struct pglist_data *pgdat)
 	pfn = pgdat->node_start_pfn;
 	end_pfn = pgdat_end_pfn(pgdat);
 
-	/* register_section info */
+	/* register section info */
 	for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 		/*
 		 * Some platforms can assign the same pfn to multiple nodes - on
 		 * node0 as well as nodeN.  To avoid registering a pfn against
 		 * multiple nodes we check that this pfn does not already
-		 * reside in some other node.
+		 * reside in some other nodes.
 		 */
 		if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node))
 			register_page_bootmem_info_section(pfn);
@@ -309,7 +297,7 @@ static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2,
 	/* can't move pfns which are higher than @z2 */
 	if (end_pfn > zone_end_pfn(z2))
 		goto out_fail;
-	/* the move out part mast at the left most of @z2 */
+	/* the move out part must be at the left most of @z2 */
 	if (start_pfn > z2->zone_start_pfn)
 		goto out_fail;
 	/* must included/overlap */
@@ -775,29 +763,18 @@ EXPORT_SYMBOL_GPL(restore_online_page_callback);
 
 void __online_page_set_limits(struct page *page)
 {
-	unsigned long pfn = page_to_pfn(page);
-
-	if (pfn >= num_physpages)
-		num_physpages = pfn + 1;
 }
 EXPORT_SYMBOL_GPL(__online_page_set_limits);
 
 void __online_page_increment_counters(struct page *page)
 {
-	totalram_pages++;
-
-#ifdef CONFIG_HIGHMEM
-	if (PageHighMem(page))
-		totalhigh_pages++;
-#endif
+	adjust_managed_page_count(page, 1);
 }
 EXPORT_SYMBOL_GPL(__online_page_increment_counters);
 
 void __online_page_free(struct page *page)
 {
-	ClearPageReserved(page);
-	init_page_count(page);
-	__free_page(page);
+	__free_reserved_page(page);
 }
 EXPORT_SYMBOL_GPL(__online_page_free);
 
@@ -918,6 +895,7 @@ static void node_states_set_node(int node, struct memory_notify *arg)
 
 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
 {
+	unsigned long flags;
 	unsigned long onlined_pages = 0;
 	struct zone *zone;
 	int need_zonelists_rebuild = 0;
@@ -936,19 +914,19 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
 	if ((zone_idx(zone) > ZONE_NORMAL || online_type == ONLINE_MOVABLE) &&
 	    !can_online_high_movable(zone)) {
 		unlock_memory_hotplug();
-		return -1;
+		return -EINVAL;
 	}
 
 	if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) {
 		if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) {
 			unlock_memory_hotplug();
-			return -1;
+			return -EINVAL;
 		}
 	}
 	if (online_type == ONLINE_MOVABLE && zone_idx(zone) == ZONE_MOVABLE - 1) {
 		if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) {
 			unlock_memory_hotplug();
-			return -1;
+			return -EINVAL;
 		}
 	}
 
@@ -994,9 +972,12 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
 		return ret;
 	}
 
-	zone->managed_pages += onlined_pages;
 	zone->present_pages += onlined_pages;
+
+	pgdat_resize_lock(zone->zone_pgdat, &flags);
 	zone->zone_pgdat->node_present_pages += onlined_pages;
+	pgdat_resize_unlock(zone->zone_pgdat, &flags);
+
 	if (onlined_pages) {
 		node_states_set_node(zone_to_nid(zone), &arg);
 		if (need_zonelists_rebuild)
@@ -1487,6 +1468,7 @@ static int __ref __offline_pages(unsigned long start_pfn,
 	unsigned long pfn, nr_pages, expire;
 	long offlined_pages;
 	int ret, drain, retry_max, node;
+	unsigned long flags;
 	struct zone *zone;
 	struct memory_notify arg;
 
@@ -1578,10 +1560,12 @@ repeat:
 	/* reset pagetype flags and makes migrate type to be MOVABLE */
 	undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
 	/* removal success */
-	zone->managed_pages -= offlined_pages;
+	adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
 	zone->present_pages -= offlined_pages;
+
+	pgdat_resize_lock(zone->zone_pgdat, &flags);
 	zone->zone_pgdat->node_present_pages -= offlined_pages;
-	totalram_pages -= offlined_pages;
+	pgdat_resize_unlock(zone->zone_pgdat, &flags);
 
 	init_per_zone_wmark_min();
 
@@ -1621,6 +1605,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
 {
 	return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ);
 }
+#endif /* CONFIG_MEMORY_HOTREMOVE */
 
 /**
  * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
@@ -1634,7 +1619,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
  *
  * Returns the return value of func.
  */
-static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
+int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
 		void *arg, int (*func)(struct memory_block *, void *))
 {
 	struct memory_block *mem = NULL;
@@ -1671,24 +1656,7 @@ static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
 	return 0;
 }
 
-/**
- * offline_memory_block_cb - callback function for offlining memory block
- * @mem: the memory block to be offlined
- * @arg: buffer to hold error msg
- *
- * Always return 0, and put the error msg in arg if any.
- */
-static int offline_memory_block_cb(struct memory_block *mem, void *arg)
-{
-	int *ret = arg;
-	int error = offline_memory_block(mem);
-
-	if (error != 0 && *ret == 0)
-		*ret = error;
-
-	return 0;
-}
-
+#ifdef CONFIG_MEMORY_HOTREMOVE
 static int is_memblock_offlined_cb(struct memory_block *mem, void *arg)
 {
 	int ret = !is_memblock_offlined(mem);
@@ -1814,54 +1782,22 @@ void try_offline_node(int nid)
 }
 EXPORT_SYMBOL(try_offline_node);
 
-int __ref remove_memory(int nid, u64 start, u64 size)
+void __ref remove_memory(int nid, u64 start, u64 size)
 {
-	unsigned long start_pfn, end_pfn;
-	int ret = 0;
-	int retry = 1;
-
-	start_pfn = PFN_DOWN(start);
-	end_pfn = PFN_UP(start + size - 1);
-
-	/*
-	 * When CONFIG_MEMCG is on, one memory block may be used by other
-	 * blocks to store page cgroup when onlining pages. But we don't know
-	 * in what order pages are onlined. So we iterate twice to offline
-	 * memory:
-	 * 1st iterate: offline every non primary memory block.
-	 * 2nd iterate: offline primary (i.e. first added) memory block.
-	 */
-repeat:
-	walk_memory_range(start_pfn, end_pfn, &ret,
-			  offline_memory_block_cb);
-	if (ret) {
-		if (!retry)
-			return ret;
-
-		retry = 0;
-		ret = 0;
-		goto repeat;
-	}
+	int ret;
 
 	lock_memory_hotplug();
 
 	/*
-	 * we have offlined all memory blocks like this:
-	 *   1. lock memory hotplug
-	 *   2. offline a memory block
-	 *   3. unlock memory hotplug
-	 *
-	 * repeat step1-3 to offline the memory block. All memory blocks
-	 * must be offlined before removing memory. But we don't hold the
-	 * lock in the whole operation. So we should check whether all
-	 * memory blocks are offlined.
+	 * All memory blocks must be offlined before removing memory.  Check
+	 * whether all memory blocks in question are offline and trigger a BUG()
+	 * if this is not the case.
 	 */
-
-	ret = walk_memory_range(start_pfn, end_pfn, NULL,
+	ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL,
 				is_memblock_offlined_cb);
 	if (ret) {
 		unlock_memory_hotplug();
-		return ret;
+		BUG();
 	}
 
 	/* remove memmap entry */
@@ -1872,17 +1808,6 @@ repeat:
 	try_offline_node(nid);
 
 	unlock_memory_hotplug();
-
-	return 0;
 }
-#else
-int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
-{
-	return -EINVAL;
-}
-int remove_memory(int nid, u64 start, u64 size)
-{
-	return -EINVAL;
-}
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 EXPORT_SYMBOL_GPL(remove_memory);
+#endif /* CONFIG_MEMORY_HOTREMOVE */
diff --git a/mm/mm_init.c b/mm/mm_init.c
index c280a02ea11..633c08863fd 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -9,6 +9,8 @@
 #include <linux/init.h>
 #include <linux/kobject.h>
 #include <linux/export.h>
+#include <linux/memory.h>
+#include <linux/notifier.h>
 #include "internal.h"
 
 #ifdef CONFIG_DEBUG_MEMORY_INIT
@@ -147,6 +149,51 @@ early_param("mminit_loglevel", set_mminit_loglevel);
 struct kobject *mm_kobj;
 EXPORT_SYMBOL_GPL(mm_kobj);
 
+#ifdef CONFIG_SMP
+s32 vm_committed_as_batch = 32;
+
+static void __meminit mm_compute_batch(void)
+{
+	u64 memsized_batch;
+	s32 nr = num_present_cpus();
+	s32 batch = max_t(s32, nr*2, 32);
+
+	/* batch size set to 0.4% of (total memory/#cpus), or max int32 */
+	memsized_batch = min_t(u64, (totalram_pages/nr)/256, 0x7fffffff);
+
+	vm_committed_as_batch = max_t(s32, memsized_batch, batch);
+}
+
+static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
+					unsigned long action, void *arg)
+{
+	switch (action) {
+	case MEM_ONLINE:
+	case MEM_OFFLINE:
+		mm_compute_batch();
+	default:
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block compute_batch_nb __meminitdata = {
+	.notifier_call = mm_compute_batch_notifier,
+	.priority = IPC_CALLBACK_PRI, /* use lowest priority */
+};
+
+static int __init mm_compute_batch_init(void)
+{
+	mm_compute_batch();
+	register_hotmemory_notifier(&compute_batch_nb);
+
+	return 0;
+}
+
+__initcall(mm_compute_batch_init);
+
+#endif
+
 static int __init mm_sysfs_init(void)
 {
 	mm_kobj = kobject_create_and_add("mm", kernel_kobj);
diff --git a/mm/mmap.c b/mm/mmap.c
index f681e1842fa..fbad7b09109 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -955,7 +955,7 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
 	if (is_mergeable_vma(vma, file, vm_flags) &&
 	    is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
 		pgoff_t vm_pglen;
-		vm_pglen = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+		vm_pglen = vma_pages(vma);
 		if (vma->vm_pgoff + vm_pglen == vm_pgoff)
 			return 1;
 	}
@@ -1358,18 +1358,19 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
 
 	if (!(flags & MAP_ANONYMOUS)) {
 		audit_mmap_fd(fd, flags);
-		if (unlikely(flags & MAP_HUGETLB))
-			return -EINVAL;
 		file = fget(fd);
 		if (!file)
 			goto out;
 		if (is_file_hugepages(file))
 			len = ALIGN(len, huge_page_size(hstate_file(file)));
+		retval = -EINVAL;
+		if (unlikely(flags & MAP_HUGETLB && !is_file_hugepages(file)))
+			goto out_fput;
 	} else if (flags & MAP_HUGETLB) {
 		struct user_struct *user = NULL;
-		struct hstate *hs = hstate_sizelog((flags >> MAP_HUGE_SHIFT) &
-						   SHM_HUGE_MASK);
+		struct hstate *hs;
 
+		hs = hstate_sizelog((flags >> MAP_HUGE_SHIFT) & SHM_HUGE_MASK);
 		if (!hs)
 			return -EINVAL;
 
@@ -1391,6 +1392,7 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
 	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
 
 	retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+out_fput:
 	if (file)
 		fput(file);
 out:
@@ -1876,15 +1878,6 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 }
 #endif	
 
-void arch_unmap_area(struct mm_struct *mm, unsigned long addr)
-{
-	/*
-	 * Is this a new hole at the lowest possible address?
-	 */
-	if (addr >= TASK_UNMAPPED_BASE && addr < mm->free_area_cache)
-		mm->free_area_cache = addr;
-}
-
 /*
  * This mmap-allocator allocates new areas top-down from below the
  * stack's low limit (the base):
@@ -1941,19 +1934,6 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 }
 #endif
 
-void arch_unmap_area_topdown(struct mm_struct *mm, unsigned long addr)
-{
-	/*
-	 * Is this a new hole at the highest possible address?
-	 */
-	if (addr > mm->free_area_cache)
-		mm->free_area_cache = addr;
-
-	/* dont allow allocations above current base */
-	if (mm->free_area_cache > mm->mmap_base)
-		mm->free_area_cache = mm->mmap_base;
-}
-
 unsigned long
 get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
 		unsigned long pgoff, unsigned long flags)
@@ -2374,7 +2354,6 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma,
 {
 	struct vm_area_struct **insertion_point;
 	struct vm_area_struct *tail_vma = NULL;
-	unsigned long addr;
 
 	insertion_point = (prev ? &prev->vm_next : &mm->mmap);
 	vma->vm_prev = NULL;
@@ -2391,11 +2370,6 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma,
 	} else
 		mm->highest_vm_end = prev ? prev->vm_end : 0;
 	tail_vma->vm_next = NULL;
-	if (mm->unmap_area == arch_unmap_area)
-		addr = prev ? prev->vm_end : mm->mmap_base;
-	else
-		addr = vma ?  vma->vm_start : mm->mmap_base;
-	mm->unmap_area(mm, addr);
 	mm->mmap_cache = NULL;		/* Kill the cache. */
 }
 
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 6725ff18337..93e6089cb45 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -315,7 +315,7 @@ void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm)
 
 	/*
 	 * Wait for any running method to finish, of course including
-	 * ->release if it was run by mmu_notifier_relase instead of us.
+	 * ->release if it was run by mmu_notifier_release instead of us.
 	 */
 	synchronize_srcu(&srcu);
 
diff --git a/mm/mremap.c b/mm/mremap.c
index 463a25705ac..457d34ef3bf 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -126,7 +126,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
 			continue;
 		pte = ptep_get_and_clear(mm, old_addr, old_pte);
 		pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
-		set_pte_at(mm, new_addr, new_pte, pte);
+		set_pte_at(mm, new_addr, new_pte, pte_mksoft_dirty(pte));
 	}
 
 	arch_leave_lazy_mmu_mode();
@@ -456,13 +456,14 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 	unsigned long charged = 0;
 	bool locked = false;
 
-	down_write(&current->mm->mmap_sem);
-
 	if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE))
-		goto out;
+		return ret;
+
+	if (flags & MREMAP_FIXED && !(flags & MREMAP_MAYMOVE))
+		return ret;
 
 	if (addr & ~PAGE_MASK)
-		goto out;
+		return ret;
 
 	old_len = PAGE_ALIGN(old_len);
 	new_len = PAGE_ALIGN(new_len);
@@ -473,12 +474,13 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 	 * a zero new-len is nonsensical.
 	 */
 	if (!new_len)
-		goto out;
+		return ret;
+
+	down_write(&current->mm->mmap_sem);
 
 	if (flags & MREMAP_FIXED) {
-		if (flags & MREMAP_MAYMOVE)
-			ret = mremap_to(addr, old_len, new_addr, new_len,
-					&locked);
+		ret = mremap_to(addr, old_len, new_addr, new_len,
+				&locked);
 		goto out;
 	}
 
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index bdd3fa2fc73..61107cf55bb 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -137,20 +137,25 @@ static unsigned long __init free_low_memory_core_early(void)
 	return count;
 }
 
-static void reset_node_lowmem_managed_pages(pg_data_t *pgdat)
+static int reset_managed_pages_done __initdata;
+
+static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
 {
 	struct zone *z;
 
-	/*
-	 * In free_area_init_core(), highmem zone's managed_pages is set to
-	 * present_pages, and bootmem allocator doesn't allocate from highmem
-	 * zones. So there's no need to recalculate managed_pages because all
-	 * highmem pages will be managed by the buddy system. Here highmem
-	 * zone also includes highmem movable zone.
-	 */
+	if (reset_managed_pages_done)
+		return;
 	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
-		if (!is_highmem(z))
-			z->managed_pages = 0;
+		z->managed_pages = 0;
+}
+
+void __init reset_all_zones_managed_pages(void)
+{
+	struct pglist_data *pgdat;
+
+	for_each_online_pgdat(pgdat)
+		reset_node_managed_pages(pgdat);
+	reset_managed_pages_done = 1;
 }
 
 /**
@@ -160,17 +165,19 @@ static void reset_node_lowmem_managed_pages(pg_data_t *pgdat)
  */
 unsigned long __init free_all_bootmem(void)
 {
-	struct pglist_data *pgdat;
+	unsigned long pages;
 
-	for_each_online_pgdat(pgdat)
-		reset_node_lowmem_managed_pages(pgdat);
+	reset_all_zones_managed_pages();
 
 	/*
 	 * We need to use MAX_NUMNODES instead of NODE_DATA(0)->node_id
 	 *  because in some case like Node0 doesn't have RAM installed
 	 *  low ram will be on Node1
 	 */
-	return free_low_memory_core_early();
+	pages = free_low_memory_core_early();
+	totalram_pages += pages;
+
+	return pages;
 }
 
 /**
diff --git a/mm/nommu.c b/mm/nommu.c
index 298884dcd6e..ecd1f158548 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -56,7 +56,6 @@
 void *high_memory;
 struct page *mem_map;
 unsigned long max_mapnr;
-unsigned long num_physpages;
 unsigned long highest_memmap_pfn;
 struct percpu_counter vm_committed_as;
 int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
@@ -85,7 +84,6 @@ unsigned long vm_memory_committed(void)
 EXPORT_SYMBOL_GPL(vm_memory_committed);
 
 EXPORT_SYMBOL(mem_map);
-EXPORT_SYMBOL(num_physpages);
 
 /* list of mapped, potentially shareable regions */
 static struct kmem_cache *vm_region_jar;
@@ -282,6 +280,10 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
 
 long vread(char *buf, char *addr, unsigned long count)
 {
+	/* Don't allow overflow */
+	if ((unsigned long) buf + count < count)
+		count = -(unsigned long) buf;
+
 	memcpy(buf, addr, count);
 	return count;
 }
@@ -1869,10 +1871,6 @@ unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr,
 	return -ENOMEM;
 }
 
-void arch_unmap_area(struct mm_struct *mm, unsigned long addr)
-{
-}
-
 void unmap_mapping_range(struct address_space *mapping,
 			 loff_t const holebegin, loff_t const holelen,
 			 int even_cows)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c3edb624fcc..b100255dedd 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -61,10 +61,14 @@
 #include <linux/hugetlb.h>
 #include <linux/sched/rt.h>
 
+#include <asm/sections.h>
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
 #include "internal.h"
 
+/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
+static DEFINE_MUTEX(pcp_batch_high_lock);
+
 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
 DEFINE_PER_CPU(int, numa_node);
 EXPORT_PER_CPU_SYMBOL(numa_node);
@@ -100,6 +104,9 @@ nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
 };
 EXPORT_SYMBOL(node_states);
 
+/* Protect totalram_pages and zone->managed_pages */
+static DEFINE_SPINLOCK(managed_page_count_lock);
+
 unsigned long totalram_pages __read_mostly;
 unsigned long totalreserve_pages __read_mostly;
 /*
@@ -197,6 +204,7 @@ static char * const zone_names[MAX_NR_ZONES] = {
 };
 
 int min_free_kbytes = 1024;
+int user_min_free_kbytes;
 
 static unsigned long __meminitdata nr_kernel_pages;
 static unsigned long __meminitdata nr_all_pages;
@@ -739,14 +747,7 @@ static void __free_pages_ok(struct page *page, unsigned int order)
 	local_irq_restore(flags);
 }
 
-/*
- * Read access to zone->managed_pages is safe because it's unsigned long,
- * but we still need to serialize writers. Currently all callers of
- * __free_pages_bootmem() except put_page_bootmem() should only be used
- * at boot time. So for shorter boot time, we shift the burden to
- * put_page_bootmem() to serialize writers.
- */
-void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
+void __init __free_pages_bootmem(struct page *page, unsigned int order)
 {
 	unsigned int nr_pages = 1 << order;
 	unsigned int loop;
@@ -781,11 +782,7 @@ void __init init_cma_reserved_pageblock(struct page *page)
 	set_page_refcounted(page);
 	set_pageblock_migratetype(page, MIGRATE_CMA);
 	__free_pages(page, pageblock_order);
-	totalram_pages += pageblock_nr_pages;
-#ifdef CONFIG_HIGHMEM
-	if (PageHighMem(page))
-		totalhigh_pages += pageblock_nr_pages;
-#endif
+	adjust_managed_page_count(page, pageblock_nr_pages);
 }
 #endif
 
