Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:

 - a few misc bits

 - ocfs2

 - most(?) of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (125 commits)
  thp: fix comments of __pmd_trans_huge_lock()
  cgroup: remove unnecessary 0 check from css_from_id()
  cgroup: fix idr leak for the first cgroup root
  mm: memcontrol: fix documentation for compound parameter
  mm: memcontrol: remove BUG_ON in uncharge_list
  mm: fix build warnings in <linux/compaction.h>
  mm, thp: convert from optimistic swapin collapsing to conservative
  mm, thp: fix comment inconsistency for swapin readahead functions
  thp: update Documentation/{vm/transhuge,filesystems/proc}.txt
  shmem: split huge pages beyond i_size under memory pressure
  thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE
  khugepaged: add support of collapse for tmpfs/shmem pages
  shmem: make shmem_inode_info::lock irq-safe
  khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page()
  thp: extract khugepaged from mm/huge_memory.c
  shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings
  shmem: add huge pages support
  shmem: get_unmapped_area align huge page
  shmem: prepare huge= mount option and sysfs knob
  mm, rmap: account shmem thp pages
  ...

1 files changed, 89 insertions, 45 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5339c89dff63..f3a84c64f35c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1259,6 +1259,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
 	struct oom_control oc = {
 		.zonelist = NULL,
 		.nodemask = NULL,
+		.memcg = memcg,
 		.gfp_mask = gfp_mask,
 		.order = order,
 	};
@@ -1281,7 +1282,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
 		goto unlock;
 	}
 
-	check_panic_on_oom(&oc, CONSTRAINT_MEMCG, memcg);
+	check_panic_on_oom(&oc, CONSTRAINT_MEMCG);
 	totalpages = mem_cgroup_get_limit(memcg) ? : 1;
 	for_each_mem_cgroup_tree(iter, memcg) {
 		struct css_task_iter it;
@@ -1289,7 +1290,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
 
 		css_task_iter_start(&iter->css, &it);
 		while ((task = css_task_iter_next(&it))) {
-			switch (oom_scan_process_thread(&oc, task, totalpages)) {
+			switch (oom_scan_process_thread(&oc, task)) {
 			case OOM_SCAN_SELECT:
 				if (chosen)
 					put_task_struct(chosen);
@@ -1329,7 +1330,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
 
 	if (chosen) {
 		points = chosen_points * 1000 / totalpages;
-		oom_kill_process(&oc, chosen, points, totalpages, memcg,
+		oom_kill_process(&oc, chosen, points, totalpages,
 				 "Memory cgroup out of memory");
 	}
 unlock:
@@ -2272,20 +2273,30 @@ static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
 	current->memcg_kmem_skip_account = 0;
 }
 
-/*
+static inline bool memcg_kmem_bypass(void)
+{
+	if (in_interrupt() || !current->mm || (current->flags & PF_KTHREAD))
+		return true;
+	return false;
+}
+
+/**
+ * memcg_kmem_get_cache: select the correct per-memcg cache for allocation
+ * @cachep: the original global kmem cache
+ *
  * Return the kmem_cache we're supposed to use for a slab allocation.
  * We try to use the current memcg's version of the cache.
  *
- * If the cache does not exist yet, if we are the first user of it,
- * we either create it immediately, if possible, or create it asynchronously
- * in a workqueue.
- * In the latter case, we will let the current allocation go through with
- * the original cache.
+ * If the cache does not exist yet, if we are the first user of it, we
+ * create it asynchronously in a workqueue and let the current allocation
+ * go through with the original cache.
  *
- * Can't be called in interrupt context or from kernel threads.
- * This function needs to be called with rcu_read_lock() held.
+ * This function takes a reference to the cache it returns to assure it
+ * won't get destroyed while we are working with it. Once the caller is
+ * done with it, memcg_kmem_put_cache() must be called to release the
+ * reference.
  */
-struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
+struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep)
 {
 	struct mem_cgroup *memcg;
 	struct kmem_cache *memcg_cachep;
@@ -2293,10 +2304,7 @@ struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 
 	VM_BUG_ON(!is_root_cache(cachep));
 
