1 files changed, 50 insertions, 26 deletions

diff --git a/mm/vmstat.c b/mm/vmstat.c
index c54fd2924f25..8640a185dfc6 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -460,7 +460,7 @@ static int fold_diff(int *diff)
  *
  * The function returns the number of global counters updated.
  */
-static int refresh_cpu_vm_stats(void)
+static int refresh_cpu_vm_stats(bool do_pagesets)
 {
 	struct zone *zone;
 	int i;
@@ -484,33 +484,35 @@ static int refresh_cpu_vm_stats(void)
 #endif
 			}
 		}
-		cond_resched();
 #ifdef CONFIG_NUMA
-		/*
-		 * Deal with draining the remote pageset of this
-		 * processor
-		 *
-		 * Check if there are pages remaining in this pageset
-		 * if not then there is nothing to expire.
-		 */
-		if (!__this_cpu_read(p->expire) ||
+		if (do_pagesets) {
+			cond_resched();
+			/*
+			 * Deal with draining the remote pageset of this
+			 * processor
+			 *
+			 * Check if there are pages remaining in this pageset
+			 * if not then there is nothing to expire.
+			 */
+			if (!__this_cpu_read(p->expire) ||
 			       !__this_cpu_read(p->pcp.count))
-			continue;
+				continue;
 
-		/*
-		 * We never drain zones local to this processor.
-		 */
-		if (zone_to_nid(zone) == numa_node_id()) {
-			__this_cpu_write(p->expire, 0);
-			continue;
-		}
+			/*
+			 * We never drain zones local to this processor.
+			 */
+			if (zone_to_nid(zone) == numa_node_id()) {
+				__this_cpu_write(p->expire, 0);
+				continue;
+			}
 
-		if (__this_cpu_dec_return(p->expire))
-			continue;
+			if (__this_cpu_dec_return(p->expire))
+				continue;
 
-		if (__this_cpu_read(p->pcp.count)) {
-			drain_zone_pages(zone, this_cpu_ptr(&p->pcp));
-			changes++;
+			if (__this_cpu_read(p->pcp.count)) {
+				drain_zone_pages(zone, this_cpu_ptr(&p->pcp));
+				changes++;
+			}
 		}
 #endif
 	}
@@ -736,6 +738,7 @@ const char * const vmstat_text[] = {
 	"nr_slab_unreclaimable",
 	"nr_page_table_pages",
 	"nr_kernel_stack",
+	"nr_overhead",
 	"nr_unstable",
 	"nr_bounce",
 	"nr_vmscan_write",
@@ -1091,6 +1094,8 @@ 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;
@@ -1348,7 +1353,9 @@ static int vmstat_show(struct seq_file *m, void *arg)
 	unsigned long *l = arg;
 	unsigned long off = l - (unsigned long *)m->private;
 
-	seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
+	seq_puts(m, vmstat_text[off]);
+	seq_put_decimal_ull(m, ' ', *l);
+	seq_putc(m, '\n');
 	return 0;
 }
 
@@ -1386,7 +1393,7 @@ static cpumask_var_t cpu_stat_off;
 
 static void vmstat_update(struct work_struct *w)
 {
-	if (refresh_cpu_vm_stats()) {
+	if (refresh_cpu_vm_stats(true)) {
 		/*
 		 * Counters were updated so we expect more updates
 		 * to occur in the future. Keep on running the
@@ -1418,6 +1425,23 @@ static void vmstat_update(struct work_struct *w)
 }
 
 /*
+ * 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;
+
+	do {
+		if (!cpumask_test_and_set_cpu(smp_processor_id(), cpu_stat_off))
+			cancel_delayed_work(this_cpu_ptr(&vmstat_work));
+
+	} while (refresh_cpu_vm_stats(false));
+}
+
+/*
  * Check if the diffs for a certain cpu indicate that
  * an update is needed.
  */
@@ -1449,7 +1473,7 @@ static bool need_update(int cpu)
  */
 static void vmstat_shepherd(struct work_struct *w);
 
-static DECLARE_DELAYED_WORK(shepherd, vmstat_shepherd);
+static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd);
 
 static void vmstat_shepherd(struct work_struct *w)
 {