@@ -1050,7 +1047,7 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
 			 * MIGRATE_CMA areas.
 			 */
 			if (!is_migrate_cma(migratetype) &&
-			    (unlikely(current_order >= pageblock_order / 2) ||
+			    (current_order >= pageblock_order / 2 ||
 			     start_migratetype == MIGRATE_RECLAIMABLE ||
 			     page_group_by_mobility_disabled)) {
 				int pages;
@@ -1179,10 +1176,12 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
 {
 	unsigned long flags;
 	int to_drain;
+	unsigned long batch;
 
 	local_irq_save(flags);
-	if (pcp->count >= pcp->batch)
-		to_drain = pcp->batch;
+	batch = ACCESS_ONCE(pcp->batch);
+	if (pcp->count >= batch)
+		to_drain = batch;
 	else
 		to_drain = pcp->count;
 	if (to_drain > 0) {
@@ -1350,8 +1349,9 @@ void free_hot_cold_page(struct page *page, int cold)
 		list_add(&page->lru, &pcp->lists[migratetype]);
 	pcp->count++;
 	if (pcp->count >= pcp->high) {
-		free_pcppages_bulk(zone, pcp->batch, pcp);
-		pcp->count -= pcp->batch;
+		unsigned long batch = ACCESS_ONCE(pcp->batch);
+		free_pcppages_bulk(zone, batch, pcp);
+		pcp->count -= batch;
 	}
 
 out:
@@ -2839,7 +2839,7 @@ EXPORT_SYMBOL(free_pages_exact);
  * nr_free_zone_pages() counts the number of counts pages which are beyond the
  * high watermark within all zones at or below a given zone index.  For each
  * zone, the number of pages is calculated as:
- *     present_pages - high_pages
+ *     managed_pages - high_pages
  */
 static unsigned long nr_free_zone_pages(int offset)
 {
@@ -2906,9 +2906,13 @@ EXPORT_SYMBOL(si_meminfo);
 #ifdef CONFIG_NUMA
 void si_meminfo_node(struct sysinfo *val, int nid)
 {
+	int zone_type;		/* needs to be signed */
+	unsigned long managed_pages = 0;
 	pg_data_t *pgdat = NODE_DATA(nid);
 
-	val->totalram = pgdat->node_present_pages;
+	for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
+		managed_pages += pgdat->node_zones[zone_type].managed_pages;
+	val->totalram = managed_pages;
 	val->freeram = node_page_state(nid, NR_FREE_PAGES);
 #ifdef CONFIG_HIGHMEM
 	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
@@ -3150,12 +3154,10 @@ static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
  * Add all populated zones of a node to the zonelist.
  */
 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
-				int nr_zones, enum zone_type zone_type)
+				int nr_zones)
 {
 	struct zone *zone;
-
-	BUG_ON(zone_type >= MAX_NR_ZONES);
-	zone_type++;
+	enum zone_type zone_type = MAX_NR_ZONES;
 
 	do {
 		zone_type--;
@@ -3165,8 +3167,8 @@ static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
 				&zonelist->_zonerefs[nr_zones++]);
 			check_highest_zone(zone_type);
 		}
-
 	} while (zone_type);
+
 	return nr_zones;
 }
 
@@ -3250,18 +3252,25 @@ int numa_zonelist_order_handler(ctl_table *table, int write,
 	static DEFINE_MUTEX(zl_order_mutex);
 
 	mutex_lock(&zl_order_mutex);
-	if (write)
-		strcpy(saved_string, (char*)table->data);
+	if (write) {
+		if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
+			ret = -EINVAL;
+			goto out;
+		}
+		strcpy(saved_string, (char *)table->data);
+	}
 	ret = proc_dostring(table, write, buffer, length, ppos);
 	if (ret)
 		goto out;
 	if (write) {
 		int oldval = user_zonelist_order;
-		if (__parse_numa_zonelist_order((char*)table->data)) {
+
+		ret = __parse_numa_zonelist_order((char *)table->data);
+		if (ret) {
 			/*
 			 * bogus value.  restore saved string
 			 */
-			strncpy((char*)table->data, saved_string,
+			strncpy((char *)table->data, saved_string,
 				NUMA_ZONELIST_ORDER_LEN);
 			user_zonelist_order = oldval;
 		} else if (oldval != user_zonelist_order) {
@@ -3353,8 +3362,7 @@ static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
 	zonelist = &pgdat->node_zonelists[0];
 	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
 		;
-	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
-							MAX_NR_ZONES - 1);
+	j = build_zonelists_node(NODE_DATA(node), zonelist, j);
 	zonelist->_zonerefs[j].zone = NULL;
 	zonelist->_zonerefs[j].zone_idx = 0;
 }
@@ -3368,7 +3376,7 @@ static void build_thisnode_zonelists(pg_data_t *pgdat)
 	struct zonelist *zonelist;
 
 	zonelist = &pgdat->node_zonelists[1];
-	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
+	j = build_zonelists_node(pgdat, zonelist, 0);
 	zonelist->_zonerefs[j].zone = NULL;
 	zonelist->_zonerefs[j].zone_idx = 0;
 }
@@ -3425,8 +3433,8 @@ static int default_zonelist_order(void)
 			z = &NODE_DATA(nid)->node_zones[zone_type];
 			if (populated_zone(z)) {
 				if (zone_type < ZONE_NORMAL)
-					low_kmem_size += z->present_pages;
-				total_size += z->present_pages;
+					low_kmem_size += z->managed_pages;
+				total_size += z->managed_pages;
 			} else if (zone_type == ZONE_NORMAL) {
 				/*
 				 * If any node has only lowmem, then node order
@@ -3576,7 +3584,7 @@ static void build_zonelists(pg_data_t *pgdat)
 	local_node = pgdat->node_id;
 
 	zonelist = &pgdat->node_zonelists[0];
-	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
+	j = build_zonelists_node(pgdat, zonelist, 0);
 
 	/*
 	 * Now we build the zonelist so that it contains the zones
@@ -3589,14 +3597,12 @@ static void build_zonelists(pg_data_t *pgdat)
 	for (node = local_node + 1; node < MAX_NUMNODES; node++) {
 		if (!node_online(node))
 			continue;
-		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
-							MAX_NR_ZONES - 1);
+		j = build_zonelists_node(NODE_DATA(node), zonelist, j);
 	}
 	for (node = 0; node < local_node; node++) {
 		if (!node_online(node))
 			continue;
-		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
-							MAX_NR_ZONES - 1);
+		j = build_zonelists_node(NODE_DATA(node), zonelist, j);
 	}
 
 	zonelist->_zonerefs[j].zone = NULL;
@@ -3705,12 +3711,12 @@ void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
 		mminit_verify_zonelist();
 		cpuset_init_current_mems_allowed();
 	} else {
-		/* we have to stop all cpus to guarantee there is no user
-		   of zonelist */
 #ifdef CONFIG_MEMORY_HOTPLUG
 		if (zone)
 			setup_zone_pageset(zone);
 #endif
+		/* we have to stop all cpus to guarantee there is no user
+		   of zonelist */
 		stop_machine(__build_all_zonelists, pgdat, NULL);
 		/* cpuset refresh routine should be here */
 	}
@@ -4032,7 +4038,40 @@ static int __meminit zone_batchsize(struct zone *zone)
 #endif
 }
 
-static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+/*
+ * pcp->high and pcp->batch values are related and dependent on one another:
+ * ->batch must never be higher then ->high.
+ * The following function updates them in a safe manner without read side
+ * locking.
+ *
+ * Any new users of pcp->batch and pcp->high should ensure they can cope with
+ * those fields changing asynchronously (acording the the above rule).
+ *
+ * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
+ * outside of boot time (or some other assurance that no concurrent updaters
+ * exist).
+ */
+static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
+		unsigned long batch)
+{
+       /* start with a fail safe value for batch */
+	pcp->batch = 1;
+	smp_wmb();
+
+       /* Update high, then batch, in order */
+	pcp->high = high;
+	smp_wmb();
+
+	pcp->batch = batch;
+}
+
+/* a companion to pageset_set_high() */
+static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
+{
+	pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
+}
+
+static void pageset_init(struct per_cpu_pageset *p)
 {
 	struct per_cpu_pages *pcp;
 	int migratetype;
@@ -4041,45 +4080,55 @@ static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
 
 	pcp = &p->pcp;
 	pcp->count = 0;
-	pcp->high = 6 * batch;
-	pcp->batch = max(1UL, 1 * batch);
 	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
 		INIT_LIST_HEAD(&pcp->lists[migratetype]);
 }
 
+static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+{
+	pageset_init(p);
+	pageset_set_batch(p, batch);
+}
+
 /*
- * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
+ * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
  * to the value high for the pageset p.
  */
-
-static void setup_pagelist_highmark(struct per_cpu_pageset *p,
+static void pageset_set_high(struct per_cpu_pageset *p,
 				unsigned long high)
 {
-	struct per_cpu_pages *pcp;
+	unsigned long batch = max(1UL, high / 4);
+	if ((high / 4) > (PAGE_SHIFT * 8))
+		batch = PAGE_SHIFT * 8;
 
-	pcp = &p->pcp;
-	pcp->high = high;
-	pcp->batch = max(1UL, high/4);
-	if ((high/4) > (PAGE_SHIFT * 8))
-		pcp->batch = PAGE_SHIFT * 8;
+	pageset_update(&p->pcp, high, batch);
 }
 
-static void __meminit setup_zone_pageset(struct zone *zone)
+static void __meminit pageset_set_high_and_batch(struct zone *zone,
+		struct per_cpu_pageset *pcp)
 {
-	int cpu;
-
-	zone->pageset = alloc_percpu(struct per_cpu_pageset);
+	if (percpu_pagelist_fraction)
+		pageset_set_high(pcp,
+			(zone->managed_pages /
+				percpu_pagelist_fraction));
+	else
+		pageset_set_batch(pcp, zone_batchsize(zone));
+}
 
-	for_each_possible_cpu(cpu) {
-		struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
+static void __meminit zone_pageset_init(struct zone *zone, int cpu)
+{
+	struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
 
-		setup_pageset(pcp, zone_batchsize(zone));
+	pageset_init(pcp);
+	pageset_set_high_and_batch(zone, pcp);
+}
 
-		if (percpu_pagelist_fraction)
-			setup_pagelist_highmark(pcp,
-				(zone->managed_pages /
-					percpu_pagelist_fraction));
-	}
+static void __meminit setup_zone_pageset(struct zone *zone)
+{
+	int cpu;
+	zone->pageset = alloc_percpu(struct per_cpu_pageset);
+	for_each_possible_cpu(cpu)
+		zone_pageset_init(zone, cpu);
 }
 
 /*
@@ -4368,13 +4417,13 @@ static void __meminit adjust_zone_range_for_zone_movable(int nid,
  */
 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
 					unsigned long zone_type,
+					unsigned long node_start_pfn,
+					unsigned long node_end_pfn,
 					unsigned long *ignored)
 {
-	unsigned long node_start_pfn, node_end_pfn;
 	unsigned long zone_start_pfn, zone_end_pfn;
 
-	/* Get the start and end of the node and zone */
-	get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
+	/* Get the start and end of the zone */
 	zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
 	zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
 	adjust_zone_range_for_zone_movable(nid, zone_type,
@@ -4429,14 +4478,14 @@ unsigned long __init absent_pages_in_range(unsigned long start_pfn,
 /* Return the number of page frames in holes in a zone on a node */
 static unsigned long __meminit zone_absent_pages_in_node(int nid,
 					unsigned long zone_type,
+					unsigned long node_start_pfn,
+					unsigned long node_end_pfn,
 					unsigned long *ignored)
 {
 	unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
 	unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
-	unsigned long node_start_pfn, node_end_pfn;
 	unsigned long zone_start_pfn, zone_end_pfn;
 
-	get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
 	zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
 	zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
 
@@ -4449,6 +4498,8 @@ static unsigned long __meminit zone_absent_pages_in_node(int nid,
 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
 					unsigned long zone_type,
+					unsigned long node_start_pfn,
+					unsigned long node_end_pfn,
 					unsigned long *zones_size)
 {
 	return zones_size[zone_type];
@@ -4456,6 +4507,8 @@ static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
 
 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
 						unsigned long zone_type,
+						unsigned long node_start_pfn,
+						unsigned long node_end_pfn,
 						unsigned long *zholes_size)
 {
 	if (!zholes_size)
@@ -4467,21 +4520,27 @@ static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
 
 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
-		unsigned long *zones_size, unsigned long *zholes_size)
+						unsigned long node_start_pfn,
+						unsigned long node_end_pfn,
+						unsigned long *zones_size,
+						unsigned long *zholes_size)
 {
 	unsigned long realtotalpages, totalpages = 0;
 	enum zone_type i;
 
 	for (i = 0; i < MAX_NR_ZONES; i++)
 		totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
-								zones_size);
+							 node_start_pfn,
+							 node_end_pfn,
+							 zones_size);
 	pgdat->node_spanned_pages = totalpages;
 
 	realtotalpages = totalpages;
 	for (i = 0; i < MAX_NR_ZONES; i++)
 		realtotalpages -=
 			zone_absent_pages_in_node(pgdat->node_id, i,
-								zholes_size);
+						  node_start_pfn, node_end_pfn,
+						  zholes_size);
 	pgdat->node_present_pages = realtotalpages;
 	printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
 							realtotalpages);
@@ -4590,6 +4649,7 @@ static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
  * NOTE: pgdat should get zeroed by caller.
  */
 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
+		unsigned long node_start_pfn, unsigned long node_end_pfn,
 		unsigned long *zones_size, unsigned long *zholes_size)
 {
 	enum zone_type j;
@@ -4611,8 +4671,11 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
 		struct zone *zone = pgdat->node_zones + j;
 		unsigned long size, realsize, freesize, memmap_pages;
 
-		size = zone_spanned_pages_in_node(nid, j, zones_size);
+		size = zone_spanned_pages_in_node(nid, j, node_start_pfn,
+						  node_end_pfn, zones_size);
 		realsize = freesize = size - zone_absent_pages_in_node(nid, j,
+								node_start_pfn,
+								node_end_pfn,
 								zholes_size);
 
 		/*
@@ -4726,6 +4789,8 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
 		unsigned long node_start_pfn, unsigned long *zholes_size)
 {
 	pg_data_t *pgdat = NODE_DATA(nid);
+	unsigned long start_pfn = 0;
+	unsigned long end_pfn = 0;
 
 	/* pg_data_t should be reset to zero when it's allocated */
 	WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
@@ -4733,7 +4798,11 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
 	pgdat->node_id = nid;
 	pgdat->node_start_pfn = node_start_pfn;
 	init_zone_allows_reclaim(nid);
-	calculate_node_totalpages(pgdat, zones_size, zholes_size);
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+	get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
+#endif
+	calculate_node_totalpages(pgdat, start_pfn, end_pfn,
+				  zones_size, zholes_size);
 
 	alloc_node_mem_map(pgdat);
 #ifdef CONFIG_FLAT_NODE_MEM_MAP
@@ -4742,7 +4811,8 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
 		(unsigned long)pgdat->node_mem_map);
 #endif
 
-	free_area_init_core(pgdat, zones_size, zholes_size);
+	free_area_init_core(pgdat, start_pfn, end_pfn,
+			    zones_size, zholes_size);
 }
 
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
@@ -5150,35 +5220,101 @@ early_param("movablecore", cmdline_parse_movablecore);
 
 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
 
-unsigned long free_reserved_area(unsigned long start, unsigned long end,
-				 int poison, char *s)
+void adjust_managed_page_count(struct page *page, long count)
 {
-	unsigned long pages, pos;
+	spin_lock(&managed_page_count_lock);
+	page_zone(page)->managed_pages += count;
+	totalram_pages += count;
+#ifdef CONFIG_HIGHMEM
+	if (PageHighMem(page))
+		totalhigh_pages += count;
+#endif
+	spin_unlock(&managed_page_count_lock);
+}
+EXPORT_SYMBOL(adjust_managed_page_count);
 
-	pos = start = PAGE_ALIGN(start);
-	end &= PAGE_MASK;
-	for (pages = 0; pos < end; pos += PAGE_SIZE, pages++) {
-		if (poison)
-			memset((void *)pos, poison, PAGE_SIZE);
-		free_reserved_page(virt_to_page((void *)pos));
+unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
+{
+	void *pos;
+	unsigned long pages = 0;
+
+	start = (void *)PAGE_ALIGN((unsigned long)start);
+	end = (void *)((unsigned long)end & PAGE_MASK);
+	for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
+		if ((unsigned int)poison <= 0xFF)
+			memset(pos, poison, PAGE_SIZE);
+		free_reserved_page(virt_to_page(pos));
 	}
 
 	if (pages && s)
-		pr_info("Freeing %s memory: %ldK (%lx - %lx)\n",
+		pr_info("Freeing %s memory: %ldK (%p - %p)\n",
 			s, pages << (PAGE_SHIFT - 10), start, end);
 
 	return pages;
 }
+EXPORT_SYMBOL(free_reserved_area);
 
 #ifdef	CONFIG_HIGHMEM
 void free_highmem_page(struct page *page)
 {
 	__free_reserved_page(page);
 	totalram_pages++;
+	page_zone(page)->managed_pages++;
 	totalhigh_pages++;
 }
 #endif
 
+
+void __init mem_init_print_info(const char *str)
+{
+	unsigned long physpages, codesize, datasize, rosize, bss_size;
+	unsigned long init_code_size, init_data_size;
+
+	physpages = get_num_physpages();
+	codesize = _etext - _stext;
+	datasize = _edata - _sdata;
+	rosize = __end_rodata - __start_rodata;
+	bss_size = __bss_stop - __bss_start;
+	init_data_size = __init_end - __init_begin;
+	init_code_size = _einittext - _sinittext;
+
+	/*
+	 * Detect special cases and adjust section sizes accordingly:
+	 * 1) .init.* may be embedded into .data sections
+	 * 2) .init.text.* may be out of [__init_begin, __init_end],
+	 *    please refer to arch/tile/kernel/vmlinux.lds.S.
+	 * 3) .rodata.* may be embedded into .text or .data sections.
+	 */
+#define adj_init_size(start, end, size, pos, adj) \
+	if (start <= pos && pos < end && size > adj) \
+		size -= adj;
+
+	adj_init_size(__init_begin, __init_end, init_data_size,
+		     _sinittext, init_code_size);
+	adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
+	adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
+	adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
+	adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
+
+#undef	adj_init_size
+
+	printk("Memory: %luK/%luK available "
+	       "(%luK kernel code, %luK rwdata, %luK rodata, "
+	       "%luK init, %luK bss, %luK reserved"
+#ifdef	CONFIG_HIGHMEM
+	       ", %luK highmem"
+#endif
+	       "%s%s)\n",
+	       nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
+	       codesize >> 10, datasize >> 10, rosize >> 10,
+	       (init_data_size + init_code_size) >> 10, bss_size >> 10,
+	       (physpages - totalram_pages) << (PAGE_SHIFT-10),
+#ifdef	CONFIG_HIGHMEM
+	       totalhigh_pages << (PAGE_SHIFT-10),
+#endif
+	       str ? ", " : "", str ? str : "");
+}
+
 /**
  * set_dma_reserve - set the specified number of pages reserved in the first zone
  * @new_dma_reserve: The number of pages to mark reserved
@@ -5454,14 +5590,21 @@ static void __meminit setup_per_zone_inactive_ratio(void)
 int __meminit init_per_zone_wmark_min(void)
 {
 	unsigned long lowmem_kbytes;
+	int new_min_free_kbytes;
 
 	lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
-
-	min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
-	if (min_free_kbytes < 128)
-		min_free_kbytes = 128;
-	if (min_free_kbytes > 65536)
-		min_free_kbytes = 65536;
+	new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
+
+	if (new_min_free_kbytes > user_min_free_kbytes) {
+		min_free_kbytes = new_min_free_kbytes;
+		if (min_free_kbytes < 128)
+			min_free_kbytes = 128;
+		if (min_free_kbytes > 65536)
+			min_free_kbytes = 65536;
+	} else {
+		pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
+				new_min_free_kbytes, user_min_free_kbytes);
+	}
 	setup_per_zone_wmarks();
 	refresh_zone_stat_thresholds();
 	setup_per_zone_lowmem_reserve();
@@ -5479,8 +5622,10 @@ int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
 	void __user *buffer, size_t *length, loff_t *ppos)
 {
 	proc_dointvec(table, write, buffer, length, ppos);
-	if (write)
+	if (write) {
+		user_min_free_kbytes = min_free_kbytes;
 		setup_per_zone_wmarks();
+	}
 	return 0;
 }
 
