Linux-libre 4.7.1-gnupck-4.7.1-gnu

1 files changed, 86 insertions, 79 deletions

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 5e4300482..cb2a67bb4 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -570,49 +570,18 @@ void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
 
 #ifdef CONFIG_NUMA
 /*
- * zonelist = the list of zones passed to the allocator
- * z 	    = the zone from which the allocation occurred.
- *
- * Must be called with interrupts disabled.
- *
- * When __GFP_OTHER_NODE is set assume the node of the preferred
- * zone is the local node. This is useful for daemons who allocate
- * memory on behalf of other processes.
- */
-void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
-{
-	if (z->zone_pgdat == preferred_zone->zone_pgdat) {
-		__inc_zone_state(z, NUMA_HIT);
-	} else {
-		__inc_zone_state(z, NUMA_MISS);
-		__inc_zone_state(preferred_zone, NUMA_FOREIGN);
-	}
-	if (z->node == ((flags & __GFP_OTHER_NODE) ?
-			preferred_zone->node : numa_node_id()))
-		__inc_zone_state(z, NUMA_LOCAL);
-	else
-		__inc_zone_state(z, NUMA_OTHER);
-}
-
-/*
  * Determine the per node value of a stat item.
  */
 unsigned long node_page_state(int node, enum zone_stat_item item)
 {
 	struct zone *zones = NODE_DATA(node)->node_zones;
+	int i;
+	unsigned long count = 0;
 
-	return
-#ifdef CONFIG_ZONE_DMA
-		zone_page_state(&zones[ZONE_DMA], item) +
-#endif
-#ifdef CONFIG_ZONE_DMA32
-		zone_page_state(&zones[ZONE_DMA32], item) +
-#endif
-#ifdef CONFIG_HIGHMEM
-		zone_page_state(&zones[ZONE_HIGHMEM], item) +
-#endif
-		zone_page_state(&zones[ZONE_NORMAL], item) +
-		zone_page_state(&zones[ZONE_MOVABLE], item);
+	for (i = 0; i < MAX_NR_ZONES; i++)
+		count += zone_page_state(zones + i, item);
+
+	return count;
 }
 
 #endif
@@ -1010,6 +979,9 @@ static void pagetypeinfo_showblockcount_print(struct seq_file *m,
 		if (!memmap_valid_within(pfn, page, zone))
 			continue;
 
+		if (page_zone(page) != zone)
+			continue;
+
 		mtype = get_pageblock_migratetype(page);
 
 		if (mtype < MIGRATE_TYPES)
@@ -1069,13 +1041,17 @@ static void pagetypeinfo_showmixedcount_print(struct seq_file *m,
 		block_end_pfn = min(block_end_pfn, end_pfn);
 
 		page = pfn_to_page(pfn);
-		pageblock_mt = get_pfnblock_migratetype(page, pfn);
+		pageblock_mt = get_pageblock_migratetype(page);
 
 		for (; pfn < block_end_pfn; pfn++) {
 			if (!pfn_valid_within(pfn))
 				continue;
 
 			page = pfn_to_page(pfn);
+
+			if (page_zone(page) != zone)
+				continue;
+
 			if (PageBuddy(page)) {
 				pfn += (1UL << page_order(page)) - 1;
 				continue;
@@ -1085,6 +1061,8 @@ static void pagetypeinfo_showmixedcount_print(struct seq_file *m,
 				continue;
 
 			page_ext = lookup_page_ext(page);
+			if (unlikely(!page_ext))
+				continue;
 
 			if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
 				continue;
@@ -1376,7 +1354,66 @@ static const struct file_operations proc_vmstat_file_operations = {
 static struct workqueue_struct *vmstat_wq;
 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
 int sysctl_stat_interval __read_mostly = HZ;
-static cpumask_var_t cpu_stat_off;
+
+#ifdef CONFIG_PROC_FS
+static void refresh_vm_stats(struct work_struct *work)
+{
+	refresh_cpu_vm_stats(true);
+}
+
+int vmstat_refresh(struct ctl_table *table, int write,
+		   void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	long val;
+	int err;
+	int i;
+
+	/*
+	 * The regular update, every sysctl_stat_interval, may come later
+	 * than expected: leaving a significant amount in per_cpu buckets.
+	 * This is particularly misleading when checking a quantity of HUGE
+	 * pages, immediately after running a test.  /proc/sys/vm/stat_refresh,
+	 * which can equally be echo'ed to or cat'ted from (by root),
+	 * can be used to update the stats just before reading them.
+	 *
+	 * Oh, and since global_page_state() etc. are so careful to hide
+	 * transiently negative values, report an error here if any of
+	 * the stats is negative, so we know to go looking for imbalance.
+	 */
+	err = schedule_on_each_cpu(refresh_vm_stats);
+	if (err)
+		return err;
+	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
+		val = atomic_long_read(&vm_stat[i]);
+		if (val < 0) {
+			switch (i) {
+			case NR_ALLOC_BATCH:
+			case NR_PAGES_SCANNED:
+				/*
+				 * These are often seen to go negative in
+				 * recent kernels, but not to go permanently
+				 * negative.  Whilst it would be nicer not to
+				 * have exceptions, rooting them out would be
+				 * another task, of rather low priority.
+				 */
+				break;
+			default:
+				pr_warn("%s: %s %ld\n",
+					__func__, vmstat_text[i], val);
+				err = -EINVAL;
+				break;
+			}
+		}
+	}
+	if (err)
+		return err;
+	if (write)
+		*ppos += *lenp;
+	else
+		*lenp = 0;
+	return 0;
+}
+#endif /* CONFIG_PROC_FS */
 