-	if (cachep->flags & SLAB_ACCOUNT)
-		gfp |= __GFP_ACCOUNT;
-
-	if (!(gfp & __GFP_ACCOUNT))
+	if (memcg_kmem_bypass())
 		return cachep;
 
 	if (current->memcg_kmem_skip_account)
@@ -2329,14 +2337,27 @@ out:
 	return cachep;
 }
 
-void __memcg_kmem_put_cache(struct kmem_cache *cachep)
+/**
+ * memcg_kmem_put_cache: drop reference taken by memcg_kmem_get_cache
+ * @cachep: the cache returned by memcg_kmem_get_cache
+ */
+void memcg_kmem_put_cache(struct kmem_cache *cachep)
 {
 	if (!is_root_cache(cachep))
 		css_put(&cachep->memcg_params.memcg->css);
 }
 
-int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
-			      struct mem_cgroup *memcg)
+/**
+ * memcg_kmem_charge: charge a kmem page
+ * @page: page to charge
+ * @gfp: reclaim mode
+ * @order: allocation order
+ * @memcg: memory cgroup to charge
+ *
+ * Returns 0 on success, an error code on failure.
+ */
+int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+			    struct mem_cgroup *memcg)
 {
 	unsigned int nr_pages = 1 << order;
 	struct page_counter *counter;
@@ -2357,19 +2378,34 @@ int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
 	return 0;
 }
 
-int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
+/**
+ * memcg_kmem_charge: charge a kmem page to the current memory cgroup
+ * @page: page to charge
+ * @gfp: reclaim mode
+ * @order: allocation order
+ *
+ * Returns 0 on success, an error code on failure.
+ */
+int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
 {
 	struct mem_cgroup *memcg;
 	int ret = 0;
 
+	if (memcg_kmem_bypass())
+		return 0;
+
 	memcg = get_mem_cgroup_from_mm(current->mm);
 	if (!mem_cgroup_is_root(memcg))
-		ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg);
+		ret = memcg_kmem_charge_memcg(page, gfp, order, memcg);
 	css_put(&memcg->css);
 	return ret;
 }
-
-void __memcg_kmem_uncharge(struct page *page, int order)
+/**
+ * memcg_kmem_uncharge: uncharge a kmem page
+ * @page: page to uncharge
+ * @order: allocation order
+ */
+void memcg_kmem_uncharge(struct page *page, int order)
 {
 	struct mem_cgroup *memcg = page->mem_cgroup;
 	unsigned int nr_pages = 1 << order;
@@ -4409,7 +4445,7 @@ static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
 
 #ifdef CONFIG_SWAP
 static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
-			unsigned long addr, pte_t ptent, swp_entry_t *entry)
+			pte_t ptent, swp_entry_t *entry)
 {
 	struct page *page = NULL;
 	swp_entry_t ent = pte_to_swp_entry(ptent);
@@ -4428,7 +4464,7 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
 }
 #else
 static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
-			unsigned long addr, pte_t ptent, swp_entry_t *entry)
+			pte_t ptent, swp_entry_t *entry)
 {
 	return NULL;
 }
@@ -4471,7 +4507,7 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
 /**
  * mem_cgroup_move_account - move account of the page
  * @page: the page
- * @nr_pages: number of regular pages (>1 for huge pages)
+ * @compound: charge the page as compound or small page
  * @from: mem_cgroup which the page is moved from.
  * @to:	mem_cgroup which the page is moved to. @from != @to.
  *
@@ -4593,7 +4629,7 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
 	if (pte_present(ptent))
 		page = mc_handle_present_pte(vma, addr, ptent);
 	else if (is_swap_pte(ptent))
-		page = mc_handle_swap_pte(vma, addr, ptent, &ent);
+		page = mc_handle_swap_pte(vma, ptent, &ent);
 	else if (pte_none(ptent))
 		page = mc_handle_file_pte(vma, addr, ptent, &ent);
 