@@ -5540,7 +5685,6 @@ int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
  * cpu.  It is the fraction of total pages in each zone that a hot per cpu pagelist
  * can have before it gets flushed back to buddy allocator.
  */
-
 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
 	void __user *buffer, size_t *length, loff_t *ppos)
 {
@@ -5551,14 +5695,16 @@ int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
 	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
 	if (!write || (ret < 0))
 		return ret;
+
+	mutex_lock(&pcp_batch_high_lock);
 	for_each_populated_zone(zone) {
-		for_each_possible_cpu(cpu) {
-			unsigned long  high;
-			high = zone->managed_pages / percpu_pagelist_fraction;
-			setup_pagelist_highmark(
-				per_cpu_ptr(zone->pageset, cpu), high);
-		}
+		unsigned long  high;
+		high = zone->managed_pages / percpu_pagelist_fraction;
+		for_each_possible_cpu(cpu)
+			pageset_set_high(per_cpu_ptr(zone->pageset, cpu),
+					 high);
 	}
+	mutex_unlock(&pcp_batch_high_lock);
 	return 0;
 }
 
@@ -6047,32 +6193,18 @@ void free_contig_range(unsigned long pfn, unsigned nr_pages)
 #endif
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-static int __meminit __zone_pcp_update(void *data)
-{
-	struct zone *zone = data;
-	int cpu;
-	unsigned long batch = zone_batchsize(zone), flags;
-
-	for_each_possible_cpu(cpu) {
-		struct per_cpu_pageset *pset;
-		struct per_cpu_pages *pcp;
-
-		pset = per_cpu_ptr(zone->pageset, cpu);
-		pcp = &pset->pcp;
-
-		local_irq_save(flags);
-		if (pcp->count > 0)
-			free_pcppages_bulk(zone, pcp->count, pcp);
-		drain_zonestat(zone, pset);
-		setup_pageset(pset, batch);
-		local_irq_restore(flags);
-	}
-	return 0;
-}
-
+/*
+ * The zone indicated has a new number of managed_pages; batch sizes and percpu
+ * page high values need to be recalulated.
+ */
 void __meminit zone_pcp_update(struct zone *zone)
 {
-	stop_machine(__zone_pcp_update, zone, NULL);
+	unsigned cpu;
+	mutex_lock(&pcp_batch_high_lock);
+	for_each_possible_cpu(cpu)
+		pageset_set_high_and_batch(zone,
+				per_cpu_ptr(zone->pageset, cpu));
+	mutex_unlock(&pcp_batch_high_lock);
 }
 #endif
 
@@ -6142,6 +6274,10 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
 		list_del(&page->lru);
 		rmv_page_order(page);
 		zone->free_area[order].nr_free--;
+#ifdef CONFIG_HIGHMEM
+		if (PageHighMem(page))
+			totalhigh_pages -= 1 << order;
+#endif
 		for (i = 0; i < (1 << order); i++)
 			SetPageReserved((page+i));
 		pfn += (1 << order);
diff --git a/mm/page_io.c b/mm/page_io.c
index a8a3ef45fed..ba05b64e5d8 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -21,6 +21,7 @@
 #include <linux/writeback.h>
 #include <linux/frontswap.h>
 #include <linux/aio.h>
+#include <linux/blkdev.h>
 #include <asm/pgtable.h>
 
 static struct bio *get_swap_bio(gfp_t gfp_flags,
@@ -80,9 +81,54 @@ void end_swap_bio_read(struct bio *bio, int err)
 				imajor(bio->bi_bdev->bd_inode),
 				iminor(bio->bi_bdev->bd_inode),
 				(unsigned long long)bio->bi_sector);
-	} else {
-		SetPageUptodate(page);
+		goto out;
 	}
+
+	SetPageUptodate(page);
+
+	/*
+	 * There is no guarantee that the page is in swap cache - the software
+	 * suspend code (at least) uses end_swap_bio_read() against a non-
+	 * swapcache page.  So we must check PG_swapcache before proceeding with
+	 * this optimization.
+	 */
+	if (likely(PageSwapCache(page))) {
+		struct swap_info_struct *sis;
+
+		sis = page_swap_info(page);
+		if (sis->flags & SWP_BLKDEV) {
+			/*
+			 * The swap subsystem performs lazy swap slot freeing,
+			 * expecting that the page will be swapped out again.
+			 * So we can avoid an unnecessary write if the page
+			 * isn't redirtied.
+			 * This is good for real swap storage because we can
+			 * reduce unnecessary I/O and enhance wear-leveling
+			 * if an SSD is used as the as swap device.
+			 * But if in-memory swap device (eg zram) is used,
+			 * this causes a duplicated copy between uncompressed
+			 * data in VM-owned memory and compressed data in
+			 * zram-owned memory.  So let's free zram-owned memory
+			 * and make the VM-owned decompressed page *dirty*,
+			 * so the page should be swapped out somewhere again if
+			 * we again wish to reclaim it.
+			 */
+			struct gendisk *disk = sis->bdev->bd_disk;
+			if (disk->fops->swap_slot_free_notify) {
+				swp_entry_t entry;
+				unsigned long offset;
+
+				entry.val = page_private(page);
+				offset = swp_offset(entry);
+
+				SetPageDirty(page);
+				disk->fops->swap_slot_free_notify(sis->bdev,
+						offset);
+			}
+		}
+	}
+
+out:
 	unlock_page(page);
 	bio_put(bio);
 }
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 0c8323fe6c8..e1a6e4fab01 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -124,7 +124,8 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
 
 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				pgtable_t pgtable)
 {
 	assert_spin_locked(&mm->page_table_lock);
 
@@ -141,7 +142,7 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 /* no "address" argument so destroys page coloring of some arch */
-pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 {
 	pgtable_t pgtable;
 
diff --git a/mm/rmap.c b/mm/rmap.c
index 6280da86b5d..cd356df4f71 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -720,7 +720,7 @@ int page_referenced_one(struct page *page, struct vm_area_struct *vma,
 			 * mapping is already gone, the unmap path will have
 			 * set PG_referenced or activated the page.
 			 */
-			if (likely(!VM_SequentialReadHint(vma)))
+			if (likely(!(vma->vm_flags & VM_SEQ_READ)))
 				referenced++;
 		}
 		pte_unmap_unlock(pte, ptl);
@@ -1093,9 +1093,10 @@ void page_add_new_anon_rmap(struct page *page,
 	else
 		__inc_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
 	__page_set_anon_rmap(page, vma, address, 1);
-	if (!mlocked_vma_newpage(vma, page))
-		lru_cache_add_lru(page, LRU_ACTIVE_ANON);
-	else
+	if (!mlocked_vma_newpage(vma, page)) {
+		SetPageActive(page);
+		lru_cache_add(page);
+	} else
 		add_page_to_unevictable_list(page);
 }
 
diff --git a/mm/shmem.c b/mm/shmem.c
index 118dfa4952f..a87990cf9f9 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1936,6 +1936,13 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
 
 	inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
 	if (inode) {
+#ifdef CONFIG_TMPFS_POSIX_ACL
+		error = generic_acl_init(inode, dir);
+		if (error) {
+			iput(inode);
+			return error;
+		}
+#endif
 		error = security_inode_init_security(inode, dir,
 						     &dentry->d_name,
 						     shmem_initxattrs, NULL);
@@ -1945,15 +1952,8 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
 				return error;
 			}
 		}
-#ifdef CONFIG_TMPFS_POSIX_ACL
-		error = generic_acl_init(inode, dir);
-		if (error) {
-			iput(inode);
-			return error;
-		}
-#else
+
 		error = 0;
-#endif
 		dir->i_size += BOGO_DIRENT_SIZE;
 		dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 		d_instantiate(dentry, inode);
diff --git a/mm/slab.c b/mm/slab.c
index 8ccd296c6d9..35cb0c86150 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -565,7 +565,7 @@ static void init_node_lock_keys(int q)
 	if (slab_state < UP)
 		return;
 
-	for (i = 1; i < PAGE_SHIFT + MAX_ORDER; i++) {
+	for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) {
 		struct kmem_cache_node *n;
 		struct kmem_cache *cache = kmalloc_caches[i];
 
@@ -1180,6 +1180,12 @@ static int init_cache_node_node(int node)
 	return 0;
 }
 
+static inline int slabs_tofree(struct kmem_cache *cachep,
+						struct kmem_cache_node *n)
+{
+	return (n->free_objects + cachep->num - 1) / cachep->num;
+}
+
 static void __cpuinit cpuup_canceled(long cpu)
 {
 	struct kmem_cache *cachep;
@@ -1241,7 +1247,7 @@ free_array_cache:
 		n = cachep->node[node];
 		if (!n)
 			continue;
-		drain_freelist(cachep, n, n->free_objects);
+		drain_freelist(cachep, n, slabs_tofree(cachep, n));
 	}
 }
 
@@ -1408,7 +1414,7 @@ static int __meminit drain_cache_node_node(int node)
 		if (!n)
 			continue;
 
-		drain_freelist(cachep, n, n->free_objects);
+		drain_freelist(cachep, n, slabs_tofree(cachep, n));
 
 		if (!list_empty(&n->slabs_full) ||
 		    !list_empty(&n->slabs_partial)) {
@@ -2532,7 +2538,7 @@ static int __cache_shrink(struct kmem_cache *cachep)
 		if (!n)
 			continue;
 
-		drain_freelist(cachep, n, n->free_objects);
+		drain_freelist(cachep, n, slabs_tofree(cachep, n));
 
 		ret += !list_empty(&n->slabs_full) ||
 			!list_empty(&n->slabs_partial);
@@ -3338,18 +3344,6 @@ done:
 	return obj;
 }
 
-/**
- * kmem_cache_alloc_node - Allocate an object on the specified node
- * @cachep: The cache to allocate from.
- * @flags: See kmalloc().
- * @nodeid: node number of the target node.
- * @caller: return address of caller, used for debug information
- *
- * Identical to kmem_cache_alloc but it will allocate memory on the given
- * node, which can improve the performance for cpu bound structures.
- *
- * Fallback to other node is possible if __GFP_THISNODE is not set.
- */
 static __always_inline void *
 slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
 		   unsigned long caller)
@@ -3643,6 +3637,17 @@ EXPORT_SYMBOL(kmem_cache_alloc_trace);
 #endif
 
 #ifdef CONFIG_NUMA
+/**
+ * kmem_cache_alloc_node - Allocate an object on the specified node
+ * @cachep: The cache to allocate from.
+ * @flags: See kmalloc().
+ * @nodeid: node number of the target node.
+ *
+ * Identical to kmem_cache_alloc but it will allocate memory on the given
+ * node, which can improve the performance for cpu bound structures.
+ *
+ * Fallback to other node is possible if __GFP_THISNODE is not set.
+ */
 void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 {
 	void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);
@@ -4431,20 +4436,10 @@ static int leaks_show(struct seq_file *m, void *p)
 	return 0;
 }
 
-static void *s_next(struct seq_file *m, void *p, loff_t *pos)
-{
-	return seq_list_next(p, &slab_caches, pos);
-}
-
-static void s_stop(struct seq_file *m, void *p)
-{
-	mutex_unlock(&slab_mutex);
-}
-
 static const struct seq_operations slabstats_op = {
 	.start = leaks_start,
-	.next = s_next,
-	.stop = s_stop,
+	.next = slab_next,
+	.stop = slab_stop,
 	.show = leaks_show,
 };
 
diff --git a/mm/slab.h b/mm/slab.h
index f96b49e4704..620ceeddbe1 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -271,3 +271,6 @@ struct kmem_cache_node {
 #endif
 
 };
+
+void *slab_next(struct seq_file *m, void *p, loff_t *pos);
+void slab_stop(struct seq_file *m, void *p);
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 2d414508e9e..538bade6df7 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -497,6 +497,13 @@ void __init create_kmalloc_caches(unsigned long flags)
 
 
 #ifdef CONFIG_SLABINFO
+
+#ifdef CONFIG_SLAB
+#define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
+#else
+#define SLABINFO_RIGHTS S_IRUSR
+#endif
+
 void print_slabinfo_header(struct seq_file *m)
 {
 	/*
@@ -531,12 +538,12 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 	return seq_list_start(&slab_caches, *pos);
 }
 
-static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+void *slab_next(struct seq_file *m, void *p, loff_t *pos)
 {
 	return seq_list_next(p, &slab_caches, pos);
 }
 
-static void s_stop(struct seq_file *m, void *p)
+void slab_stop(struct seq_file *m, void *p)
 {
 	mutex_unlock(&slab_mutex);
 }
@@ -613,8 +620,8 @@ static int s_show(struct seq_file *m, void *p)
  */
 static const struct seq_operations slabinfo_op = {
 	.start = s_start,
-	.next = s_next,
-	.stop = s_stop,
+	.next = slab_next,
+	.stop = slab_stop,
 	.show = s_show,
 };
 
@@ -633,7 +640,8 @@ static const struct file_operations proc_slabinfo_operations = {
 
 static int __init slab_proc_init(void)
 {
-	proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations);
+	proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
+						&proc_slabinfo_operations);
 	return 0;
 }
 module_init(slab_proc_init);
diff --git a/mm/slob.c b/mm/slob.c
index eeed4a05a2e..91bd3f2dd2f 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -122,7 +122,7 @@ static inline void clear_slob_page_free(struct page *sp)
 }
 
 #define SLOB_UNIT sizeof(slob_t)
-#define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT)
+#define SLOB_UNITS(size) DIV_ROUND_UP(size, SLOB_UNIT)
 
 /*
  * struct slob_rcu is inserted at the tail of allocated slob blocks, which
@@ -554,7 +554,7 @@ void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node)
 					    flags, node);
 	}
 
-	if (c->ctor)
+	if (b && c->ctor)
 		c->ctor(b);
 
 	kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags);
diff --git a/mm/slub.c b/mm/slub.c
index 57707f01bcf..3b482c86300 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -123,6 +123,15 @@ static inline int kmem_cache_debug(struct kmem_cache *s)
 #endif
 }
 
+static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
+{
+#ifdef CONFIG_SLUB_CPU_PARTIAL
+	return !kmem_cache_debug(s);
+#else
+	return false;
+#endif
+}
+
 /*
  * Issues still to be resolved:
  *
@@ -1573,7 +1582,8 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
 			put_cpu_partial(s, page, 0);
 			stat(s, CPU_PARTIAL_NODE);
 		}
-		if (kmem_cache_debug(s) || available > s->cpu_partial / 2)
+		if (!kmem_cache_has_cpu_partial(s)
+			|| available > s->cpu_partial / 2)
 			break;
 
 	}
@@ -1884,6 +1894,7 @@ redo:
 static void unfreeze_partials(struct kmem_cache *s,
 		struct kmem_cache_cpu *c)
 {
+#ifdef CONFIG_SLUB_CPU_PARTIAL
 	struct kmem_cache_node *n = NULL, *n2 = NULL;
 	struct page *page, *discard_page = NULL;
 
@@ -1938,6 +1949,7 @@ static void unfreeze_partials(struct kmem_cache *s,
 		discard_slab(s, page);
 		stat(s, FREE_SLAB);
 	}
+#endif
 }
 
 /*
@@ -1951,10 +1963,14 @@ static void unfreeze_partials(struct kmem_cache *s,
  */
 static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
 {
+#ifdef CONFIG_SLUB_CPU_PARTIAL
 	struct page *oldpage;
 	int pages;
 	int pobjects;
 
+	if (!s->cpu_partial)
+		return;
+
 	do {
 		pages = 0;
 		pobjects = 0;
@@ -1987,6 +2003,7 @@ static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
 		page->next = oldpage;
 
 	} while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage);
+#endif
 }
 
 static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
@@ -2358,7 +2375,7 @@ redo:
 
 	object = c->freelist;
 	page = c->page;
-	if (unlikely(!object || !node_match(page, node)))
+	if (unlikely(!object || !page || !node_match(page, node)))
 		object = __slab_alloc(s, gfpflags, node, addr, c);
 
 	else {
@@ -2495,7 +2512,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 		new.inuse--;
 		if ((!new.inuse || !prior) && !was_frozen) {
 
-			if (!kmem_cache_debug(s) && !prior)
+			if (kmem_cache_has_cpu_partial(s) && !prior)
 
 				/*
 				 * Slab was on no list before and will be partially empty
@@ -2550,8 +2567,9 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 	 * Objects left in the slab. If it was not on the partial list before
 	 * then add it.
 	 */
-	if (kmem_cache_debug(s) && unlikely(!prior)) {
-		remove_full(s, page);
+	if (!kmem_cache_has_cpu_partial(s) && unlikely(!prior)) {
+		if (kmem_cache_debug(s))
+			remove_full(s, page);
 		add_partial(n, page, DEACTIVATE_TO_TAIL);
 		stat(s, FREE_ADD_PARTIAL);
 	}
@@ -3059,7 +3077,7 @@ static int kmem_cache_open(struct kmem_cache *s, unsigned long flags)
 	 *    per node list when we run out of per cpu objects. We only fetch 50%
 	 *    to keep some capacity around for frees.
 	 */
-	if (kmem_cache_debug(s))
+	if (!kmem_cache_has_cpu_partial(s))
 		s->cpu_partial = 0;
 	else if (s->size >= PAGE_SIZE)
 		s->cpu_partial = 2;
@@ -4456,7 +4474,7 @@ static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
 	err = strict_strtoul(buf, 10, &objects);
 	if (err)
 		return err;
-	if (objects && kmem_cache_debug(s))
+	if (objects && !kmem_cache_has_cpu_partial(s))
 		return -EINVAL;
 
 	s->cpu_partial = objects;
@@ -5269,7 +5287,6 @@ __initcall(slab_sysfs_init);
 #ifdef CONFIG_SLABINFO
 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
 {
-	unsigned long nr_partials = 0;
 	unsigned long nr_slabs = 0;
 	unsigned long nr_objs = 0;
 	unsigned long nr_free = 0;
@@ -5281,9 +5298,8 @@ void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
 		if (!n)
 			continue;
 
-		nr_partials += n->nr_partial;
-		nr_slabs += atomic_long_read(&n->nr_slabs);
-		nr_objs += atomic_long_read(&n->total_objects);
+		nr_slabs += node_nr_slabs(n);
+		nr_objs += node_nr_objs(n);
 		nr_free += count_partial(n, count_free);
 	}
 
diff --git a/mm/sparse.c b/mm/sparse.c
index 1c91f0d3f6a..308d50331bc 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -79,7 +79,6 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid)
 {
 	unsigned long root = SECTION_NR_TO_ROOT(section_nr);
 	struct mem_section *section;
-	int ret = 0;
 
 	if (mem_section[root])
 		return -EEXIST;
@@ -90,7 +89,7 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid)
 
 	mem_section[root] = section;
 
-	return ret;
+	return 0;
 }
 #else /* !SPARSEMEM_EXTREME */
 static inline int sparse_index_init(unsigned long section_nr, int nid)
@@ -481,6 +480,9 @@ void __init sparse_init(void)
 	struct page **map_map;
 #endif
 
+	/* see include/linux/mmzone.h 'struct mem_section' definition */
+	BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
+
 	/* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
 	set_pageblock_order();
 
@@ -751,6 +753,7 @@ out:
 	return ret;
 }
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
 #ifdef CONFIG_MEMORY_FAILURE
 static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 {
@@ -772,7 +775,6 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 }
 #endif
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static void free_section_usemap(struct page *memmap, unsigned long *usemap)
 {
 	struct page *usemap_page;
diff --git a/mm/swap.c b/mm/swap.c
index dfd7d71d684..4a1d0d2c52f 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -34,10 +34,13 @@
 
 #include "internal.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/pagemap.h>
+
 /* How many pages do we try to swap or page in/out together? */
 int page_cluster;
 
-static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs);
+static DEFINE_PER_CPU(struct pagevec, lru_add_pvec);
 static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
 static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs);
 