 static void vmstat_update(struct work_struct *w)
 {
@@ -1385,24 +1422,10 @@ static void vmstat_update(struct work_struct *w)
 		 * Counters were updated so we expect more updates
 		 * to occur in the future. Keep on running the
 		 * update worker thread.
-		 * If we were marked on cpu_stat_off clear the flag
-		 * so that vmstat_shepherd doesn't schedule us again.
 		 */
-		if (!cpumask_test_and_clear_cpu(smp_processor_id(),
-						cpu_stat_off)) {
-			queue_delayed_work_on(smp_processor_id(), vmstat_wq,
+		queue_delayed_work_on(smp_processor_id(), vmstat_wq,
 				this_cpu_ptr(&vmstat_work),
 				round_jiffies_relative(sysctl_stat_interval));
-		}
-	} else {
-		/*
-		 * We did not update any counters so the app may be in
-		 * a mode where it does not cause counter updates.
-		 * We may be uselessly running vmstat_update.
-		 * Defer the checking for differentials to the
-		 * shepherd thread on a different processor.
-		 */
-		cpumask_set_cpu(smp_processor_id(), cpu_stat_off);
 	}
 }
 
@@ -1434,16 +1457,17 @@ static bool need_update(int cpu)
 	return false;
 }
 
+/*
+ * Switch off vmstat processing and then fold all the remaining differentials
+ * until the diffs stay at zero. The function is used by NOHZ and can only be
+ * invoked when tick processing is not active.
+ */
 void quiet_vmstat(void)
 {
 	if (system_state != SYSTEM_RUNNING)
 		return;
 
-	/*
-	 * If we are already in hands of the shepherd then there
-	 * is nothing for us to do here.
-	 */
-	if (cpumask_test_and_set_cpu(smp_processor_id(), cpu_stat_off))
+	if (!delayed_work_pending(this_cpu_ptr(&vmstat_work)))
 		return;
 
 	if (!need_update(smp_processor_id()))
@@ -1458,7 +1482,6 @@ void quiet_vmstat(void)
 	refresh_cpu_vm_stats(false);
 }
 
-
 /*
  * Shepherd worker thread that checks the
  * differentials of processors that have their worker
@@ -1475,20 +1498,11 @@ static void vmstat_shepherd(struct work_struct *w)
 
 	get_online_cpus();
 	/* Check processors whose vmstat worker threads have been disabled */
-	for_each_cpu(cpu, cpu_stat_off) {
+	for_each_online_cpu(cpu) {
 		struct delayed_work *dw = &per_cpu(vmstat_work, cpu);
 
-		if (need_update(cpu)) {
-			if (cpumask_test_and_clear_cpu(cpu, cpu_stat_off))
-				queue_delayed_work_on(cpu, vmstat_wq, dw, 0);
-		} else {
-			/*
-			 * Cancel the work if quiet_vmstat has put this
-			 * cpu on cpu_stat_off because the work item might
-			 * be still scheduled
-			 */
-			cancel_delayed_work(dw);
-		}
+		if (!delayed_work_pending(dw) && need_update(cpu))
+			queue_delayed_work_on(cpu, vmstat_wq, dw, 0);
 	}
 	put_online_cpus();
 
@@ -1504,10 +1518,6 @@ static void __init start_shepherd_timer(void)
 		INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu),
 			vmstat_update);
 
-	if (!alloc_cpumask_var(&cpu_stat_off, GFP_KERNEL))
-		BUG();
-	cpumask_copy(cpu_stat_off, cpu_online_mask);
-
 	vmstat_wq = alloc_workqueue("vmstat", WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
 	schedule_delayed_work(&shepherd,
 		round_jiffies_relative(sysctl_stat_interval));
@@ -1542,16 +1552,13 @@ static int vmstat_cpuup_callback(struct notifier_block *nfb,
 	case CPU_ONLINE_FROZEN:
 		refresh_zone_stat_thresholds();
 		node_set_state(cpu_to_node(cpu), N_CPU);
-		cpumask_set_cpu(cpu, cpu_stat_off);
 		break;
 	case CPU_DOWN_PREPARE:
 	case CPU_DOWN_PREPARE_FROZEN:
 		cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
-		cpumask_clear_cpu(cpu, cpu_stat_off);
 		break;
 	case CPU_DOWN_FAILED:
 	case CPU_DOWN_FAILED_FROZEN:
-		cpumask_set_cpu(cpu, cpu_stat_off);
 		break;
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN: