Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "Most of the rest of MM and various other things. Some Kconfig rework
  still awaits merges of dependent trees from linux-next.

  Subsystems affected by this patch series: mm/hotfixes, mm/memcg,
  mm/vmstat, mm/thp, procfs, sysctl, misc, notifiers, core-kernel,
  bitops, lib, checkpatch, epoll, binfmt, init, rapidio, uaccess, kcov,
  ubsan, ipc, bitmap, mm/pagemap"

* akpm: (86 commits)
  mm: remove __ARCH_HAS_4LEVEL_HACK and include/asm-generic/4level-fixup.h
  um: add support for folded p4d page tables
  um: remove unused pxx_offset_proc() and addr_pte() functions
  sparc32: use pgtable-nopud instead of 4level-fixup
  parisc/hugetlb: use pgtable-nopXd instead of 4level-fixup
  parisc: use pgtable-nopXd instead of 4level-fixup
  nds32: use pgtable-nopmd instead of 4level-fixup
  microblaze: use pgtable-nopmd instead of 4level-fixup
  m68k: mm: use pgtable-nopXd instead of 4level-fixup
  m68k: nommu: use pgtable-nopud instead of 4level-fixup
  c6x: use pgtable-nopud instead of 4level-fixup
  arm: nommu: use pgtable-nopud instead of 4level-fixup
  alpha: use pgtable-nopud instead of 4level-fixup
  gpio: pca953x: tighten up indentation
  gpio: pca953x: convert to use bitmap API
  gpio: pca953x: use input from regs structure in pca953x_irq_pending()
  gpio: pca953x: remove redundant variable and check in IRQ handler
  lib/bitmap: introduce bitmap_replace() helper
  lib/test_bitmap: fix comment about this file
  lib/test_bitmap: move exp1 and exp2 upper for others to use
  ...

5 files changed, 61 insertions, 74 deletions

diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index df3371d5c572..2fa710bb6358 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -36,6 +36,7 @@
 #include <linux/bug.h>
 #include <linux/uaccess.h>
 
+#include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
 #include "kasan.h"
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index bc01423277c5..c5b5f74cfd4d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -98,14 +98,6 @@ static bool do_memsw_account(void)
 	return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && do_swap_account;
 }
 
-static const char *const mem_cgroup_lru_names[] = {
-	"inactive_anon",
-	"active_anon",
-	"inactive_file",
-	"active_file",
-	"unevictable",
-};
-
 #define THRESHOLDS_EVENTS_TARGET 128
 #define SOFTLIMIT_EVENTS_TARGET 1024
 
@@ -1421,7 +1413,7 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
 		       PAGE_SIZE);
 
 	for (i = 0; i < NR_LRU_LISTS; i++)
-		seq_buf_printf(&s, "%s %llu\n", mem_cgroup_lru_names[i],
+		seq_buf_printf(&s, "%s %llu\n", lru_list_name(i),
 			       (u64)memcg_page_state(memcg, NR_LRU_BASE + i) *
 			       PAGE_SIZE);
 
@@ -1434,8 +1426,10 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
 
 	/* Accumulated memory events */
 
-	seq_buf_printf(&s, "pgfault %lu\n", memcg_events(memcg, PGFAULT));
-	seq_buf_printf(&s, "pgmajfault %lu\n", memcg_events(memcg, PGMAJFAULT));
+	seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGFAULT),
+		       memcg_events(memcg, PGFAULT));
+	seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGMAJFAULT),
+		       memcg_events(memcg, PGMAJFAULT));
 
 	seq_buf_printf(&s, "workingset_refault %lu\n",
 		       memcg_page_state(memcg, WORKINGSET_REFAULT));
@@ -1444,22 +1438,27 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
 	seq_buf_printf(&s, "workingset_nodereclaim %lu\n",
 		       memcg_page_state(memcg, WORKINGSET_NODERECLAIM));
 