@@ -384,6 +387,7 @@ static void __activate_page(struct page *page, struct lruvec *lruvec,
 		SetPageActive(page);
 		lru += LRU_ACTIVE;
 		add_page_to_lru_list(page, lruvec, lru);
+		trace_mm_lru_activate(page, page_to_pfn(page));
 
 		__count_vm_event(PGACTIVATE);
 		update_page_reclaim_stat(lruvec, file, 1);
@@ -428,6 +432,33 @@ void activate_page(struct page *page)
 }
 #endif
 
+static void __lru_cache_activate_page(struct page *page)
+{
+	struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
+	int i;
+
+	/*
+	 * Search backwards on the optimistic assumption that the page being
+	 * activated has just been added to this pagevec. Note that only
+	 * the local pagevec is examined as a !PageLRU page could be in the
+	 * process of being released, reclaimed, migrated or on a remote
+	 * pagevec that is currently being drained. Furthermore, marking
+	 * a remote pagevec's page PageActive potentially hits a race where
+	 * a page is marked PageActive just after it is added to the inactive
+	 * list causing accounting errors and BUG_ON checks to trigger.
+	 */
+	for (i = pagevec_count(pvec) - 1; i >= 0; i--) {
+		struct page *pagevec_page = pvec->pages[i];
+
+		if (pagevec_page == page) {
+			SetPageActive(page);
+			break;
+		}
+	}
+
+	put_cpu_var(lru_add_pvec);
+}
+
 /*
  * Mark a page as having seen activity.
  *
@@ -438,8 +469,18 @@ void activate_page(struct page *page)
 void mark_page_accessed(struct page *page)
 {
 	if (!PageActive(page) && !PageUnevictable(page) &&
-			PageReferenced(page) && PageLRU(page)) {
-		activate_page(page);
+			PageReferenced(page)) {
+
+		/*
+		 * If the page is on the LRU, queue it for activation via
+		 * activate_page_pvecs. Otherwise, assume the page is on a
+		 * pagevec, mark it active and it'll be moved to the active
+		 * LRU on the next drain.
+		 */
+		if (PageLRU(page))
+			activate_page(page);
+		else
+			__lru_cache_activate_page(page);
 		ClearPageReferenced(page);
 	} else if (!PageReferenced(page)) {
 		SetPageReferenced(page);
@@ -448,42 +489,37 @@ void mark_page_accessed(struct page *page)
 EXPORT_SYMBOL(mark_page_accessed);
 
 /*
- * Order of operations is important: flush the pagevec when it's already
- * full, not when adding the last page, to make sure that last page is
- * not added to the LRU directly when passed to this function. Because
- * mark_page_accessed() (called after this when writing) only activates
- * pages that are on the LRU, linear writes in subpage chunks would see
- * every PAGEVEC_SIZE page activated, which is unexpected.
+ * Queue the page for addition to the LRU via pagevec. The decision on whether
+ * to add the page to the [in]active [file|anon] list is deferred until the
+ * pagevec is drained. This gives a chance for the caller of __lru_cache_add()
+ * have the page added to the active list using mark_page_accessed().
  */
-void __lru_cache_add(struct page *page, enum lru_list lru)
+void __lru_cache_add(struct page *page)
 {
-	struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru];
+	struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
 
 	page_cache_get(page);
 	if (!pagevec_space(pvec))
-		__pagevec_lru_add(pvec, lru);
+		__pagevec_lru_add(pvec);
 	pagevec_add(pvec, page);
-	put_cpu_var(lru_add_pvecs);
+	put_cpu_var(lru_add_pvec);
 }
 EXPORT_SYMBOL(__lru_cache_add);
 
 /**
- * lru_cache_add_lru - add a page to a page list
+ * lru_cache_add - add a page to a page list
  * @page: the page to be added to the LRU.
- * @lru: the LRU list to which the page is added.
  */
-void lru_cache_add_lru(struct page *page, enum lru_list lru)
+void lru_cache_add(struct page *page)
 {
 	if (PageActive(page)) {
 		VM_BUG_ON(PageUnevictable(page));
-		ClearPageActive(page);
 	} else if (PageUnevictable(page)) {
 		VM_BUG_ON(PageActive(page));
-		ClearPageUnevictable(page);
 	}
 
-	VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page));
-	__lru_cache_add(page, lru);
+	VM_BUG_ON(PageLRU(page));
+	__lru_cache_add(page);
 }
 
 /**
@@ -583,15 +619,10 @@ static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec,
  */
 void lru_add_drain_cpu(int cpu)
 {
-	struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu);
-	struct pagevec *pvec;
-	int lru;
+	struct pagevec *pvec = &per_cpu(lru_add_pvec, cpu);
 
-	for_each_lru(lru) {
-		pvec = &pvecs[lru - LRU_BASE];
-		if (pagevec_count(pvec))
-			__pagevec_lru_add(pvec, lru);
-	}
+	if (pagevec_count(pvec))
+		__pagevec_lru_add(pvec);
 
 	pvec = &per_cpu(lru_rotate_pvecs, cpu);
 	if (pagevec_count(pvec)) {
@@ -708,6 +739,9 @@ void release_pages(struct page **pages, int nr, int cold)
 			del_page_from_lru_list(page, lruvec, page_off_lru(page));
 		}
 
+		/* Clear Active bit in case of parallel mark_page_accessed */
+		ClearPageActive(page);
+
 		list_add(&page->lru, &pages_to_free);
 	}
 	if (zone)
@@ -795,30 +829,26 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
 static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
 				 void *arg)
 {
-	enum lru_list lru = (enum lru_list)arg;
-	int file = is_file_lru(lru);
-	int active = is_active_lru(lru);
+	int file = page_is_file_cache(page);
+	int active = PageActive(page);
+	enum lru_list lru = page_lru(page);
 
-	VM_BUG_ON(PageActive(page));
 	VM_BUG_ON(PageUnevictable(page));
 	VM_BUG_ON(PageLRU(page));
 
 	SetPageLRU(page);
-	if (active)
-		SetPageActive(page);
 	add_page_to_lru_list(page, lruvec, lru);
 	update_page_reclaim_stat(lruvec, file, active);
+	trace_mm_lru_insertion(page, page_to_pfn(page), lru, trace_pagemap_flags(page));
 }
 
 /*
  * Add the passed pages to the LRU, then drop the caller's refcount
  * on them.  Reinitialises the caller's pagevec.
  */
-void __pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
+void __pagevec_lru_add(struct pagevec *pvec)
 {
-	VM_BUG_ON(is_unevictable_lru(lru));
-
-	pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, (void *)lru);
+	pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, NULL);
 }
 EXPORT_SYMBOL(__pagevec_lru_add);
 
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 746af55b845..36af6eeaa67 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -212,7 +212,7 @@ static unsigned long scan_swap_map(struct swap_info_struct *si,
 			si->cluster_nr = SWAPFILE_CLUSTER - 1;
 			goto checks;
 		}
-		if (si->flags & SWP_DISCARDABLE) {
+		if (si->flags & SWP_PAGE_DISCARD) {
 			/*
 			 * Start range check on racing allocations, in case
 			 * they overlap the cluster we eventually decide on
@@ -322,7 +322,7 @@ checks:
 
 	if (si->lowest_alloc) {
 		/*
-		 * Only set when SWP_DISCARDABLE, and there's a scan
+		 * Only set when SWP_PAGE_DISCARD, and there's a scan
 		 * for a free cluster in progress or just completed.
 		 */
 		if (found_free_cluster) {
@@ -2016,6 +2016,20 @@ static int setup_swap_map_and_extents(struct swap_info_struct *p,
 	return nr_extents;
 }
 
+/*
+ * Helper to sys_swapon determining if a given swap
+ * backing device queue supports DISCARD operations.
+ */
+static bool swap_discardable(struct swap_info_struct *si)
+{
+	struct request_queue *q = bdev_get_queue(si->bdev);
+
+	if (!q || !blk_queue_discard(q))
+		return false;
+
+	return true;
+}
+
 SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 {
 	struct swap_info_struct *p;
@@ -2123,8 +2137,37 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 			p->flags |= SWP_SOLIDSTATE;
 			p->cluster_next = 1 + (prandom_u32() % p->highest_bit);
 		}
-		if ((swap_flags & SWAP_FLAG_DISCARD) && discard_swap(p) == 0)
-			p->flags |= SWP_DISCARDABLE;
+
+		if ((swap_flags & SWAP_FLAG_DISCARD) && swap_discardable(p)) {
+			/*
+			 * When discard is enabled for swap with no particular
+			 * policy flagged, we set all swap discard flags here in
+			 * order to sustain backward compatibility with older
+			 * swapon(8) releases.
+			 */
+			p->flags |= (SWP_DISCARDABLE | SWP_AREA_DISCARD |
+				     SWP_PAGE_DISCARD);
+
+			/*
+			 * By flagging sys_swapon, a sysadmin can tell us to
+			 * either do single-time area discards only, or to just
+			 * perform discards for released swap page-clusters.
+			 * Now it's time to adjust the p->flags accordingly.
+			 */
+			if (swap_flags & SWAP_FLAG_DISCARD_ONCE)
+				p->flags &= ~SWP_PAGE_DISCARD;
+			else if (swap_flags & SWAP_FLAG_DISCARD_PAGES)
+				p->flags &= ~SWP_AREA_DISCARD;
+
+			/* issue a swapon-time discard if it's still required */
+			if (p->flags & SWP_AREA_DISCARD) {
+				int err = discard_swap(p);
+				if (unlikely(err))
+					printk(KERN_ERR
+					       "swapon: discard_swap(%p): %d\n",
+						p, err);
+			}
+		}
 	}
 
 	mutex_lock(&swapon_mutex);
@@ -2135,11 +2178,13 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	enable_swap_info(p, prio, swap_map, frontswap_map);
 
 	printk(KERN_INFO "Adding %uk swap on %s.  "
-			"Priority:%d extents:%d across:%lluk %s%s%s\n",
+			"Priority:%d extents:%d across:%lluk %s%s%s%s%s\n",
 		p->pages<<(PAGE_SHIFT-10), name->name, p->prio,
 		nr_extents, (unsigned long long)span<<(PAGE_SHIFT-10),
 		(p->flags & SWP_SOLIDSTATE) ? "SS" : "",
 		(p->flags & SWP_DISCARDABLE) ? "D" : "",
+		(p->flags & SWP_AREA_DISCARD) ? "s" : "",
+		(p->flags & SWP_PAGE_DISCARD) ? "c" : "",
 		(frontswap_map) ? "FS" : "");
 
 	mutex_unlock(&swapon_mutex);
diff --git a/mm/util.c b/mm/util.c
index ab1424dbe2e..7441c41d00f 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -295,7 +295,6 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
 {
 	mm->mmap_base = TASK_UNMAPPED_BASE;
 	mm->get_unmapped_area = arch_get_unmapped_area;
-	mm->unmap_area = arch_unmap_area;
 }
 #endif
 
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d365724feb0..13a54953a27 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -292,7 +292,7 @@ static struct vmap_area *__find_vmap_area(unsigned long addr)
 		va = rb_entry(n, struct vmap_area, rb_node);
 		if (addr < va->va_start)
 			n = n->rb_left;
-		else if (addr > va->va_start)
+		else if (addr >= va->va_end)
 			n = n->rb_right;
 		else
 			return va;
@@ -388,12 +388,12 @@ nocache:
 		addr = ALIGN(first->va_end, align);
 		if (addr < vstart)
 			goto nocache;
-		if (addr + size - 1 < addr)
+		if (addr + size < addr)
 			goto overflow;
 
 	} else {
 		addr = ALIGN(vstart, align);
-		if (addr + size - 1 < addr)
+		if (addr + size < addr)
 			goto overflow;
 
 		n = vmap_area_root.rb_node;
@@ -420,7 +420,7 @@ nocache:
 		if (addr + cached_hole_size < first->va_start)
 			cached_hole_size = first->va_start - addr;
 		addr = ALIGN(first->va_end, align);
-		if (addr + size - 1 < addr)
+		if (addr + size < addr)
 			goto overflow;
 
 		if (list_is_last(&first->list, &vmap_area_list))
@@ -754,7 +754,6 @@ struct vmap_block {
 	struct vmap_area *va;
 	struct vmap_block_queue *vbq;
 	unsigned long free, dirty;
-	DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
 	DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
 	struct list_head free_list;
 	struct rcu_head rcu_head;
@@ -820,7 +819,6 @@ static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
 	vb->va = va;
 	vb->free = VMAP_BBMAP_BITS;
 	vb->dirty = 0;
-	bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
 	bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
 	INIT_LIST_HEAD(&vb->free_list);
 
@@ -873,7 +871,6 @@ static void purge_fragmented_blocks(int cpu)
 		if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
 			vb->free = 0; /* prevent further allocs after releasing lock */
 			vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
-			bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
 			bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
 			spin_lock(&vbq->lock);
 			list_del_rcu(&vb->free_list);
@@ -891,11 +888,6 @@ static void purge_fragmented_blocks(int cpu)
 	}
 }
 
-static void purge_fragmented_blocks_thiscpu(void)
-{
-	purge_fragmented_blocks(smp_processor_id());
-}
-
 static void purge_fragmented_blocks_allcpus(void)
 {
 	int cpu;
@@ -910,7 +902,6 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
 	struct vmap_block *vb;
 	unsigned long addr = 0;
 	unsigned int order;
-	int purge = 0;
 
 	BUG_ON(size & ~PAGE_MASK);
 	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
@@ -934,17 +925,7 @@ again:
 		if (vb->free < 1UL << order)
 			goto next;
 
-		i = bitmap_find_free_region(vb->alloc_map,
-						VMAP_BBMAP_BITS, order);
-
-		if (i < 0) {
-			if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
-				/* fragmented and no outstanding allocations */
-				BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
-				purge = 1;
-			}
-			goto next;
-		}
+		i = VMAP_BBMAP_BITS - vb->free;
 		addr = vb->va->va_start + (i << PAGE_SHIFT);
 		BUG_ON(addr_to_vb_idx(addr) !=
 				addr_to_vb_idx(vb->va->va_start));
@@ -960,9 +941,6 @@ next:
 		spin_unlock(&vb->lock);
 	}
 
-	if (purge)
-		purge_fragmented_blocks_thiscpu();
-
 	put_cpu_var(vmap_block_queue);
 	rcu_read_unlock();
 
@@ -1311,22 +1289,15 @@ static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
 	spin_unlock(&vmap_area_lock);
 }
 
-static void clear_vm_unlist(struct vm_struct *vm)
+static void clear_vm_uninitialized_flag(struct vm_struct *vm)
 {
 	/*
-	 * Before removing VM_UNLIST,
+	 * Before removing VM_UNINITIALIZED,
 	 * we should make sure that vm has proper values.
 	 * Pair with smp_rmb() in show_numa_info().
 	 */
 	smp_wmb();
-	vm->flags &= ~VM_UNLIST;
-}
-
-static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
-			      unsigned long flags, const void *caller)
-{
-	setup_vmalloc_vm(vm, va, flags, caller);
-	clear_vm_unlist(vm);
+	vm->flags &= ~VM_UNINITIALIZED;
 }
 
 static struct vm_struct *__get_vm_area_node(unsigned long size,
@@ -1337,16 +1308,8 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
 	struct vm_struct *area;
 
 	BUG_ON(in_interrupt());
-	if (flags & VM_IOREMAP) {
-		int bit = fls(size);
-
-		if (bit > IOREMAP_MAX_ORDER)
-			bit = IOREMAP_MAX_ORDER;
-		else if (bit < PAGE_SHIFT)
-			bit = PAGE_SHIFT;
-
-		align = 1ul << bit;
-	}
+	if (flags & VM_IOREMAP)
+		align = 1ul << clamp(fls(size), PAGE_SHIFT, IOREMAP_MAX_ORDER);
 
 	size = PAGE_ALIGN(size);
 	if (unlikely(!size))
@@ -1367,16 +1330,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
 		return NULL;
 	}
 
-	/*
-	 * When this function is called from __vmalloc_node_range,
-	 * we add VM_UNLIST flag to avoid accessing uninitialized
-	 * members of vm_struct such as pages and nr_pages fields.
-	 * They will be set later.
-	 */
-	if (flags & VM_UNLIST)
-		setup_vmalloc_vm(area, va, flags, caller);
-	else
-		insert_vmalloc_vm(area, va, flags, caller);
+	setup_vmalloc_vm(area, va, flags, caller);
 
 	return area;
 }
@@ -1476,10 +1430,9 @@ static void __vunmap(const void *addr, int deallocate_pages)
 	if (!addr)
 		return;
 
-	if ((PAGE_SIZE-1) & (unsigned long)addr) {
-		WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
+	if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
+			addr))
 		return;
-	}
 
 	area = remove_vm_area(addr);
 	if (unlikely(!area)) {
@@ -1524,7 +1477,6 @@ static void __vunmap(const void *addr, int deallocate_pages)
  *	conventions for vfree() arch-depenedent would be a really bad idea)
  *
  *	NOTE: assumes that the object at *addr has a size >= sizeof(llist_node)
- *	
  */
 void vfree(const void *addr)
 {
@@ -1536,8 +1488,8 @@ void vfree(const void *addr)
 		return;
 	if (unlikely(in_interrupt())) {
 		struct vfree_deferred *p = &__get_cpu_var(vfree_deferred);
-		llist_add((struct llist_node *)addr, &p->list);
-		schedule_work(&p->wq);
+		if (llist_add((struct llist_node *)addr, &p->list))
+			schedule_work(&p->wq);
 	} else
 		__vunmap(addr, 1);
 }
@@ -1682,21 +1634,21 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
 	if (!size || (size >> PAGE_SHIFT) > totalram_pages)
 		goto fail;
 
-	area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST,
+	area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED,
 				  start, end, node, gfp_mask, caller);
 	if (!area)
 		goto fail;
 
 	addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
 	if (!addr)
-		return NULL;
+		goto fail;
 
 	/*
-	 * In this function, newly allocated vm_struct has VM_UNLIST flag.
-	 * It means that vm_struct is not fully initialized.
+	 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
+	 * flag. It means that vm_struct is not fully initialized.
 	 * Now, it is fully initialized, so remove this flag here.
 	 */
-	clear_vm_unlist(area);
+	clear_vm_uninitialized_flag(area);
 
 	/*
 	 * A ref_count = 3 is needed because the vm_struct and vmap_area
@@ -2148,42 +2100,43 @@ finished:
 }
 
 /**
- *	remap_vmalloc_range  -  map vmalloc pages to userspace
- *	@vma:		vma to cover (map full range of vma)
- *	@addr:		vmalloc memory
- *	@pgoff:		number of pages into addr before first page to map
+ *	remap_vmalloc_range_partial  -  map vmalloc pages to userspace
+ *	@vma:		vma to cover
+ *	@uaddr:		target user address to start at
+ *	@kaddr:		virtual address of vmalloc kernel memory
+ *	@size:		size of map area
  *
  *	Returns:	0 for success, -Exxx on failure
  *
- *	This function checks that addr is a valid vmalloc'ed area, and
- *	that it is big enough to cover the vma. Will return failure if
- *	that criteria isn't met.
+ *	This function checks that @kaddr is a valid vmalloc'ed area,
+ *	and that it is big enough to cover the range starting at
+ *	@uaddr in @vma. Will return failure if that criteria isn't
+ *	met.
  *
  *	Similar to remap_pfn_range() (see mm/memory.c)
  */
-int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
-						unsigned long pgoff)
+int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
+				void *kaddr, unsigned long size)
 {
 	struct vm_struct *area;
-	unsigned long uaddr = vma->vm_start;
-	unsigned long usize = vma->vm_end - vma->vm_start;
 
-	if ((PAGE_SIZE-1) & (unsigned long)addr)
+	size = PAGE_ALIGN(size);
+
+	if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
 		return -EINVAL;
 
-	area = find_vm_area(addr);
+	area = find_vm_area(kaddr);
 	if (!area)
 		return -EINVAL;
 
 	if (!(area->flags & VM_USERMAP))
 		return -EINVAL;
 
-	if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
+	if (kaddr + size > area->addr + area->size)
 		return -EINVAL;
 
