v4.19.13 snapshot.
diff --git a/mm/vmstat.c b/mm/vmstat.c
new file mode 100644
index 0000000..7878da7
--- /dev/null
+++ b/mm/vmstat.c
@@ -0,0 +1,2141 @@
+/*
+ * linux/mm/vmstat.c
+ *
+ * Manages VM statistics
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * zoned VM statistics
+ * Copyright (C) 2006 Silicon Graphics, Inc.,
+ * Christoph Lameter <christoph@lameter.com>
+ * Copyright (C) 2008-2014 Christoph Lameter
+ */
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/vmstat.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/sched.h>
+#include <linux/math64.h>
+#include <linux/writeback.h>
+#include <linux/compaction.h>
+#include <linux/mm_inline.h>
+#include <linux/page_ext.h>
+#include <linux/page_owner.h>
+
+#include "internal.h"
+
+#define NUMA_STATS_THRESHOLD (U16_MAX - 2)
+
+#ifdef CONFIG_NUMA
+int sysctl_vm_numa_stat = ENABLE_NUMA_STAT;
+
+/* zero numa counters within a zone */
+static void zero_zone_numa_counters(struct zone *zone)
+{
+ int item, cpu;
+
+ for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++) {
+ atomic_long_set(&zone->vm_numa_stat[item], 0);
+ for_each_online_cpu(cpu)
+ per_cpu_ptr(zone->pageset, cpu)->vm_numa_stat_diff[item]
+ = 0;
+ }
+}
+
+/* zero numa counters of all the populated zones */
+static void zero_zones_numa_counters(void)
+{
+ struct zone *zone;
+
+ for_each_populated_zone(zone)
+ zero_zone_numa_counters(zone);
+}
+
+/* zero global numa counters */
+static void zero_global_numa_counters(void)
+{
+ int item;
+
+ for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++)
+ atomic_long_set(&vm_numa_stat[item], 0);
+}
+
+static void invalid_numa_statistics(void)
+{
+ zero_zones_numa_counters();
+ zero_global_numa_counters();
+}
+
+static DEFINE_MUTEX(vm_numa_stat_lock);
+
+int sysctl_vm_numa_stat_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ int ret, oldval;
+
+ mutex_lock(&vm_numa_stat_lock);
+ if (write)
+ oldval = sysctl_vm_numa_stat;
+ ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (ret || !write)
+ goto out;
+
+ if (oldval == sysctl_vm_numa_stat)
+ goto out;
+ else if (sysctl_vm_numa_stat == ENABLE_NUMA_STAT) {
+ static_branch_enable(&vm_numa_stat_key);
+ pr_info("enable numa statistics\n");
+ } else {
+ static_branch_disable(&vm_numa_stat_key);
+ invalid_numa_statistics();
+ pr_info("disable numa statistics, and clear numa counters\n");
+ }
+
+out:
+ mutex_unlock(&vm_numa_stat_lock);
+ return ret;
+}
+#endif
+
+#ifdef CONFIG_VM_EVENT_COUNTERS
+DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
+EXPORT_PER_CPU_SYMBOL(vm_event_states);
+
+static void sum_vm_events(unsigned long *ret)
+{
+ int cpu;
+ int i;
+
+ memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
+
+ for_each_online_cpu(cpu) {
+ struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
+
+ for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
+ ret[i] += this->event[i];
+ }
+}
+
+/*
+ * Accumulate the vm event counters across all CPUs.
+ * The result is unavoidably approximate - it can change
+ * during and after execution of this function.
+*/
+void all_vm_events(unsigned long *ret)
+{
+ get_online_cpus();
+ sum_vm_events(ret);
+ put_online_cpus();
+}
+EXPORT_SYMBOL_GPL(all_vm_events);
+
+/*
+ * Fold the foreign cpu events into our own.
+ *
+ * This is adding to the events on one processor
+ * but keeps the global counts constant.