-	seq_buf_printf(&s, "pgrefill %lu\n", memcg_events(memcg, PGREFILL));
+	seq_buf_printf(&s, "%s %lu\n",  vm_event_name(PGREFILL),
+		       memcg_events(memcg, PGREFILL));
 	seq_buf_printf(&s, "pgscan %lu\n",
 		       memcg_events(memcg, PGSCAN_KSWAPD) +
 		       memcg_events(memcg, PGSCAN_DIRECT));
 	seq_buf_printf(&s, "pgsteal %lu\n",
 		       memcg_events(memcg, PGSTEAL_KSWAPD) +
 		       memcg_events(memcg, PGSTEAL_DIRECT));
-	seq_buf_printf(&s, "pgactivate %lu\n", memcg_events(memcg, PGACTIVATE));
-	seq_buf_printf(&s, "pgdeactivate %lu\n", memcg_events(memcg, PGDEACTIVATE));
-	seq_buf_printf(&s, "pglazyfree %lu\n", memcg_events(memcg, PGLAZYFREE));
-	seq_buf_printf(&s, "pglazyfreed %lu\n", memcg_events(memcg, PGLAZYFREED));
+	seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGACTIVATE),
+		       memcg_events(memcg, PGACTIVATE));
+	seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGDEACTIVATE),
+		       memcg_events(memcg, PGDEACTIVATE));
+	seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREE),
+		       memcg_events(memcg, PGLAZYFREE));
+	seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREED),
+		       memcg_events(memcg, PGLAZYFREED));
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-	seq_buf_printf(&s, "thp_fault_alloc %lu\n",
+	seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_FAULT_ALLOC),
 		       memcg_events(memcg, THP_FAULT_ALLOC));
-	seq_buf_printf(&s, "thp_collapse_alloc %lu\n",
+	seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_COLLAPSE_ALLOC),
 		       memcg_events(memcg, THP_COLLAPSE_ALLOC));
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
@@ -3742,13 +3741,6 @@ static const unsigned int memcg1_events[] = {
 	PGMAJFAULT,
 };
 
-static const char *const memcg1_event_names[] = {
-	"pgpgin",
-	"pgpgout",
-	"pgfault",
-	"pgmajfault",
-};
-
 static int memcg_stat_show(struct seq_file *m, void *v)
 {
 	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
@@ -3757,7 +3749,6 @@ static int memcg_stat_show(struct seq_file *m, void *v)
 	unsigned int i;
 
 	BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats));
-	BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
 		if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
@@ -3768,11 +3759,11 @@ static int memcg_stat_show(struct seq_file *m, void *v)
 	}
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
-		seq_printf(m, "%s %lu\n", memcg1_event_names[i],
+		seq_printf(m, "%s %lu\n", vm_event_name(memcg1_events[i]),
 			   memcg_events_local(memcg, memcg1_events[i]));
 
 	for (i = 0; i < NR_LRU_LISTS; i++)
-		seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i],
+		seq_printf(m, "%s %lu\n", lru_list_name(i),
 			   memcg_page_state_local(memcg, NR_LRU_BASE + i) *
 			   PAGE_SIZE);
 
@@ -3797,11 +3788,12 @@ static int memcg_stat_show(struct seq_file *m, void *v)
 	}
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
-		seq_printf(m, "total_%s %llu\n", memcg1_event_names[i],
+		seq_printf(m, "total_%s %llu\n",
+			   vm_event_name(memcg1_events[i]),
 			   (u64)memcg_events(memcg, memcg1_events[i]));
 
 	for (i = 0; i < NR_LRU_LISTS; i++)
-		seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i],
+		seq_printf(m, "total_%s %llu\n", lru_list_name(i),
 			   (u64)memcg_page_state(memcg, NR_LRU_BASE + i) *
 			   PAGE_SIZE);
 