-	addr += pgoff << PAGE_SHIFT;
 	do {
-		struct page *page = vmalloc_to_page(addr);
+		struct page *page = vmalloc_to_page(kaddr);
 		int ret;
 
 		ret = vm_insert_page(vma, uaddr, page);
@@ -2191,14 +2144,37 @@ int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
 			return ret;
 
 		uaddr += PAGE_SIZE;
-		addr += PAGE_SIZE;
-		usize -= PAGE_SIZE;
-	} while (usize > 0);
+		kaddr += PAGE_SIZE;
+		size -= PAGE_SIZE;
+	} while (size > 0);
 
 	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 
 	return 0;
 }
+EXPORT_SYMBOL(remap_vmalloc_range_partial);
+
+/**
+ *	remap_vmalloc_range  -  map vmalloc pages to userspace
+ *	@vma:		vma to cover (map full range of vma)
+ *	@addr:		vmalloc memory
+ *	@pgoff:		number of pages into addr before first page to map
+ *
+ *	Returns:	0 for success, -Exxx on failure
+ *
+ *	This function checks that addr is a valid vmalloc'ed area, and
+ *	that it is big enough to cover the vma. Will return failure if
+ *	that criteria isn't met.
+ *
+ *	Similar to remap_pfn_range() (see mm/memory.c)
+ */
+int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
+						unsigned long pgoff)
+{
+	return remap_vmalloc_range_partial(vma, vma->vm_start,
+					   addr + (pgoff << PAGE_SHIFT),
+					   vma->vm_end - vma->vm_start);
+}
 EXPORT_SYMBOL(remap_vmalloc_range);
 
 /*
@@ -2512,8 +2488,8 @@ found:
 
 	/* insert all vm's */
 	for (area = 0; area < nr_vms; area++)
-		insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
-				  pcpu_get_vm_areas);
+		setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+				 pcpu_get_vm_areas);
 
 	kfree(vas);
 	return vms;
@@ -2592,11 +2568,6 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
 		if (!counters)
 			return;
 
-		/* Pair with smp_wmb() in clear_vm_unlist() */
-		smp_rmb();
-		if (v->flags & VM_UNLIST)
-			return;
-
 		memset(counters, 0, nr_node_ids * sizeof(unsigned int));
 
 		for (nr = 0; nr < v->nr_pages; nr++)
@@ -2625,6 +2596,11 @@ static int s_show(struct seq_file *m, void *p)
 
 	v = va->vm;
 
+	/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+	smp_rmb();
+	if (v->flags & VM_UNINITIALIZED)
+		return 0;
+
 	seq_printf(m, "0x%pK-0x%pK %7ld",
 		v->addr, v->addr + v->size, v->size);
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fa6a85378ee..2cff0d491c6 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -546,7 +546,6 @@ int remove_mapping(struct address_space *mapping, struct page *page)
 void putback_lru_page(struct page *page)
 {
 	int lru;
-	int active = !!TestClearPageActive(page);
 	int was_unevictable = PageUnevictable(page);
 
 	VM_BUG_ON(PageLRU(page));
@@ -561,8 +560,8 @@ redo:
 		 * unevictable page on [in]active list.
 		 * We know how to handle that.
 		 */
-		lru = active + page_lru_base_type(page);
-		lru_cache_add_lru(page, lru);
+		lru = page_lru_base_type(page);
+		lru_cache_add(page);
 	} else {
 		/*
 		 * Put unevictable pages directly on zone's unevictable
@@ -669,6 +668,35 @@ static enum page_references page_check_references(struct page *page,
 	return PAGEREF_RECLAIM;
 }
 
+/* Check if a page is dirty or under writeback */
+static void page_check_dirty_writeback(struct page *page,
+				       bool *dirty, bool *writeback)
+{
+	struct address_space *mapping;
+
+	/*
+	 * Anonymous pages are not handled by flushers and must be written
+	 * from reclaim context. Do not stall reclaim based on them
+	 */
+	if (!page_is_file_cache(page)) {
+		*dirty = false;
+		*writeback = false;
+		return;
+	}
+
+	/* By default assume that the page flags are accurate */
+	*dirty = PageDirty(page);
+	*writeback = PageWriteback(page);
+
+	/* Verify dirty/writeback state if the filesystem supports it */
+	if (!page_has_private(page))
+		return;
+
+	mapping = page_mapping(page);
+	if (mapping && mapping->a_ops->is_dirty_writeback)
+		mapping->a_ops->is_dirty_writeback(page, dirty, writeback);
+}
+
 /*
  * shrink_page_list() returns the number of reclaimed pages
  */
@@ -677,16 +705,21 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 				      struct scan_control *sc,
 				      enum ttu_flags ttu_flags,
 				      unsigned long *ret_nr_dirty,
+				      unsigned long *ret_nr_unqueued_dirty,
+				      unsigned long *ret_nr_congested,
 				      unsigned long *ret_nr_writeback,
+				      unsigned long *ret_nr_immediate,
 				      bool force_reclaim)
 {
 	LIST_HEAD(ret_pages);
 	LIST_HEAD(free_pages);
 	int pgactivate = 0;
+	unsigned long nr_unqueued_dirty = 0;
 	unsigned long nr_dirty = 0;
 	unsigned long nr_congested = 0;
 	unsigned long nr_reclaimed = 0;
 	unsigned long nr_writeback = 0;
+	unsigned long nr_immediate = 0;
 
 	cond_resched();
 
@@ -696,6 +729,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 		struct page *page;
 		int may_enter_fs;
 		enum page_references references = PAGEREF_RECLAIM_CLEAN;
+		bool dirty, writeback;
 
 		cond_resched();
 
@@ -723,25 +757,77 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 		may_enter_fs = (sc->gfp_mask & __GFP_FS) ||
 			(PageSwapCache(page) && (sc->gfp_mask & __GFP_IO));
 
+		/*
+		 * The number of dirty pages determines if a zone is marked
+		 * reclaim_congested which affects wait_iff_congested. kswapd
+		 * will stall and start writing pages if the tail of the LRU
+		 * is all dirty unqueued pages.
+		 */
+		page_check_dirty_writeback(page, &dirty, &writeback);
+		if (dirty || writeback)
+			nr_dirty++;
+
+		if (dirty && !writeback)
+			nr_unqueued_dirty++;
+
+		/*
+		 * Treat this page as congested if the underlying BDI is or if
+		 * pages are cycling through the LRU so quickly that the
+		 * pages marked for immediate reclaim are making it to the
+		 * end of the LRU a second time.
+		 */
+		mapping = page_mapping(page);
+		if ((mapping && bdi_write_congested(mapping->backing_dev_info)) ||
+		    (writeback && PageReclaim(page)))
+			nr_congested++;
+
+		/*
+		 * If a page at the tail of the LRU is under writeback, there
+		 * are three cases to consider.
+		 *
+		 * 1) If reclaim is encountering an excessive number of pages
+		 *    under writeback and this page is both under writeback and
+		 *    PageReclaim then it indicates that pages are being queued
+		 *    for IO but are being recycled through the LRU before the
+		 *    IO can complete. Waiting on the page itself risks an
+		 *    indefinite stall if it is impossible to writeback the
+		 *    page due to IO error or disconnected storage so instead
+		 *    note that the LRU is being scanned too quickly and the
+		 *    caller can stall after page list has been processed.
+		 *
+		 * 2) Global reclaim encounters a page, memcg encounters a
+		 *    page that is not marked for immediate reclaim or
+		 *    the caller does not have __GFP_IO. In this case mark
+		 *    the page for immediate reclaim and continue scanning.
+		 *
+		 *    __GFP_IO is checked  because a loop driver thread might
+		 *    enter reclaim, and deadlock if it waits on a page for
+		 *    which it is needed to do the write (loop masks off
+		 *    __GFP_IO|__GFP_FS for this reason); but more thought
+		 *    would probably show more reasons.
+		 *
+		 *    Don't require __GFP_FS, since we're not going into the
+		 *    FS, just waiting on its writeback completion. Worryingly,
+		 *    ext4 gfs2 and xfs allocate pages with
+		 *    grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so testing
+		 *    may_enter_fs here is liable to OOM on them.
+		 *
+		 * 3) memcg encounters a page that is not already marked
+		 *    PageReclaim. memcg does not have any dirty pages
+		 *    throttling so we could easily OOM just because too many
+		 *    pages are in writeback and there is nothing else to
+		 *    reclaim. Wait for the writeback to complete.
+		 */
 		if (PageWriteback(page)) {
-			/*
-			 * memcg doesn't have any dirty pages throttling so we
-			 * could easily OOM just because too many pages are in
-			 * writeback and there is nothing else to reclaim.
-			 *
-			 * Check __GFP_IO, certainly because a loop driver
-			 * thread might enter reclaim, and deadlock if it waits
-			 * on a page for which it is needed to do the write
-			 * (loop masks off __GFP_IO|__GFP_FS for this reason);
-			 * but more thought would probably show more reasons.
-			 *
-			 * Don't require __GFP_FS, since we're not going into
-			 * the FS, just waiting on its writeback completion.
-			 * Worryingly, ext4 gfs2 and xfs allocate pages with
-			 * grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so
-			 * testing may_enter_fs here is liable to OOM on them.
-			 */
-			if (global_reclaim(sc) ||
+			/* Case 1 above */
+			if (current_is_kswapd() &&
+			    PageReclaim(page) &&
+			    zone_is_reclaim_writeback(zone)) {
+				nr_immediate++;
+				goto keep_locked;
+
+			/* Case 2 above */
+			} else if (global_reclaim(sc) ||
 			    !PageReclaim(page) || !(sc->gfp_mask & __GFP_IO)) {
 				/*
 				 * This is slightly racy - end_page_writeback()
@@ -756,9 +842,13 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 				 */
 				SetPageReclaim(page);
 				nr_writeback++;
+
 				goto keep_locked;
+
+			/* Case 3 above */
+			} else {
+				wait_on_page_writeback(page);
 			}
-			wait_on_page_writeback(page);
 		}
 
 		if (!force_reclaim)
@@ -784,9 +874,10 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			if (!add_to_swap(page, page_list))
 				goto activate_locked;
 			may_enter_fs = 1;
-		}
 
-		mapping = page_mapping(page);
+			/* Adding to swap updated mapping */
+			mapping = page_mapping(page);
+		}
 
 		/*
 		 * The page is mapped into the page tables of one or more
@@ -806,16 +897,14 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 		}
 
 		if (PageDirty(page)) {
-			nr_dirty++;
-
 			/*
 			 * Only kswapd can writeback filesystem pages to
-			 * avoid risk of stack overflow but do not writeback
-			 * unless under significant pressure.
+			 * avoid risk of stack overflow but only writeback
+			 * if many dirty pages have been encountered.
 			 */
 			if (page_is_file_cache(page) &&
 					(!current_is_kswapd() ||
-					 sc->priority >= DEF_PRIORITY - 2)) {
+					 !zone_is_reclaim_dirty(zone))) {
 				/*
 				 * Immediately reclaim when written back.
 				 * Similar in principal to deactivate_page()
@@ -838,7 +927,6 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			/* Page is dirty, try to write it out here */
 			switch (pageout(page, mapping, sc)) {
 			case PAGE_KEEP:
-				nr_congested++;
 				goto keep_locked;
 			case PAGE_ACTIVATE:
 				goto activate_locked;
@@ -946,22 +1034,16 @@ keep:
 		VM_BUG_ON(PageLRU(page) || PageUnevictable(page));
 	}
 
-	/*
-	 * Tag a zone as congested if all the dirty pages encountered were
-	 * backed by a congested BDI. In this case, reclaimers should just
-	 * back off and wait for congestion to clear because further reclaim
-	 * will encounter the same problem
-	 */
-	if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
-		zone_set_flag(zone, ZONE_CONGESTED);
-
 	free_hot_cold_page_list(&free_pages, 1);
 
 	list_splice(&ret_pages, page_list);
 	count_vm_events(PGACTIVATE, pgactivate);
 	mem_cgroup_uncharge_end();
 	*ret_nr_dirty += nr_dirty;
+	*ret_nr_congested += nr_congested;
+	*ret_nr_unqueued_dirty += nr_unqueued_dirty;
 	*ret_nr_writeback += nr_writeback;
+	*ret_nr_immediate += nr_immediate;
 	return nr_reclaimed;
 }
 
@@ -973,7 +1055,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
 		.priority = DEF_PRIORITY,
 		.may_unmap = 1,
 	};
-	unsigned long ret, dummy1, dummy2;
+	unsigned long ret, dummy1, dummy2, dummy3, dummy4, dummy5;
 	struct page *page, *next;
 	LIST_HEAD(clean_pages);
 
@@ -985,8 +1067,8 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
 	}
 
 	ret = shrink_page_list(&clean_pages, zone, &sc,
-				TTU_UNMAP|TTU_IGNORE_ACCESS,
-				&dummy1, &dummy2, true);
+			TTU_UNMAP|TTU_IGNORE_ACCESS,
+			&dummy1, &dummy2, &dummy3, &dummy4, &dummy5, true);
 	list_splice(&clean_pages, page_list);
 	__mod_zone_page_state(zone, NR_ISOLATED_FILE, -ret);
 	return ret;
@@ -1281,7 +1363,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
 	unsigned long nr_reclaimed = 0;
 	unsigned long nr_taken;
 	unsigned long nr_dirty = 0;
+	unsigned long nr_congested = 0;
+	unsigned long nr_unqueued_dirty = 0;
 	unsigned long nr_writeback = 0;
+	unsigned long nr_immediate = 0;
 	isolate_mode_t isolate_mode = 0;
 	int file = is_file_lru(lru);
 	struct zone *zone = lruvec_zone(lruvec);
@@ -1323,7 +1408,9 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
 		return 0;
 
 	nr_reclaimed = shrink_page_list(&page_list, zone, sc, TTU_UNMAP,
-					&nr_dirty, &nr_writeback, false);
+				&nr_dirty, &nr_unqueued_dirty, &nr_congested,
+				&nr_writeback, &nr_immediate,
+				false);
 
 	spin_lock_irq(&zone->lru_lock);
 
@@ -1356,21 +1443,51 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
 	 * as there is no guarantee the dirtying process is throttled in the
 	 * same way balance_dirty_pages() manages.
 	 *
-	 * This scales the number of dirty pages that must be under writeback
-	 * before throttling depending on priority. It is a simple backoff
-	 * function that has the most effect in the range DEF_PRIORITY to
-	 * DEF_PRIORITY-2 which is the priority reclaim is considered to be
-	 * in trouble and reclaim is considered to be in trouble.
-	 *
-	 * DEF_PRIORITY   100% isolated pages must be PageWriteback to throttle
-	 * DEF_PRIORITY-1  50% must be PageWriteback
-	 * DEF_PRIORITY-2  25% must be PageWriteback, kswapd in trouble
-	 * ...
-	 * DEF_PRIORITY-6 For SWAP_CLUSTER_MAX isolated pages, throttle if any
-	 *                     isolated page is PageWriteback
+	 * Once a zone is flagged ZONE_WRITEBACK, kswapd will count the number
+	 * of pages under pages flagged for immediate reclaim and stall if any
+	 * are encountered in the nr_immediate check below.
+	 */
+	if (nr_writeback && nr_writeback == nr_taken)
+		zone_set_flag(zone, ZONE_WRITEBACK);
+
+	/*
+	 * memcg will stall in page writeback so only consider forcibly
+	 * stalling for global reclaim
 	 */
-	if (nr_writeback && nr_writeback >=
-			(nr_taken >> (DEF_PRIORITY - sc->priority)))
+	if (global_reclaim(sc)) {
+		/*
+		 * Tag a zone as congested if all the dirty pages scanned were
+		 * backed by a congested BDI and wait_iff_congested will stall.
+		 */
+		if (nr_dirty && nr_dirty == nr_congested)
+			zone_set_flag(zone, ZONE_CONGESTED);
+
+		/*
+		 * If dirty pages are scanned that are not queued for IO, it
+		 * implies that flushers are not keeping up. In this case, flag
+		 * the zone ZONE_TAIL_LRU_DIRTY and kswapd will start writing
+		 * pages from reclaim context. It will forcibly stall in the
+		 * next check.
+		 */
+		if (nr_unqueued_dirty == nr_taken)
+			zone_set_flag(zone, ZONE_TAIL_LRU_DIRTY);
+
+		/*
+		 * In addition, if kswapd scans pages marked marked for
+		 * immediate reclaim and under writeback (nr_immediate), it
+		 * implies that pages are cycling through the LRU faster than
+		 * they are written so also forcibly stall.
+		 */
+		if (nr_unqueued_dirty == nr_taken || nr_immediate)
+			congestion_wait(BLK_RW_ASYNC, HZ/10);
+	}
+
+	/*
+	 * Stall direct reclaim for IO completions if underlying BDIs or zone
+	 * is congested. Allow kswapd to continue until it starts encountering
+	 * unqueued dirty pages or cycling through the LRU too quickly.
+	 */
+	if (!sc->hibernation_mode && !current_is_kswapd())
 		wait_iff_congested(zone, BLK_RW_ASYNC, HZ/10);
 
 	trace_mm_vmscan_lru_shrink_inactive(zone->zone_pgdat->node_id,
@@ -1822,17 +1939,25 @@ out:
 static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
 {
 	unsigned long nr[NR_LRU_LISTS];
+	unsigned long targets[NR_LRU_LISTS];
 	unsigned long nr_to_scan;
 	enum lru_list lru;
 	unsigned long nr_reclaimed = 0;
 	unsigned long nr_to_reclaim = sc->nr_to_reclaim;
 	struct blk_plug plug;
+	bool scan_adjusted = false;
 
 	get_scan_count(lruvec, sc, nr);
 
+	/* Record the original scan target for proportional adjustments later */
+	memcpy(targets, nr, sizeof(nr));
+
 	blk_start_plug(&plug);
 	while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
 					nr[LRU_INACTIVE_FILE]) {
+		unsigned long nr_anon, nr_file, percentage;
+		unsigned long nr_scanned;
+
 		for_each_evictable_lru(lru) {
 			if (nr[lru]) {
 				nr_to_scan = min(nr[lru], SWAP_CLUSTER_MAX);
@@ -1842,17 +1967,60 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
 							    lruvec, sc);
 			}
 		}
+
+		if (nr_reclaimed < nr_to_reclaim || scan_adjusted)
+			continue;
+
 		/*
-		 * On large memory systems, scan >> priority can become
-		 * really large. This is fine for the starting priority;
-		 * we want to put equal scanning pressure on each zone.
-		 * However, if the VM has a harder time of freeing pages,
-		 * with multiple processes reclaiming pages, the total
-		 * freeing target can get unreasonably large.
+		 * For global direct reclaim, reclaim only the number of pages
+		 * requested. Less care is taken to scan proportionally as it
+		 * is more important to minimise direct reclaim stall latency
+		 * than it is to properly age the LRU lists.
 		 */
-		if (nr_reclaimed >= nr_to_reclaim &&
-		    sc->priority < DEF_PRIORITY)
+		if (global_reclaim(sc) && !current_is_kswapd())
 			break;
+
+		/*
+		 * For kswapd and memcg, reclaim at least the number of pages
+		 * requested. Ensure that the anon and file LRUs shrink
+		 * proportionally what was requested by get_scan_count(). We
+		 * stop reclaiming one LRU and reduce the amount scanning
+		 * proportional to the original scan target.
+		 */
+		nr_file = nr[LRU_INACTIVE_FILE] + nr[LRU_ACTIVE_FILE];
+		nr_anon = nr[LRU_INACTIVE_ANON] + nr[LRU_ACTIVE_ANON];
+
+		if (nr_file > nr_anon) {
+			unsigned long scan_target = targets[LRU_INACTIVE_ANON] +
+						targets[LRU_ACTIVE_ANON] + 1;
+			lru = LRU_BASE;
+			percentage = nr_anon * 100 / scan_target;
+		} else {
+			unsigned long scan_target = targets[LRU_INACTIVE_FILE] +
+						targets[LRU_ACTIVE_FILE] + 1;
+			lru = LRU_FILE;
+			percentage = nr_file * 100 / scan_target;
+		}
+
+		/* Stop scanning the smaller of the LRU */
+		nr[lru] = 0;
+		nr[lru + LRU_ACTIVE] = 0;
+
+		/*
+		 * Recalculate the other LRU scan count based on its original
+		 * scan target and the percentage scanning already complete
+		 */
+		lru = (lru == LRU_FILE) ? LRU_BASE : LRU_FILE;
+		nr_scanned = targets[lru] - nr[lru];
+		nr[lru] = targets[lru] * (100 - percentage) / 100;
+		nr[lru] -= min(nr[lru], nr_scanned);
+
+		lru += LRU_ACTIVE;
+		nr_scanned = targets[lru] - nr[lru];
+		nr[lru] = targets[lru] * (100 - percentage) / 100;
+		nr[lru] -= min(nr[lru], nr_scanned);
+
+		scan_adjusted = true;
 	}
 	blk_finish_plug(&plug);
 	sc->nr_reclaimed += nr_reclaimed;
@@ -2179,8 +2347,10 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 		aborted_reclaim = shrink_zones(zonelist, sc);
 