@@ -5333,6 +5369,7 @@ bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg)
  * @mm: mm context of the victim
  * @gfp_mask: reclaim mode
  * @memcgp: charged memcg return
+ * @compound: charge the page as compound or small page
  *
  * Try to charge @page to the memcg that @mm belongs to, reclaiming
  * pages according to @gfp_mask if necessary.
@@ -5395,6 +5432,7 @@ out:
  * @page: page to charge
  * @memcg: memcg to charge the page to
  * @lrucare: page might be on LRU already
+ * @compound: charge the page as compound or small page
  *
  * Finalize a charge transaction started by mem_cgroup_try_charge(),
  * after page->mapping has been set up.  This must happen atomically
@@ -5446,6 +5484,7 @@ void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
  * mem_cgroup_cancel_charge - cancel a page charge
  * @page: page to charge
  * @memcg: memcg to charge the page to
+ * @compound: charge the page as compound or small page
  *
  * Cancel a charge transaction started by mem_cgroup_try_charge().
  */
@@ -5469,15 +5508,18 @@ void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg,
 
 static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,
 			   unsigned long nr_anon, unsigned long nr_file,
-			   unsigned long nr_huge, struct page *dummy_page)
+			   unsigned long nr_huge, unsigned long nr_kmem,
+			   struct page *dummy_page)
 {
-	unsigned long nr_pages = nr_anon + nr_file;
+	unsigned long nr_pages = nr_anon + nr_file + nr_kmem;
 	unsigned long flags;
 
 	if (!mem_cgroup_is_root(memcg)) {
 		page_counter_uncharge(&memcg->memory, nr_pages);
 		if (do_memsw_account())
 			page_counter_uncharge(&memcg->memsw, nr_pages);
+		if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && nr_kmem)
+			page_counter_uncharge(&memcg->kmem, nr_kmem);
 		memcg_oom_recover(memcg);
 	}
 
@@ -5500,6 +5542,7 @@ static void uncharge_list(struct list_head *page_list)
 	unsigned long nr_anon = 0;
 	unsigned long nr_file = 0;
 	unsigned long nr_huge = 0;
+	unsigned long nr_kmem = 0;
 	unsigned long pgpgout = 0;
 	struct list_head *next;
 	struct page *page;
@@ -5510,8 +5553,6 @@ static void uncharge_list(struct list_head *page_list)
 	 */
 	next = page_list->next;
 	do {
-		unsigned int nr_pages = 1;
-
 		page = list_entry(next, struct page, lru);
 		next = page->lru.next;
 
@@ -5530,31 +5571,34 @@ static void uncharge_list(struct list_head *page_list)
 		if (memcg != page->mem_cgroup) {
 			if (memcg) {
 				uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
-					       nr_huge, page);
-				pgpgout = nr_anon = nr_file = nr_huge = 0;
+					       nr_huge, nr_kmem, page);
+				pgpgout = nr_anon = nr_file =
+					nr_huge = nr_kmem = 0;
 			}
 			memcg = page->mem_cgroup;
 		}
 
-		if (PageTransHuge(page)) {
-			nr_pages <<= compound_order(page);
-			VM_BUG_ON_PAGE(!PageTransHuge(page), page);
-			nr_huge += nr_pages;
-		}
+		if (!PageKmemcg(page)) {
+			unsigned int nr_pages = 1;
 
-		if (PageAnon(page))
-			nr_anon += nr_pages;
-		else
-			nr_file += nr_pages;
+			if (PageTransHuge(page)) {
+				nr_pages <<= compound_order(page);
+				nr_huge += nr_pages;
+			}
+			if (PageAnon(page))
+				nr_anon += nr_pages;
+			else
+				nr_file += nr_pages;
+			pgpgout++;
+		} else
+			nr_kmem += 1 << compound_order(page);
 
 		page->mem_cgroup = NULL;
-
-		pgpgout++;
 	} while (next != page_list);
 
 	if (memcg)
 		uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
-			       nr_huge, page);
+			       nr_huge, nr_kmem, page);
 }
 
 /**