diff --git a/mm/memory.c b/mm/memory.c
index 513c3ecc76ee..606da187d1de 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -672,7 +672,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 
 	if (pmd_devmap(pmd))
 		return NULL;
-	if (is_zero_pfn(pfn))
+	if (is_huge_zero_pmd(pmd))
 		return NULL;
 	if (unlikely(pfn > highest_memmap_pfn))
 		return NULL;
@@ -4197,19 +4197,11 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 	smp_wmb(); /* See comment in __pte_alloc */
 
 	ptl = pud_lock(mm, pud);
-#ifndef __ARCH_HAS_4LEVEL_HACK
 	if (!pud_present(*pud)) {
 		mm_inc_nr_pmds(mm);
 		pud_populate(mm, pud, new);
 	} else	/* Another has populated it */
 		pmd_free(mm, new);
-#else
-	if (!pgd_present(*pud)) {
-		mm_inc_nr_pmds(mm);
-		pgd_populate(mm, pud, new);
-	} else /* Another has populated it */
-		pmd_free(mm, new);
-#endif /* __ARCH_HAS_4LEVEL_HACK */
 	spin_unlock(ptl);
 	return 0;
 }
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 8afa188f6e20..f0ab6d4ceb4c 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -904,6 +904,18 @@ static void flush_memcg_workqueue(struct kmem_cache *s)
 	 * previous workitems on workqueue are processed.
 	 */
 	flush_workqueue(memcg_kmem_cache_wq);
+
+	/*
+	 * If we're racing with children kmem_cache deactivation, it might
+	 * take another rcu grace period to complete their destruction.
+	 * At this moment the corresponding percpu_ref_kill() call should be
+	 * done, but it might take another rcu grace period to complete
+	 * switching to the atomic mode.
+	 * Please, note that we check without grabbing the slab_mutex. It's safe
+	 * because at this moment the children list can't grow.
+	 */
+	if (!list_empty(&s->memcg_params.children))
+		rcu_barrier();
 }
 #else
 static inline int shutdown_memcg_caches(struct kmem_cache *s)
diff --git a/mm/vmstat.c b/mm/vmstat.c
index a8222041bd44..78d53378db99 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1084,7 +1084,8 @@ int fragmentation_index(struct zone *zone, unsigned int order)
 }
 #endif
 
-#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || \
+    defined(CONFIG_NUMA) || defined(CONFIG_MEMCG)
 #ifdef CONFIG_ZONE_DMA
 #define TEXT_FOR_DMA(xx) xx "_dma",
 #else
@@ -1134,7 +1135,7 @@ const char * const vmstat_text[] = {
 	"numa_other",
 #endif
 
-	/* Node-based counters */
+	/* enum node_stat_item counters */
 	"nr_inactive_anon",
 	"nr_active_anon",
 	"nr_inactive_file",
@@ -1172,7 +1173,7 @@ const char * const vmstat_text[] = {
 	"nr_dirty_threshold",
 	"nr_dirty_background_threshold",
 
-#ifdef CONFIG_VM_EVENT_COUNTERS
+#if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
 	/* enum vm_event_item counters */
 	"pgpgin",
 	"pgpgout",
@@ -1291,9 +1292,9 @@ const char * const vmstat_text[] = {
 	"swap_ra",
 	"swap_ra_hit",
 #endif
-#endif /* CONFIG_VM_EVENTS_COUNTERS */
+#endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
 };
-#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
+#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */
 
 #if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
      defined(CONFIG_PROC_FS)
@@ -1564,10 +1565,8 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
 	if (is_zone_first_populated(pgdat, zone)) {
 		seq_printf(m, "\n  per-node stats");
 		for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
-			seq_printf(m, "\n      %-12s %lu",
-				vmstat_text[i + NR_VM_ZONE_STAT_ITEMS +
-				NR_VM_NUMA_STAT_ITEMS],
-				node_page_state(pgdat, i));
+			seq_printf(m, "\n      %-12s %lu", node_stat_name(i),
+				   node_page_state(pgdat, i));
 		}
 	}
 	seq_printf(m,
@@ -1600,14 +1599,13 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
 	}
 