 		/*
-		 * Don't shrink slabs when reclaiming memory from
-		 * over limit cgroups
+		 * Don't shrink slabs when reclaiming memory from over limit
+		 * cgroups but do shrink slab at least once when aborting
+		 * reclaim for compaction to avoid unevenly scanning file/anon
+		 * LRU pages over slab pages.
 		 */
 		if (global_reclaim(sc)) {
 			unsigned long lru_pages = 0;
@@ -2222,18 +2392,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 						WB_REASON_TRY_TO_FREE_PAGES);
 			sc->may_writepage = 1;
 		}
-
-		/* Take a nap, wait for some writeback to complete */
-		if (!sc->hibernation_mode && sc->nr_scanned &&
-		    sc->priority < DEF_PRIORITY - 2) {
-			struct zone *preferred_zone;
-
-			first_zones_zonelist(zonelist, gfp_zone(sc->gfp_mask),
-						&cpuset_current_mems_allowed,
-						&preferred_zone);
-			wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/10);
-		}
-	} while (--sc->priority >= 0);
+	} while (--sc->priority >= 0 && !aborted_reclaim);
 
 out:
 	delayacct_freepages_end();
@@ -2601,6 +2760,91 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
 }
 
 /*
+ * kswapd shrinks the zone by the number of pages required to reach
+ * the high watermark.
+ *
+ * Returns true if kswapd scanned at least the requested number of pages to
+ * reclaim or if the lack of progress was due to pages under writeback.
+ * This is used to determine if the scanning priority needs to be raised.
+ */
+static bool kswapd_shrink_zone(struct zone *zone,
+			       int classzone_idx,
+			       struct scan_control *sc,
+			       unsigned long lru_pages,
+			       unsigned long *nr_attempted)
+{
+	unsigned long nr_slab;
+	int testorder = sc->order;
+	unsigned long balance_gap;
+	struct reclaim_state *reclaim_state = current->reclaim_state;
+	struct shrink_control shrink = {
+		.gfp_mask = sc->gfp_mask,
+	};
+	bool lowmem_pressure;
+
+	/* Reclaim above the high watermark. */
+	sc->nr_to_reclaim = max(SWAP_CLUSTER_MAX, high_wmark_pages(zone));
+
+	/*
+	 * Kswapd reclaims only single pages with compaction enabled. Trying
+	 * too hard to reclaim until contiguous free pages have become
+	 * available can hurt performance by evicting too much useful data
+	 * from memory. Do not reclaim more than needed for compaction.
+	 */
+	if (IS_ENABLED(CONFIG_COMPACTION) && sc->order &&
+			compaction_suitable(zone, sc->order) !=
+				COMPACT_SKIPPED)
+		testorder = 0;
+
+	/*
+	 * We put equal pressure on every zone, unless one zone has way too
+	 * many pages free already. The "too many pages" is defined as the
+	 * high wmark plus a "gap" where the gap is either the low
+	 * watermark or 1% of the zone, whichever is smaller.
+	 */
+	balance_gap = min(low_wmark_pages(zone),
+		(zone->managed_pages + KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
+		KSWAPD_ZONE_BALANCE_GAP_RATIO);
+
+	/*
+	 * If there is no low memory pressure or the zone is balanced then no
+	 * reclaim is necessary
+	 */
+	lowmem_pressure = (buffer_heads_over_limit && is_highmem(zone));
+	if (!lowmem_pressure && zone_balanced(zone, testorder,
+						balance_gap, classzone_idx))
+		return true;
+
+	shrink_zone(zone, sc);
+
+	reclaim_state->reclaimed_slab = 0;
+	nr_slab = shrink_slab(&shrink, sc->nr_scanned, lru_pages);
+	sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+
+	/* Account for the number of pages attempted to reclaim */
+	*nr_attempted += sc->nr_to_reclaim;
+
+	if (nr_slab == 0 && !zone_reclaimable(zone))
+		zone->all_unreclaimable = 1;
+
+	zone_clear_flag(zone, ZONE_WRITEBACK);
+
+	/*
+	 * If a zone reaches its high watermark, consider it to be no longer
+	 * congested. It's possible there are dirty pages backed by congested
+	 * BDIs but as pressure is relieved, speculatively avoid congestion
+	 * waits.
+	 */
+	if (!zone->all_unreclaimable &&
+	    zone_balanced(zone, testorder, 0, classzone_idx)) {
+		zone_clear_flag(zone, ZONE_CONGESTED);
+		zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);
+	}
+
+	return sc->nr_scanned >= sc->nr_to_reclaim;
+}
+
+/*
  * For kswapd, balance_pgdat() will work across all this node's zones until
  * they are all at high_wmark_pages(zone).
  *
@@ -2624,35 +2868,28 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
 static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 							int *classzone_idx)
 {
-	bool pgdat_is_balanced = false;
 	int i;
 	int end_zone = 0;	/* Inclusive.  0 = ZONE_DMA */
-	struct reclaim_state *reclaim_state = current->reclaim_state;
 	unsigned long nr_soft_reclaimed;
 	unsigned long nr_soft_scanned;
 	struct scan_control sc = {
 		.gfp_mask = GFP_KERNEL,
+		.priority = DEF_PRIORITY,
 		.may_unmap = 1,
 		.may_swap = 1,
-		/*
-		 * kswapd doesn't want to be bailed out while reclaim. because
-		 * we want to put equal scanning pressure on each zone.
-		 */
-		.nr_to_reclaim = ULONG_MAX,
+		.may_writepage = !laptop_mode,
 		.order = order,
 		.target_mem_cgroup = NULL,
 	};
-	struct shrink_control shrink = {
-		.gfp_mask = sc.gfp_mask,
-	};
-loop_again:
-	sc.priority = DEF_PRIORITY;
-	sc.nr_reclaimed = 0;
-	sc.may_writepage = !laptop_mode;
 	count_vm_event(PAGEOUTRUN);
 
 	do {
 		unsigned long lru_pages = 0;
+		unsigned long nr_attempted = 0;
+		bool raise_priority = true;
+		bool pgdat_needs_compaction = (order > 0);
+
+		sc.nr_reclaimed = 0;
 
 		/*
 		 * Scan in the highmem->dma direction for the highest
@@ -2689,23 +2926,46 @@ loop_again:
 				end_zone = i;
 				break;
 			} else {
-				/* If balanced, clear the congested flag */
+				/*
+				 * If balanced, clear the dirty and congested
+				 * flags
+				 */
 				zone_clear_flag(zone, ZONE_CONGESTED);
+				zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);
 			}
 		}
 
-		if (i < 0) {
-			pgdat_is_balanced = true;
+		if (i < 0)
 			goto out;
-		}
 
 		for (i = 0; i <= end_zone; i++) {
 			struct zone *zone = pgdat->node_zones + i;
 
+			if (!populated_zone(zone))
+				continue;
+
 			lru_pages += zone_reclaimable_pages(zone);
+
+			/*
+			 * If any zone is currently balanced then kswapd will
+			 * not call compaction as it is expected that the
+			 * necessary pages are already available.
+			 */
+			if (pgdat_needs_compaction &&
+					zone_watermark_ok(zone, order,
+						low_wmark_pages(zone),
+						*classzone_idx, 0))
+				pgdat_needs_compaction = false;
 		}
 
 		/*
+		 * If we're getting trouble reclaiming, start doing writepage
+		 * even in laptop mode.
+		 */
+		if (sc.priority < DEF_PRIORITY - 2)
+			sc.may_writepage = 1;
+
+		/*
 		 * Now scan the zone in the dma->highmem direction, stopping
 		 * at the last zone which needs scanning.
 		 *
@@ -2716,8 +2976,6 @@ loop_again:
 		 */
 		for (i = 0; i <= end_zone; i++) {
 			struct zone *zone = pgdat->node_zones + i;
-			int nr_slab, testorder;
-			unsigned long balance_gap;
 
 			if (!populated_zone(zone))
 				continue;
@@ -2738,65 +2996,14 @@ loop_again:
 			sc.nr_reclaimed += nr_soft_reclaimed;
 
 			/*
-			 * We put equal pressure on every zone, unless
-			 * one zone has way too many pages free
-			 * already. The "too many pages" is defined
-			 * as the high wmark plus a "gap" where the
-			 * gap is either the low watermark or 1%
-			 * of the zone, whichever is smaller.
+			 * There should be no need to raise the scanning
+			 * priority if enough pages are already being scanned
+			 * that that high watermark would be met at 100%
+			 * efficiency.
 			 */
-			balance_gap = min(low_wmark_pages(zone),
-				(zone->managed_pages +
-					KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
-				KSWAPD_ZONE_BALANCE_GAP_RATIO);
-			/*
-			 * Kswapd reclaims only single pages with compaction
-			 * enabled. Trying too hard to reclaim until contiguous
-			 * free pages have become available can hurt performance
-			 * by evicting too much useful data from memory.
-			 * Do not reclaim more than needed for compaction.
-			 */
-			testorder = order;
-			if (IS_ENABLED(CONFIG_COMPACTION) && order &&
-					compaction_suitable(zone, order) !=
-						COMPACT_SKIPPED)
-				testorder = 0;
-
-			if ((buffer_heads_over_limit && is_highmem_idx(i)) ||
-			    !zone_balanced(zone, testorder,
-					   balance_gap, end_zone)) {
-				shrink_zone(zone, &sc);
-
-				reclaim_state->reclaimed_slab = 0;
-				nr_slab = shrink_slab(&shrink, sc.nr_scanned, lru_pages);
-				sc.nr_reclaimed += reclaim_state->reclaimed_slab;
-
-				if (nr_slab == 0 && !zone_reclaimable(zone))
-					zone->all_unreclaimable = 1;
-			}
-
-			/*
-			 * If we're getting trouble reclaiming, start doing
-			 * writepage even in laptop mode.
-			 */
-			if (sc.priority < DEF_PRIORITY - 2)
-				sc.may_writepage = 1;
-
-			if (zone->all_unreclaimable) {
-				if (end_zone && end_zone == i)
-					end_zone--;
-				continue;
-			}
-
-			if (zone_balanced(zone, testorder, 0, end_zone))
-				/*
-				 * If a zone reaches its high watermark,
-				 * consider it to be no longer congested. It's
-				 * possible there are dirty pages backed by
-				 * congested BDIs but as pressure is relieved,
-				 * speculatively avoid congestion waits
-				 */
-				zone_clear_flag(zone, ZONE_CONGESTED);
+			if (kswapd_shrink_zone(zone, end_zone, &sc,
+					lru_pages, &nr_attempted))
+				raise_priority = false;
 		}
 
 		/*
@@ -2808,74 +3015,38 @@ loop_again:
 				pfmemalloc_watermark_ok(pgdat))
 			wake_up(&pgdat->pfmemalloc_wait);
 
-		if (pgdat_balanced(pgdat, order, *classzone_idx)) {
-			pgdat_is_balanced = true;
-			break;		/* kswapd: all done */
-		}
-
 		/*
-		 * We do this so kswapd doesn't build up large priorities for
-		 * example when it is freeing in parallel with allocators. It
-		 * matches the direct reclaim path behaviour in terms of impact
-		 * on zone->*_priority.
+		 * Fragmentation may mean that the system cannot be rebalanced
+		 * for high-order allocations in all zones. If twice the
+		 * allocation size has been reclaimed and the zones are still
+		 * not balanced then recheck the watermarks at order-0 to
+		 * prevent kswapd reclaiming excessively. Assume that a
+		 * process requested a high-order can direct reclaim/compact.
 		 */
-		if (sc.nr_reclaimed >= SWAP_CLUSTER_MAX)
-			break;
-	} while (--sc.priority >= 0);
-
-out:
-	if (!pgdat_is_balanced) {
-		cond_resched();
+		if (order && sc.nr_reclaimed >= 2UL << order)
+			order = sc.order = 0;
 
-		try_to_freeze();
+		/* Check if kswapd should be suspending */
+		if (try_to_freeze() || kthread_should_stop())
+			break;
 
 		/*
-		 * Fragmentation may mean that the system cannot be
-		 * rebalanced for high-order allocations in all zones.
-		 * At this point, if nr_reclaimed < SWAP_CLUSTER_MAX,
-		 * it means the zones have been fully scanned and are still
-		 * not balanced. For high-order allocations, there is
-		 * little point trying all over again as kswapd may
-		 * infinite loop.
-		 *
-		 * Instead, recheck all watermarks at order-0 as they
-		 * are the most important. If watermarks are ok, kswapd will go
-		 * back to sleep. High-order users can still perform direct
-		 * reclaim if they wish.
+		 * Compact if necessary and kswapd is reclaiming at least the
+		 * high watermark number of pages as requsted
 		 */
-		if (sc.nr_reclaimed < SWAP_CLUSTER_MAX)
-			order = sc.order = 0;
-
-		goto loop_again;
-	}
-
-	/*
-	 * If kswapd was reclaiming at a higher order, it has the option of
-	 * sleeping without all zones being balanced. Before it does, it must
-	 * ensure that the watermarks for order-0 on *all* zones are met and
-	 * that the congestion flags are cleared. The congestion flag must
-	 * be cleared as kswapd is the only mechanism that clears the flag
-	 * and it is potentially going to sleep here.
-	 */
-	if (order) {
-		int zones_need_compaction = 1;
-
-		for (i = 0; i <= end_zone; i++) {
-			struct zone *zone = pgdat->node_zones + i;
-
-			if (!populated_zone(zone))
-				continue;
-
-			/* Check if the memory needs to be defragmented. */
-			if (zone_watermark_ok(zone, order,
-				    low_wmark_pages(zone), *classzone_idx, 0))
-				zones_need_compaction = 0;
-		}
-
-		if (zones_need_compaction)
+		if (pgdat_needs_compaction && sc.nr_reclaimed > nr_attempted)
 			compact_pgdat(pgdat, order);
-	}
 
