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-rw-r--r--include/linux/mmzone.h13
-rw-r--r--include/linux/vmstat.h22
2 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 6e6e62648a4d..3984c4eb41fd 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -284,6 +284,13 @@ struct zone {
unsigned long watermark[NR_WMARK];
/*
+ * When free pages are below this point, additional steps are taken
+ * when reading the number of free pages to avoid per-cpu counter
+ * drift allowing watermarks to be breached
+ */
+ unsigned long percpu_drift_mark;
+
+ /*
* We don't know if the memory that we're going to allocate will be freeable
* or/and it will be released eventually, so to avoid totally wasting several
* GB of ram we must reserve some of the lower zone memory (otherwise we risk
@@ -441,6 +448,12 @@ static inline int zone_is_oom_locked(const struct zone *zone)
return test_bit(ZONE_OOM_LOCKED, &zone->flags);
}
+#ifdef CONFIG_SMP
+unsigned long zone_nr_free_pages(struct zone *zone);
+#else
+#define zone_nr_free_pages(zone) zone_page_state(zone, NR_FREE_PAGES)
+#endif /* CONFIG_SMP */
+
/*
* The "priority" of VM scanning is how much of the queues we will scan in one
* go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 7f43ccdc1d38..eaaea37b3b75 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -170,6 +170,28 @@ static inline unsigned long zone_page_state(struct zone *zone,
return x;
}
+/*
+ * More accurate version that also considers the currently pending
+ * deltas. For that we need to loop over all cpus to find the current
+ * deltas. There is no synchronization so the result cannot be
+ * exactly accurate either.
+ */
+static inline unsigned long zone_page_state_snapshot(struct zone *zone,
+ enum zone_stat_item item)
+{
+ long x = atomic_long_read(&zone->vm_stat[item]);
+
+#ifdef CONFIG_SMP
+ int cpu;
+ for_each_online_cpu(cpu)
+ x += per_cpu_ptr(zone->pageset, cpu)->vm_stat_diff[item];
+
+ if (x < 0)
+ x = 0;
+#endif
+ return x;
+}
+
extern unsigned long global_reclaimable_pages(void);
extern unsigned long zone_reclaimable_pages(struct zone *zone);