 	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
-		seq_printf(m, "\n      %-12s %lu", vmstat_text[i],
-				zone_page_state(zone, i));
+		seq_printf(m, "\n      %-12s %lu", zone_stat_name(i),
+			   zone_page_state(zone, i));
 
 #ifdef CONFIG_NUMA
 	for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
-		seq_printf(m, "\n      %-12s %lu",
-				vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
-				zone_numa_state_snapshot(zone, i));
+		seq_printf(m, "\n      %-12s %lu", numa_stat_name(i),
+			   zone_numa_state_snapshot(zone, i));
 #endif
 
 	seq_printf(m, "\n  pagesets");
@@ -1658,31 +1656,23 @@ static const struct seq_operations zoneinfo_op = {
 	.show	= zoneinfo_show,
 };
 
-enum writeback_stat_item {
-	NR_DIRTY_THRESHOLD,
-	NR_DIRTY_BG_THRESHOLD,
-	NR_VM_WRITEBACK_STAT_ITEMS,
-};
+#define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \
+			 NR_VM_NUMA_STAT_ITEMS + \
+			 NR_VM_NODE_STAT_ITEMS + \
+			 NR_VM_WRITEBACK_STAT_ITEMS + \
+			 (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \
+			  NR_VM_EVENT_ITEMS : 0))
 
 static void *vmstat_start(struct seq_file *m, loff_t *pos)
 {
 	unsigned long *v;
-	int i, stat_items_size;
+	int i;
 
-	if (*pos >= ARRAY_SIZE(vmstat_text))
+	if (*pos >= NR_VMSTAT_ITEMS)
 		return NULL;
-	stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
-			  NR_VM_NUMA_STAT_ITEMS * sizeof(unsigned long) +
-			  NR_VM_NODE_STAT_ITEMS * sizeof(unsigned long) +
-			  NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
-
-#ifdef CONFIG_VM_EVENT_COUNTERS
-	stat_items_size += sizeof(struct vm_event_state);
-#endif
 
-	BUILD_BUG_ON(stat_items_size !=
-		     ARRAY_SIZE(vmstat_text) * sizeof(unsigned long));
-	v = kmalloc(stat_items_size, GFP_KERNEL);
+	BUILD_BUG_ON(ARRAY_SIZE(vmstat_text) < NR_VMSTAT_ITEMS);
+	v = kmalloc_array(NR_VMSTAT_ITEMS, sizeof(unsigned long), GFP_KERNEL);
 	m->private = v;
 	if (!v)
 		return ERR_PTR(-ENOMEM);
@@ -1715,7 +1705,7 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos)
 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
 {
 	(*pos)++;
-	if (*pos >= ARRAY_SIZE(vmstat_text))
+	if (*pos >= NR_VMSTAT_ITEMS)
 		return NULL;
 	return (unsigned long *)m->private + *pos;
 }
@@ -1781,7 +1771,7 @@ int vmstat_refresh(struct ctl_table *table, int write,
 		val = atomic_long_read(&vm_zone_stat[i]);
 		if (val < 0) {
 			pr_warn("%s: %s %ld\n",
-				__func__, vmstat_text[i], val);
+				__func__, zone_stat_name(i), val);
 			err = -EINVAL;
 		}
 	}
@@ -1790,7 +1780,7 @@ int vmstat_refresh(struct ctl_table *table, int write,
 		val = atomic_long_read(&vm_numa_stat[i]);
 		if (val < 0) {
 			pr_warn("%s: %s %ld\n",
-				__func__, vmstat_text[i + NR_VM_ZONE_STAT_ITEMS], val);
+				__func__, numa_stat_name(i), val);
 			err = -EINVAL;
 		}
 	}