+		/*
+		 * Raise priority if scanning rate is too low or there was no
+		 * progress in reclaiming pages
+		 */
+		if (raise_priority || !sc.nr_reclaimed)
+			sc.priority--;
+	} while (sc.priority >= 1 &&
+		 !pgdat_balanced(pgdat, order, *classzone_idx));
+
+out:
 	/*
 	 * Return the order we were reclaiming at so prepare_kswapd_sleep()
 	 * makes a decision on the order we were last reclaiming at. However,
diff --git a/mm/zbud.c b/mm/zbud.c
new file mode 100644
index 00000000000..9bb4710e358
--- /dev/null
+++ b/mm/zbud.c
@@ -0,0 +1,527 @@
+/*
+ * zbud.c
+ *
+ * Copyright (C) 2013, Seth Jennings, IBM
+ *
+ * Concepts based on zcache internal zbud allocator by Dan Magenheimer.
+ *
+ * zbud is an special purpose allocator for storing compressed pages.  Contrary
+ * to what its name may suggest, zbud is not a buddy allocator, but rather an
+ * allocator that "buddies" two compressed pages together in a single memory
+ * page.
+ *
+ * While this design limits storage density, it has simple and deterministic
+ * reclaim properties that make it preferable to a higher density approach when
+ * reclaim will be used.
+ *
+ * zbud works by storing compressed pages, or "zpages", together in pairs in a
+ * single memory page called a "zbud page".  The first buddy is "left
+ * justifed" at the beginning of the zbud page, and the last buddy is "right
+ * justified" at the end of the zbud page.  The benefit is that if either
+ * buddy is freed, the freed buddy space, coalesced with whatever slack space
+ * that existed between the buddies, results in the largest possible free region
+ * within the zbud page.
+ *
+ * zbud also provides an attractive lower bound on density. The ratio of zpages
+ * to zbud pages can not be less than 1.  This ensures that zbud can never "do
+ * harm" by using more pages to store zpages than the uncompressed zpages would
+ * have used on their own.
+ *
+ * zbud pages are divided into "chunks".  The size of the chunks is fixed at
+ * compile time and determined by NCHUNKS_ORDER below.  Dividing zbud pages
+ * into chunks allows organizing unbuddied zbud pages into a manageable number
+ * of unbuddied lists according to the number of free chunks available in the
+ * zbud page.
+ *
+ * The zbud API differs from that of conventional allocators in that the
+ * allocation function, zbud_alloc(), returns an opaque handle to the user,
+ * not a dereferenceable pointer.  The user must map the handle using
+ * zbud_map() in order to get a usable pointer by which to access the
+ * allocation data and unmap the handle with zbud_unmap() when operations
+ * on the allocation data are complete.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/atomic.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/preempt.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/zbud.h>
+
+/*****************
+ * Structures
+*****************/
+/*
+ * NCHUNKS_ORDER determines the internal allocation granularity, effectively
+ * adjusting internal fragmentation.  It also determines the number of
+ * freelists maintained in each pool. NCHUNKS_ORDER of 6 means that the
+ * allocation granularity will be in chunks of size PAGE_SIZE/64, and there
+ * will be 64 freelists per pool.
+ */
+#define NCHUNKS_ORDER	6
+
+#define CHUNK_SHIFT	(PAGE_SHIFT - NCHUNKS_ORDER)
+#define CHUNK_SIZE	(1 << CHUNK_SHIFT)
+#define NCHUNKS		(PAGE_SIZE >> CHUNK_SHIFT)
+#define ZHDR_SIZE_ALIGNED CHUNK_SIZE
+
+/**
+ * struct zbud_pool - stores metadata for each zbud pool
+ * @lock:	protects all pool fields and first|last_chunk fields of any
+ *		zbud page in the pool
+ * @unbuddied:	array of lists tracking zbud pages that only contain one buddy;
+ *		the lists each zbud page is added to depends on the size of
+ *		its free region.
+ * @buddied:	list tracking the zbud pages that contain two buddies;
+ *		these zbud pages are full
+ * @lru:	list tracking the zbud pages in LRU order by most recently
+ *		added buddy.
+ * @pages_nr:	number of zbud pages in the pool.
+ * @ops:	pointer to a structure of user defined operations specified at
+ *		pool creation time.
+ *
+ * This structure is allocated at pool creation time and maintains metadata
+ * pertaining to a particular zbud pool.
+ */
+struct zbud_pool {
+	spinlock_t lock;
+	struct list_head unbuddied[NCHUNKS];
+	struct list_head buddied;
+	struct list_head lru;
+	u64 pages_nr;
+	struct zbud_ops *ops;
+};
+
+/*
+ * struct zbud_header - zbud page metadata occupying the first chunk of each
+ *			zbud page.
+ * @buddy:	links the zbud page into the unbuddied/buddied lists in the pool
+ * @lru:	links the zbud page into the lru list in the pool
+ * @first_chunks:	the size of the first buddy in chunks, 0 if free
+ * @last_chunks:	the size of the last buddy in chunks, 0 if free
+ */
+struct zbud_header {
+	struct list_head buddy;
+	struct list_head lru;
+	unsigned int first_chunks;
+	unsigned int last_chunks;
+	bool under_reclaim;
+};
+
+/*****************
+ * Helpers
+*****************/
+/* Just to make the code easier to read */
+enum buddy {
+	FIRST,
+	LAST
+};
+
+/* Converts an allocation size in bytes to size in zbud chunks */
+static int size_to_chunks(int size)
+{
+	return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT;
+}
+
+#define for_each_unbuddied_list(_iter, _begin) \
+	for ((_iter) = (_begin); (_iter) < NCHUNKS; (_iter)++)
+
+/* Initializes the zbud header of a newly allocated zbud page */
+static struct zbud_header *init_zbud_page(struct page *page)
+{
+	struct zbud_header *zhdr = page_address(page);
+	zhdr->first_chunks = 0;
+	zhdr->last_chunks = 0;
+	INIT_LIST_HEAD(&zhdr->buddy);
+	INIT_LIST_HEAD(&zhdr->lru);
+	zhdr->under_reclaim = 0;
+	return zhdr;
+}
+
+/* Resets the struct page fields and frees the page */
+static void free_zbud_page(struct zbud_header *zhdr)
+{
+	__free_page(virt_to_page(zhdr));
+}
+
+/*
+ * Encodes the handle of a particular buddy within a zbud page
+ * Pool lock should be held as this function accesses first|last_chunks
+ */
+static unsigned long encode_handle(struct zbud_header *zhdr, enum buddy bud)
+{
+	unsigned long handle;
+
+	/*
+	 * For now, the encoded handle is actually just the pointer to the data
+	 * but this might not always be the case.  A little information hiding.
+	 * Add CHUNK_SIZE to the handle if it is the first allocation to jump
+	 * over the zbud header in the first chunk.
+	 */
+	handle = (unsigned long)zhdr;
+	if (bud == FIRST)
+		/* skip over zbud header */
+		handle += ZHDR_SIZE_ALIGNED;
+	else /* bud == LAST */
+		handle += PAGE_SIZE - (zhdr->last_chunks  << CHUNK_SHIFT);
+	return handle;
+}
+
+/* Returns the zbud page where a given handle is stored */
+static struct zbud_header *handle_to_zbud_header(unsigned long handle)
+{
+	return (struct zbud_header *)(handle & PAGE_MASK);
+}
+
+/* Returns the number of free chunks in a zbud page */
+static int num_free_chunks(struct zbud_header *zhdr)
+{
+	/*
+	 * Rather than branch for different situations, just use the fact that
+	 * free buddies have a length of zero to simplify everything. -1 at the
+	 * end for the zbud header.
+	 */
+	return NCHUNKS - zhdr->first_chunks - zhdr->last_chunks - 1;
+}
+
+/*****************
+ * API Functions
+*****************/
+/**
+ * zbud_create_pool() - create a new zbud pool
+ * @gfp:	gfp flags when allocating the zbud pool structure
+ * @ops:	user-defined operations for the zbud pool
+ *
+ * Return: pointer to the new zbud pool or NULL if the metadata allocation
+ * failed.
+ */
+struct zbud_pool *zbud_create_pool(gfp_t gfp, struct zbud_ops *ops)
+{
+	struct zbud_pool *pool;
+	int i;
+
+	pool = kmalloc(sizeof(struct zbud_pool), gfp);
+	if (!pool)
+		return NULL;
+	spin_lock_init(&pool->lock);
+	for_each_unbuddied_list(i, 0)
+		INIT_LIST_HEAD(&pool->unbuddied[i]);
+	INIT_LIST_HEAD(&pool->buddied);
+	INIT_LIST_HEAD(&pool->lru);
+	pool->pages_nr = 0;
+	pool->ops = ops;
+	return pool;
+}
+
+/**
+ * zbud_destroy_pool() - destroys an existing zbud pool
+ * @pool:	the zbud pool to be destroyed
+ *
+ * The pool should be emptied before this function is called.
+ */
+void zbud_destroy_pool(struct zbud_pool *pool)
+{
+	kfree(pool);
+}
+
+/**
+ * zbud_alloc() - allocates a region of a given size
+ * @pool:	zbud pool from which to allocate
+ * @size:	size in bytes of the desired allocation
+ * @gfp:	gfp flags used if the pool needs to grow
+ * @handle:	handle of the new allocation
+ *
+ * This function will attempt to find a free region in the pool large enough to
+ * satisfy the allocation request.  A search of the unbuddied lists is
+ * performed first. If no suitable free region is found, then a new page is
+ * allocated and added to the pool to satisfy the request.
+ *
+ * gfp should not set __GFP_HIGHMEM as highmem pages cannot be used
+ * as zbud pool pages.
+ *
+ * Return: 0 if success and handle is set, otherwise -EINVAL is the size or
+ * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate
+ * a new page.
+ */
+int zbud_alloc(struct zbud_pool *pool, int size, gfp_t gfp,
+			unsigned long *handle)
+{
+	int chunks, i, freechunks;
+	struct zbud_header *zhdr = NULL;
+	enum buddy bud;
+	struct page *page;
+
+	if (size <= 0 || gfp & __GFP_HIGHMEM)
+		return -EINVAL;
+	if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED)
+		return -ENOSPC;
+	chunks = size_to_chunks(size);
+	spin_lock(&pool->lock);
+
+	/* First, try to find an unbuddied zbud page. */
+	zhdr = NULL;
+	for_each_unbuddied_list(i, chunks) {
+		if (!list_empty(&pool->unbuddied[i])) {
+			zhdr = list_first_entry(&pool->unbuddied[i],
+					struct zbud_header, buddy);
+			list_del(&zhdr->buddy);
+			if (zhdr->first_chunks == 0)
+				bud = FIRST;
+			else
+				bud = LAST;
+			goto found;
+		}
+	}
+
+	/* Couldn't find unbuddied zbud page, create new one */
+	spin_unlock(&pool->lock);
+	page = alloc_page(gfp);
+	if (!page)
+		return -ENOMEM;
+	spin_lock(&pool->lock);
+	pool->pages_nr++;
+	zhdr = init_zbud_page(page);
+	bud = FIRST;
+
+found:
+	if (bud == FIRST)
+		zhdr->first_chunks = chunks;
+	else
+		zhdr->last_chunks = chunks;
+
+	if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0) {
+		/* Add to unbuddied list */
+		freechunks = num_free_chunks(zhdr);
+		list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
+	} else {
+		/* Add to buddied list */
+		list_add(&zhdr->buddy, &pool->buddied);
+	}
+
+	/* Add/move zbud page to beginning of LRU */
+	if (!list_empty(&zhdr->lru))
+		list_del(&zhdr->lru);
+	list_add(&zhdr->lru, &pool->lru);
+
+	*handle = encode_handle(zhdr, bud);
+	spin_unlock(&pool->lock);
+
+	return 0;
+}
+
+/**
+ * zbud_free() - frees the allocation associated with the given handle
+ * @pool:	pool in which the allocation resided
+ * @handle:	handle associated with the allocation returned by zbud_alloc()
+ *
+ * In the case that the zbud page in which the allocation resides is under
+ * reclaim, as indicated by the PG_reclaim flag being set, this function
+ * only sets the first|last_chunks to 0.  The page is actually freed
+ * once both buddies are evicted (see zbud_reclaim_page() below).
+ */
+void zbud_free(struct zbud_pool *pool, unsigned long handle)
+{
+	struct zbud_header *zhdr;
+	int freechunks;
+
+	spin_lock(&pool->lock);
+	zhdr = handle_to_zbud_header(handle);
+
+	/* If first buddy, handle will be page aligned */
+	if ((handle - ZHDR_SIZE_ALIGNED) & ~PAGE_MASK)
+		zhdr->last_chunks = 0;
+	else
+		zhdr->first_chunks = 0;
+
+	if (zhdr->under_reclaim) {
+		/* zbud page is under reclaim, reclaim will free */
+		spin_unlock(&pool->lock);
+		return;
+	}
+
+	/* Remove from existing buddy list */
+	list_del(&zhdr->buddy);
+
+	if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) {
+		/* zbud page is empty, free */
+		list_del(&zhdr->lru);
+		free_zbud_page(zhdr);
+		pool->pages_nr--;
+	} else {
+		/* Add to unbuddied list */
+		freechunks = num_free_chunks(zhdr);
+		list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
+	}
+
+	spin_unlock(&pool->lock);
+}
+
+#define list_tail_entry(ptr, type, member) \
+	list_entry((ptr)->prev, type, member)
+
+/**
+ * zbud_reclaim_page() - evicts allocations from a pool page and frees it
+ * @pool:	pool from which a page will attempt to be evicted
+ * @retires:	number of pages on the LRU list for which eviction will
+ *		be attempted before failing
+ *
+ * zbud reclaim is different from normal system reclaim in that the reclaim is
+ * done from the bottom, up.  This is because only the bottom layer, zbud, has
+ * information on how the allocations are organized within each zbud page. This
+ * has the potential to create interesting locking situations between zbud and
+ * the user, however.
+ *
+ * To avoid these, this is how zbud_reclaim_page() should be called:
+
+ * The user detects a page should be reclaimed and calls zbud_reclaim_page().
+ * zbud_reclaim_page() will remove a zbud page from the pool LRU list and call
+ * the user-defined eviction handler with the pool and handle as arguments.
+ *
+ * If the handle can not be evicted, the eviction handler should return
+ * non-zero. zbud_reclaim_page() will add the zbud page back to the
+ * appropriate list and try the next zbud page on the LRU up to
+ * a user defined number of retries.
+ *
+ * If the handle is successfully evicted, the eviction handler should
+ * return 0 _and_ should have called zbud_free() on the handle. zbud_free()
+ * contains logic to delay freeing the page if the page is under reclaim,
+ * as indicated by the setting of the PG_reclaim flag on the underlying page.
+ *
+ * If all buddies in the zbud page are successfully evicted, then the
+ * zbud page can be freed.
+ *
+ * Returns: 0 if page is successfully freed, otherwise -EINVAL if there are
+ * no pages to evict or an eviction handler is not registered, -EAGAIN if
+ * the retry limit was hit.
+ */
+int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
+{
+	int i, ret, freechunks;
+	struct zbud_header *zhdr;
+	unsigned long first_handle = 0, last_handle = 0;
+
+	spin_lock(&pool->lock);
+	if (!pool->ops || !pool->ops->evict || list_empty(&pool->lru) ||
+			retries == 0) {
+		spin_unlock(&pool->lock);
+		return -EINVAL;
+	}
+	for (i = 0; i < retries; i++) {
+		zhdr = list_tail_entry(&pool->lru, struct zbud_header, lru);
+		list_del(&zhdr->lru);
+		list_del(&zhdr->buddy);
+		/* Protect zbud page against free */
+		zhdr->under_reclaim = true;
+		/*
+		 * We need encode the handles before unlocking, since we can
+		 * race with free that will set (first|last)_chunks to 0
+		 */
+		first_handle = 0;
+		last_handle = 0;
+		if (zhdr->first_chunks)
+			first_handle = encode_handle(zhdr, FIRST);
+		if (zhdr->last_chunks)
+			last_handle = encode_handle(zhdr, LAST);
+		spin_unlock(&pool->lock);
+
+		/* Issue the eviction callback(s) */
+		if (first_handle) {
+			ret = pool->ops->evict(pool, first_handle);
+			if (ret)
+				goto next;
+		}
+		if (last_handle) {
+			ret = pool->ops->evict(pool, last_handle);
+			if (ret)
+				goto next;
+		}
+next:
+		spin_lock(&pool->lock);
+		zhdr->under_reclaim = false;
+		if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) {
+			/*
+			 * Both buddies are now free, free the zbud page and
+			 * return success.
+			 */
+			free_zbud_page(zhdr);
+			pool->pages_nr--;
+			spin_unlock(&pool->lock);
+			return 0;
+		} else if (zhdr->first_chunks == 0 ||
+				zhdr->last_chunks == 0) {
+			/* add to unbuddied list */
+			freechunks = num_free_chunks(zhdr);
+			list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
+		} else {
+			/* add to buddied list */
+			list_add(&zhdr->buddy, &pool->buddied);
+		}
+
+		/* add to beginning of LRU */
+		list_add(&zhdr->lru, &pool->lru);
+	}
+	spin_unlock(&pool->lock);
+	return -EAGAIN;
+}
+
+/**
+ * zbud_map() - maps the allocation associated with the given handle
+ * @pool:	pool in which the allocation resides
+ * @handle:	handle associated with the allocation to be mapped
+ *
+ * While trivial for zbud, the mapping functions for others allocators
+ * implementing this allocation API could have more complex information encoded
+ * in the handle and could create temporary mappings to make the data
+ * accessible to the user.
+ *
+ * Returns: a pointer to the mapped allocation
+ */
+void *zbud_map(struct zbud_pool *pool, unsigned long handle)
+{
+	return (void *)(handle);
+}
+
+/**
+ * zbud_unmap() - maps the allocation associated with the given handle
+ * @pool:	pool in which the allocation resides
+ * @handle:	handle associated with the allocation to be unmapped
+ */
+void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
+{
+}
+
+/**
+ * zbud_get_pool_size() - gets the zbud pool size in pages
+ * @pool:	pool whose size is being queried
+ *
+ * Returns: size in pages of the given pool.  The pool lock need not be
+ * taken to access pages_nr.
+ */
+u64 zbud_get_pool_size(struct zbud_pool *pool)
+{
+	return pool->pages_nr;
+}
+
+static int __init init_zbud(void)
+{
+	/* Make sure the zbud header will fit in one chunk */
+	BUILD_BUG_ON(sizeof(struct zbud_header) > ZHDR_SIZE_ALIGNED);
+	pr_info("loaded\n");
+	return 0;
+}
+
+static void __exit exit_zbud(void)
+{
+	pr_info("unloaded\n");
+}
+
+module_init(init_zbud);
+module_exit(exit_zbud);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Seth Jennings <sjenning@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("Buddy Allocator for Compressed Pages");
diff --git a/mm/zswap.c b/mm/zswap.c
new file mode 100644
index 00000000000..deda2b671e1
--- /dev/null
+++ b/mm/zswap.c
@@ -0,0 +1,943 @@
+/*
+ * zswap.c - zswap driver file
+ *
+ * zswap is a backend for frontswap that takes pages that are in the process
+ * of being swapped out and attempts to compress and store them in a
+ * RAM-based memory pool.  This can result in a significant I/O reduction on
+ * the swap device and, in the case where decompressing from RAM is faster
+ * than reading from the swap device, can also improve workload performance.
+ *
+ * Copyright (C) 2012  Seth Jennings <sjenning@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/cpu.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/atomic.h>
+#include <linux/frontswap.h>
+#include <linux/rbtree.h>
+#include <linux/swap.h>
+#include <linux/crypto.h>
+#include <linux/mempool.h>
+#include <linux/zbud.h>
+
+#include <linux/mm_types.h>
+#include <linux/page-flags.h>
+#include <linux/swapops.h>
+#include <linux/writeback.h>
+#include <linux/pagemap.h>
+
+/*********************************
+* statistics
+**********************************/
+/* Number of memory pages used by the compressed pool */
+static u64 zswap_pool_pages;
+/* The number of compressed pages currently stored in zswap */
+static atomic_t zswap_stored_pages = ATOMIC_INIT(0);
+
+/*
+ * The statistics below are not protected from concurrent access for
+ * performance reasons so they may not be a 100% accurate.  However,
+ * they do provide useful information on roughly how many times a
+ * certain event is occurring.
+*/
+
+/* Pool limit was hit (see zswap_max_pool_percent) */
+static u64 zswap_pool_limit_hit;
+/* Pages written back when pool limit was reached */
+static u64 zswap_written_back_pages;
+/* Store failed due to a reclaim failure after pool limit was reached */
+static u64 zswap_reject_reclaim_fail;
+/* Compressed page was too big for the allocator to (optimally) store */
+static u64 zswap_reject_compress_poor;
+/* Store failed because underlying allocator could not get memory */
+static u64 zswap_reject_alloc_fail;
+/* Store failed because the entry metadata could not be allocated (rare) */
+static u64 zswap_reject_kmemcache_fail;
+/* Duplicate store was encountered (rare) */
+static u64 zswap_duplicate_entry;
+
+/*********************************
+* tunables
+**********************************/
+/* Enable/disable zswap (disabled by default, fixed at boot for now) */
+static bool zswap_enabled __read_mostly;
+module_param_named(enabled, zswap_enabled, bool, 0);
+
+/* Compressor to be used by zswap (fixed at boot for now) */
+#define ZSWAP_COMPRESSOR_DEFAULT "lzo"
+static char *zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT;
+module_param_named(compressor, zswap_compressor, charp, 0);
+
+/* The maximum percentage of memory that the compressed pool can occupy */
+static unsigned int zswap_max_pool_percent = 20;
+module_param_named(max_pool_percent,
+			zswap_max_pool_percent, uint, 0644);
+
+/*********************************
+* compression functions
+**********************************/
+/* per-cpu compression transforms */
+static struct crypto_comp * __percpu *zswap_comp_pcpu_tfms;
+
+enum comp_op {
+	ZSWAP_COMPOP_COMPRESS,
+	ZSWAP_COMPOP_DECOMPRESS
+};
+
+static int zswap_comp_op(enum comp_op op, const u8 *src, unsigned int slen,
+				u8 *dst, unsigned int *dlen)
+{
+	struct crypto_comp *tfm;
+	int ret;
+
+	tfm = *per_cpu_ptr(zswap_comp_pcpu_tfms, get_cpu());
+	switch (op) {
+	case ZSWAP_COMPOP_COMPRESS:
+		ret = crypto_comp_compress(tfm, src, slen, dst, dlen);
+		break;
+	case ZSWAP_COMPOP_DECOMPRESS:
+		ret = crypto_comp_decompress(tfm, src, slen, dst, dlen);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	put_cpu();
+	return ret;
+}
+
+static int __init zswap_comp_init(void)
+{
+	if (!crypto_has_comp(zswap_compressor, 0, 0)) {
+		pr_info("%s compressor not available\n", zswap_compressor);
+		/* fall back to default compressor */
+		zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT;
+		if (!crypto_has_comp(zswap_compressor, 0, 0))
+			/* can't even load the default compressor */
+			return -ENODEV;
+	}
+	pr_info("using %s compressor\n", zswap_compressor);
+
+	/* alloc percpu transforms */
+	zswap_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *);
+	if (!zswap_comp_pcpu_tfms)
+		return -ENOMEM;
+	return 0;
+}
+
+static void zswap_comp_exit(void)
+{
+	/* free percpu transforms */
+	if (zswap_comp_pcpu_tfms)
+		free_percpu(zswap_comp_pcpu_tfms);
+}
+
+/*********************************
+* data structures
+**********************************/
+/*
+ * struct zswap_entry
+ *
+ * This structure contains the metadata for tracking a single compressed
+ * page within zswap.
+ *
+ * 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
+ *            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
+ * length - the length in bytes of the compressed page data.  Needed during
+ *           decompression
+ */
+struct zswap_entry {
+	struct rb_node rbnode;
+	pgoff_t offset;
+	int refcount;
+	unsigned int length;
+	unsigned long handle;
+};
+
+struct zswap_header {
+	swp_entry_t swpentry;
+};
+
+/*
+ * The tree lock in the zswap_tree struct protects a few things:
+ * - the rbtree
+ * - the refcount field of each entry in the tree
+ */
+struct zswap_tree {
+	struct rb_root rbroot;
+	spinlock_t lock;
+	struct zbud_pool *pool;
+};
+
+static struct zswap_tree *zswap_trees[MAX_SWAPFILES];
+
+/*********************************
+* zswap entry functions
+**********************************/
+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);
+}
+
+static void zswap_entry_cache_destory(void)
+{
+	kmem_cache_destroy(zswap_entry_cache);
+}
+
+static struct zswap_entry *zswap_entry_cache_alloc(gfp_t gfp)
+{
+	struct zswap_entry *entry;
+	entry = kmem_cache_alloc(zswap_entry_cache, gfp);
+	if (!entry)
+		return NULL;
+	entry->refcount = 1;
+	return entry;
+}
+
+static void zswap_entry_cache_free(struct zswap_entry *entry)
+{
+	kmem_cache_free(zswap_entry_cache, entry);
+}
+
+/* caller must hold the tree lock */
+static void zswap_entry_get(struct zswap_entry *entry)
+{
+	entry->refcount++;
+}
+
+/* caller must hold the tree lock */
+static int zswap_entry_put(struct zswap_entry *entry)
+{
+	entry->refcount--;
+	return entry->refcount;
+}
+
+/*********************************
+* rbtree functions
+**********************************/
+static struct zswap_entry *zswap_rb_search(struct rb_root *root, pgoff_t offset)
+{
+	struct rb_node *node = root->rb_node;
+	struct zswap_entry *entry;
+
+	while (node) {
+		entry = rb_entry(node, struct zswap_entry, rbnode);
+		if (entry->offset > offset)
+			node = node->rb_left;
+		else if (entry->offset < offset)
+			node = node->rb_right;
+		else
+			return entry;
+	}
+	return NULL;
+}
+
+/*
+ * In the case that a entry with the same offset is found, a pointer to
+ * the existing entry is stored in dupentry and the function returns -EEXIST
+ */
+static int zswap_rb_insert(struct rb_root *root, struct zswap_entry *entry,
+			struct zswap_entry **dupentry)
+{
+	struct rb_node **link = &root->rb_node, *parent = NULL;
+	struct zswap_entry *myentry;
+
+	while (*link) {
+		parent = *link;
+		myentry = rb_entry(parent, struct zswap_entry, rbnode);
+		if (myentry->offset > entry->offset)
+			link = &(*link)->rb_left;
+		else if (myentry->offset < entry->offset)
+			link = &(*link)->rb_right;
+		else {
+			*dupentry = myentry;
+			return -EEXIST;
+		}
+	}
+	rb_link_node(&entry->rbnode, parent, link);
+	rb_insert_color(&entry->rbnode, root);
+	return 0;
+}
+
+/*********************************
+* per-cpu code
+**********************************/
+static DEFINE_PER_CPU(u8 *, zswap_dstmem);
+
+static int __zswap_cpu_notifier(unsigned long action, unsigned long cpu)
+{
+	struct crypto_comp *tfm;
+	u8 *dst;
+
+	switch (action) {
+	case CPU_UP_PREPARE:
+		tfm = crypto_alloc_comp(zswap_compressor, 0, 0);
+		if (IS_ERR(tfm)) {
+			pr_err("can't allocate compressor transform\n");
+			return NOTIFY_BAD;
+		}
+		*per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = tfm;
+		dst = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
+		if (!dst) {
+			pr_err("can't allocate compressor buffer\n");
+			crypto_free_comp(tfm);
+			*per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = NULL;
+			return NOTIFY_BAD;
+		}
+		per_cpu(zswap_dstmem, cpu) = dst;
+		break;
+	case CPU_DEAD:
+	case CPU_UP_CANCELED:
+		tfm = *per_cpu_ptr(zswap_comp_pcpu_tfms, cpu);
+		if (tfm) {
+			crypto_free_comp(tfm);
+			*per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = NULL;
+		}
+		dst = per_cpu(zswap_dstmem, cpu);
+		kfree(dst);
+		per_cpu(zswap_dstmem, cpu) = NULL;
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static int zswap_cpu_notifier(struct notifier_block *nb,
+				unsigned long action, void *pcpu)
+{
+	unsigned long cpu = (unsigned long)pcpu;
+	return __zswap_cpu_notifier(action, cpu);
+}
+
+static struct notifier_block zswap_cpu_notifier_block = {
+	.notifier_call = zswap_cpu_notifier
+};
+
+static int zswap_cpu_init(void)
+{
+	unsigned long cpu;
+
+	get_online_cpus();
+	for_each_online_cpu(cpu)
+		if (__zswap_cpu_notifier(CPU_UP_PREPARE, cpu) != NOTIFY_OK)
+			goto cleanup;
+	register_cpu_notifier(&zswap_cpu_notifier_block);
+	put_online_cpus();
+	return 0;
+
+cleanup:
+	for_each_online_cpu(cpu)
+		__zswap_cpu_notifier(CPU_UP_CANCELED, cpu);
+	put_online_cpus();
+	return -ENOMEM;
+}
+
+/*********************************
+* helpers
+**********************************/
+static bool zswap_is_full(void)
+{
+	return (totalram_pages * zswap_max_pool_percent / 100 <
+		zswap_pool_pages);
+}
+
+/*
+ * Carries out the common pattern of freeing and entry's zsmalloc 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)
+{
+	zbud_free(tree->pool, entry->handle);
+	zswap_entry_cache_free(entry);
+	atomic_dec(&zswap_stored_pages);
+	zswap_pool_pages = zbud_get_pool_size(tree->pool);
+}
+
+/*********************************
+* writeback code
+**********************************/
+/* return enum for zswap_get_swap_cache_page */
+enum zswap_get_swap_ret {
+	ZSWAP_SWAPCACHE_NEW,
+	ZSWAP_SWAPCACHE_EXIST,
+	ZSWAP_SWAPCACHE_NOMEM
+};
+
+/*
+ * zswap_get_swap_cache_page
+ *
+ * This is an adaption of read_swap_cache_async()
+ *
+ * This function tries to find a page with the given swap entry
+ * in the swapper_space address space (the swap cache).  If the page
+ * is found, it is returned in retpage.  Otherwise, a page is allocated,
+ * added to the swap cache, and returned in retpage.
+ *
+ * If success, the swap cache page is returned in retpage
+ * Returns 0 if page was already in the swap cache, page is not locked
+ * Returns 1 if the new page needs to be populated, page is locked
+ * Returns <0 on error
+ */
+static int zswap_get_swap_cache_page(swp_entry_t entry,
+				struct page **retpage)
+{
+	struct page *found_page, *new_page = NULL;
+	struct address_space *swapper_space = &swapper_spaces[swp_type(entry)];
+	int err;
+
+	*retpage = NULL;
+	do {
+		/*
+		 * First check the swap cache.  Since this is normally
+		 * called after lookup_swap_cache() failed, re-calling
+		 * that would confuse statistics.
+		 */
+		found_page = find_get_page(swapper_space, entry.val);
+		if (found_page)
+			break;
+
+		/*
+		 * Get a new page to read into from swap.
+		 */
+		if (!new_page) {
+			new_page = alloc_page(GFP_KERNEL);
+			if (!new_page)
+				break; /* Out of memory */
+		}
+
+		/*
+		 * call radix_tree_preload() while we can wait.
+		 */
+		err = radix_tree_preload(GFP_KERNEL);
+		if (err)
+			break;
+
+		/*
+		 * Swap entry may have been freed since our caller observed it.
+		 */
+		err = swapcache_prepare(entry);
+		if (err == -EEXIST) { /* seems racy */
+			radix_tree_preload_end();
+			continue;
+		}
+		if (err) { /* swp entry is obsolete ? */
+			radix_tree_preload_end();
+			break;
+		}
+
+		/* May fail (-ENOMEM) if radix-tree node allocation failed. */
+		__set_page_locked(new_page);
+		SetPageSwapBacked(new_page);
+		err = __add_to_swap_cache(new_page, entry);
+		if (likely(!err)) {
+			radix_tree_preload_end();
+			lru_cache_add_anon(new_page);
+			*retpage = new_page;
+			return ZSWAP_SWAPCACHE_NEW;
+		}
+		radix_tree_preload_end();
+		ClearPageSwapBacked(new_page);
+		__clear_page_locked(new_page);
+		/*
+		 * add_to_swap_cache() doesn't return -EEXIST, so we can safely
+		 * clear SWAP_HAS_CACHE flag.
+		 */
+		swapcache_free(entry, NULL);
+	} while (err != -ENOMEM);
+
+	if (new_page)
+		page_cache_release(new_page);
+	if (!found_page)
+		return ZSWAP_SWAPCACHE_NOMEM;
+	*retpage = found_page;
+	return ZSWAP_SWAPCACHE_EXIST;
+}
+
+/*
+ * Attempts to free an entry by adding a page to the swap cache,
+ * decompressing the entry data into the page, and issuing a
+ * bio write to write the page back to the swap device.
+ *
+ * This can be thought of as a "resumed writeback" of the page
+ * to the swap device.  We are basically resuming the same swap
+ * writeback path that was intercepted with the frontswap_store()
+ * in the first place.  After the page has been decompressed into
+ * the swap cache, the compressed version stored by zswap can be
+ * freed.
+ */
+static int zswap_writeback_entry(struct zbud_pool *pool, unsigned long handle)
+{
+	struct zswap_header *zhdr;
+	swp_entry_t swpentry;
+	struct zswap_tree *tree;
+	pgoff_t offset;
+	struct zswap_entry *entry;
+	struct page *page;
+	u8 *src, *dst;
+	unsigned int dlen;
+	int ret, refcount;
+	struct writeback_control wbc = {
+		.sync_mode = WB_SYNC_NONE,
+	};
+
+	/* extract swpentry from data */
+	zhdr = zbud_map(pool, handle);
+	swpentry = zhdr->swpentry; /* here */
+	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);
+	entry = zswap_rb_search(&tree->rbroot, offset);
+	if (!entry) {
+		/* entry was invalidated */
+		spin_unlock(&tree->lock);
+		return 0;
+	}
+	zswap_entry_get(entry);
+	spin_unlock(&tree->lock);
+	BUG_ON(offset != entry->offset);
+
+	/* try to allocate swap cache page */
+	switch (zswap_get_swap_cache_page(swpentry, &page)) {
+	case ZSWAP_SWAPCACHE_NOMEM: /* no memory */
+		ret = -ENOMEM;
+		goto fail;
+
+	case ZSWAP_SWAPCACHE_EXIST: /* page is unlocked */
+		/* page is already in the swap cache, ignore for now */
+		page_cache_release(page);
+		ret = -EEXIST;
+		goto fail;
+
+	case ZSWAP_SWAPCACHE_NEW: /* page is locked */
+		/* decompress */
+		dlen = PAGE_SIZE;
+		src = (u8 *)zbud_map(tree->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);
+		BUG_ON(ret);
+		BUG_ON(dlen != PAGE_SIZE);
+
+		/* page is up to date */
+		SetPageUptodate(page);
+	}
+
+	/* start writeback */
+	__swap_writepage(page, &wbc, end_swap_bio_write);
+	page_cache_release(page);
+	zswap_written_back_pages++;
+
+	spin_lock(&tree->lock);
+
+	/* drop local reference */
+	zswap_entry_put(entry);
+	/* drop the initial reference from entry creation */
+	refcount = zswap_entry_put(entry);
+
+	/*
+	 * There are three possible values for refcount here:
+	 * (1) refcount is 1, load is in progress, unlink from rbtree,
+	 *     load will free
+	 * (2) refcount is 0, (normal case) entry is valid,
+	 *     remove from rbtree and free entry
+	 * (3) refcount is -1, invalidate happened during writeback,
+	 *     free entry
+	 */
+	if (refcount >= 0) {
+		/* no invalidate yet, remove from rbtree */
+		rb_erase(&entry->rbnode, &tree->rbroot);
+	}
+	spin_unlock(&tree->lock);
+	if (refcount <= 0) {
+		/* free the entry */
+		zswap_free_entry(tree, entry);
+		return 0;
+	}
+	return -EAGAIN;
+
+fail:
+	spin_lock(&tree->lock);
+	zswap_entry_put(entry);
+	spin_unlock(&tree->lock);
+	return ret;
+}
+
+/*********************************
+* frontswap hooks
+**********************************/
+/* attempts to compress and store an single page */
+static int zswap_frontswap_store(unsigned type, pgoff_t offset,
+				struct page *page)
+{
+	struct zswap_tree *tree = zswap_trees[type];
+	struct zswap_entry *entry, *dupentry;
+	int ret;
+	unsigned int dlen = PAGE_SIZE, len;
+	unsigned long handle;
+	char *buf;
+	u8 *src, *dst;
+	struct zswap_header *zhdr;
+
+	if (!tree) {
+		ret = -ENODEV;
+		goto reject;
+	}
+
+	/* reclaim space if needed */
+	if (zswap_is_full()) {
+		zswap_pool_limit_hit++;
+		if (zbud_reclaim_page(tree->pool, 8)) {
+			zswap_reject_reclaim_fail++;
+			ret = -ENOMEM;
+			goto reject;
+		}
+	}
+
+	/* allocate entry */
+	entry = zswap_entry_cache_alloc(GFP_KERNEL);
+	if (!entry) {
+		zswap_reject_kmemcache_fail++;
+		ret = -ENOMEM;
+		goto reject;
+	}
+
+	/* compress */
+	dst = get_cpu_var(zswap_dstmem);
+	src = kmap_atomic(page);
+	ret = zswap_comp_op(ZSWAP_COMPOP_COMPRESS, src, PAGE_SIZE, dst, &dlen);
+	kunmap_atomic(src);
+	if (ret) {
+		ret = -EINVAL;
+		goto freepage;
+	}
+
+	/* store */
+	len = dlen + sizeof(struct zswap_header);
+	ret = zbud_alloc(tree->pool, len, __GFP_NORETRY | __GFP_NOWARN,
+		&handle);
+	if (ret == -ENOSPC) {
+		zswap_reject_compress_poor++;
+		goto freepage;
+	}
+	if (ret) {
+		zswap_reject_alloc_fail++;
+		goto freepage;
+	}
+	zhdr = zbud_map(tree->pool, handle);
+	zhdr->swpentry = swp_entry(type, offset);
+	buf = (u8 *)(zhdr + 1);
+	memcpy(buf, dst, dlen);
+	zbud_unmap(tree->pool, handle);
+	put_cpu_var(zswap_dstmem);
+
+	/* populate entry */
+	entry->offset = offset;
+	entry->handle = handle;
+	entry->length = dlen;
+
+	/* map */
+	spin_lock(&tree->lock);
+	do {
+		ret = zswap_rb_insert(&tree->rbroot, entry, &dupentry);
+		if (ret == -EEXIST) {
+			zswap_duplicate_entry++;
+			/* remove from rbtree */
+			rb_erase(&dupentry->rbnode, &tree->rbroot);
+			if (!zswap_entry_put(dupentry)) {
+				/* free */
+				zswap_free_entry(tree, dupentry);
+			}
+		}
+	} while (ret == -EEXIST);
+	spin_unlock(&tree->lock);
+
+	/* update stats */
+	atomic_inc(&zswap_stored_pages);
+	zswap_pool_pages = zbud_get_pool_size(tree->pool);
+
+	return 0;
+
+freepage:
+	put_cpu_var(zswap_dstmem);
+	zswap_entry_cache_free(entry);
+reject:
+	return ret;
+}
+
+/*
+ * returns 0 if the page was successfully decompressed
+ * return -1 on entry not found or error
+*/
+static int zswap_frontswap_load(unsigned type, pgoff_t offset,
+				struct page *page)
+{
+	struct zswap_tree *tree = zswap_trees[type];
+	struct zswap_entry *entry;
+	u8 *src, *dst;
+	unsigned int dlen;
+	int refcount, ret;
+
+	/* find */
+	spin_lock(&tree->lock);
+	entry = zswap_rb_search(&tree->rbroot, offset);
+	if (!entry) {
+		/* entry was written back */
+		spin_unlock(&tree->lock);
+		return -1;
+	}
+	zswap_entry_get(entry);
+	spin_unlock(&tree->lock);
+
+	/* decompress */
+	dlen = PAGE_SIZE;
+	src = (u8 *)zbud_map(tree->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);
+	BUG_ON(ret);
+
+	spin_lock(&tree->lock);
+	refcount = zswap_entry_put(entry);
+	if (likely(refcount)) {
+		spin_unlock(&tree->lock);
+		return 0;
+	}
+	spin_unlock(&tree->lock);
+
+	/*
+	 * We don't have to unlink from the rbtree because
+	 * zswap_writeback_entry() or zswap_frontswap_invalidate page()
+	 * has already done this for us if we are the last reference.
+	 */
+	/* free */
+
+	zswap_free_entry(tree, entry);
+
+	return 0;
+}
+
+/* frees an entry in zswap */
+static void zswap_frontswap_invalidate_page(unsigned type, pgoff_t offset)
+{
+	struct zswap_tree *tree = zswap_trees[type];
+	struct zswap_entry *entry;
+	int refcount;
+
+	/* find */
+	spin_lock(&tree->lock);
+	entry = zswap_rb_search(&tree->rbroot, offset);
+	if (!entry) {
+		/* entry was written back */
+		spin_unlock(&tree->lock);
+		return;
+	}
+
+	/* remove from rbtree */
+	rb_erase(&entry->rbnode, &tree->rbroot);
+
+	/* drop the initial reference from entry creation */
+	refcount = zswap_entry_put(entry);
+
+	spin_unlock(&tree->lock);
+
+	if (refcount) {
+		/* writeback in progress, writeback will free */
+		return;
+	}
+
+	/* free */
+	zswap_free_entry(tree, entry);
+}
+
+/* frees all zswap entries for the given swap type */
+static void zswap_frontswap_invalidate_area(unsigned type)
+{
+	struct zswap_tree *tree = zswap_trees[type];
+	struct rb_node *node;
+	struct zswap_entry *entry;
+
+	if (!tree)
+		return;
+
+	/* walk the tree and free everything */
+	spin_lock(&tree->lock);
+	/*
+	 * TODO: Even though this code should not be executed because
+	 * the try_to_unuse() in swapoff should have emptied the tree,
+	 * it is very wasteful to rebalance the tree after every
+	 * removal when we are freeing the whole tree.
+	 *
+	 * If post-order traversal code is ever added to the rbtree
+	 * implementation, it should be used here.
+	 */
+	while ((node = rb_first(&tree->rbroot))) {
+		entry = rb_entry(node, struct zswap_entry, rbnode);
+		rb_erase(&entry->rbnode, &tree->rbroot);
+		zbud_free(tree->pool, entry->handle);
+		zswap_entry_cache_free(entry);
+		atomic_dec(&zswap_stored_pages);
+	}
+	tree->rbroot = RB_ROOT;
+	spin_unlock(&tree->lock);
+}
+
+static struct zbud_ops zswap_zbud_ops = {
+	.evict = zswap_writeback_entry
+};
+
+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;
+	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 = {
+	.store = zswap_frontswap_store,
+	.load = zswap_frontswap_load,
+	.invalidate_page = zswap_frontswap_invalidate_page,
+	.invalidate_area = zswap_frontswap_invalidate_area,
+	.init = zswap_frontswap_init
+};
+
+/*********************************
+* debugfs functions
+**********************************/
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+
+static struct dentry *zswap_debugfs_root;
+
+static int __init zswap_debugfs_init(void)
+{
+	if (!debugfs_initialized())
+		return -ENODEV;
+
+	zswap_debugfs_root = debugfs_create_dir("zswap", NULL);
+	if (!zswap_debugfs_root)
+		return -ENOMEM;
+
+	debugfs_create_u64("pool_limit_hit", S_IRUGO,
+			zswap_debugfs_root, &zswap_pool_limit_hit);
+	debugfs_create_u64("reject_reclaim_fail", S_IRUGO,
+			zswap_debugfs_root, &zswap_reject_reclaim_fail);
+	debugfs_create_u64("reject_alloc_fail", S_IRUGO,
+			zswap_debugfs_root, &zswap_reject_alloc_fail);
+	debugfs_create_u64("reject_kmemcache_fail", S_IRUGO,
+			zswap_debugfs_root, &zswap_reject_kmemcache_fail);
+	debugfs_create_u64("reject_compress_poor", S_IRUGO,
+			zswap_debugfs_root, &zswap_reject_compress_poor);
+	debugfs_create_u64("written_back_pages", S_IRUGO,
+			zswap_debugfs_root, &zswap_written_back_pages);
+	debugfs_create_u64("duplicate_entry", S_IRUGO,
+			zswap_debugfs_root, &zswap_duplicate_entry);
+	debugfs_create_u64("pool_pages", S_IRUGO,
+			zswap_debugfs_root, &zswap_pool_pages);
+	debugfs_create_atomic_t("stored_pages", S_IRUGO,
+			zswap_debugfs_root, &zswap_stored_pages);
+
+	return 0;
+}
+
+static void __exit zswap_debugfs_exit(void)
+{
+	debugfs_remove_recursive(zswap_debugfs_root);
+}
+#else
+static int __init zswap_debugfs_init(void)
+{
+	return 0;
+}
+
+static void __exit zswap_debugfs_exit(void) { }
+#endif
+
+/*********************************
+* module init and exit
+**********************************/
+static int __init init_zswap(void)
+{
+	if (!zswap_enabled)
+		return 0;
+
+	pr_info("loading zswap\n");
+	if (zswap_entry_cache_create()) {
+		pr_err("entry cache creation failed\n");
+		goto error;
+	}
+	if (zswap_comp_init()) {
+		pr_err("compressor initialization failed\n");
+		goto compfail;
+	}
+	if (zswap_cpu_init()) {
+		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");
+	return 0;
+pcpufail:
+	zswap_comp_exit();
+compfail:
+	zswap_entry_cache_destory();
+error:
+	return -ENOMEM;
+}
+/* must be late so crypto has time to come up */
+late_initcall(init_zswap);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Seth Jennings <sjenning@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("Compressed cache for swap pages");