+ */
+void vm_events_fold_cpu(int cpu)
+{
+ struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
+ int i;
+
+ for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
+ count_vm_events(i, fold_state->event[i]);
+ fold_state->event[i] = 0;
+ }
+}
+
+#endif /* CONFIG_VM_EVENT_COUNTERS */
+
+/*
+ * Manage combined zone based / global counters
+ *
+ * vm_stat contains the global counters
+ */
+atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
+atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS] __cacheline_aligned_in_smp;
+atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp;
+EXPORT_SYMBOL(vm_zone_stat);
+EXPORT_SYMBOL(vm_numa_stat);
+EXPORT_SYMBOL(vm_node_stat);
+
+#ifdef CONFIG_SMP
+
+int calculate_pressure_threshold(struct zone *zone)
+{
+ int threshold;
+ int watermark_distance;
+
+ /*
+ * As vmstats are not up to date, there is drift between the estimated
+ * and real values. For high thresholds and a high number of CPUs, it
+ * is possible for the min watermark to be breached while the estimated
+ * value looks fine. The pressure threshold is a reduced value such
+ * that even the maximum amount of drift will not accidentally breach
+ * the min watermark
+ */
+ watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
+ threshold = max(1, (int)(watermark_distance / num_online_cpus()));
+
+ /*
+ * Maximum threshold is 125
+ */
+ threshold = min(125, threshold);
+
+ return threshold;
+}
+
+int calculate_normal_threshold(struct zone *zone)
+{
+ int threshold;
+ int mem; /* memory in 128 MB units */
+
+ /*
+ * The threshold scales with the number of processors and the amount
+ * of memory per zone. More memory means that we can defer updates for
+ * longer, more processors could lead to more contention.
+ * fls() is used to have a cheap way of logarithmic scaling.
+ *
+ * Some sample thresholds:
+ *
+ * Threshold Processors (fls) Zonesize fls(mem+1)
+ * ------------------------------------------------------------------
+ * 8 1 1 0.9-1 GB 4
+ * 16 2 2 0.9-1 GB 4
+ * 20 2 2 1-2 GB 5
+ * 24 2 2 2-4 GB 6
+ * 28 2 2 4-8 GB 7
+ * 32 2 2 8-16 GB 8
+ * 4 2 2 <128M 1
+ * 30 4 3 2-4 GB 5
+ * 48 4 3 8-16 GB 8
+ * 32 8 4 1-2 GB 4
+ * 32 8 4 0.9-1GB 4
+ * 10 16 5 <128M 1
+ * 40 16 5 900M 4
+ * 70 64 7 2-4 GB 5
+ * 84 64 7 4-8 GB 6
+ * 108 512 9 4-8 GB 6
+ * 125 1024 10 8-16 GB 8
+ * 125 1024 10 16-32 GB 9
+ */
+
+ mem = zone->managed_pages >> (27 - PAGE_SHIFT);
+
+ threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
+
+ /*
+ * Maximum threshold is 125
+ */
+ threshold = min(125, threshold);
+
+ return threshold;
+}
+
+/*
+ * Refresh the thresholds for each zone.
+ */
+void refresh_zone_stat_thresholds(void)
+{
+ struct pglist_data *pgdat;
+ struct zone *zone;
+ int cpu;
+ int threshold;
+
+ /* Zero current pgdat thresholds */
+ for_each_online_pgdat(pgdat) {
+ for_each_online_cpu(cpu) {
+ per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold = 0;
+ }
+ }
+
+ for_each_populated_zone(zone) {
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ unsigned long max_drift, tolerate_drift;
+
+ threshold = calculate_normal_threshold(zone);
+
+ for_each_online_cpu(cpu) {
+ int pgdat_threshold;
+
+ per_cpu_ptr(zone->pageset, cpu)->stat_threshold
+ = threshold;
+
+ /* Base nodestat threshold on the largest populated zone. */
+ pgdat_threshold = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold;
+ per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold
+ = max(threshold, pgdat_threshold);
+ }
+
+ /*
+ * Only set percpu_drift_mark if there is a danger that
+ * NR_FREE_PAGES reports the low watermark is ok when in fact
+ * the min watermark could be breached by an allocation
+ */
+ tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
+ max_drift = num_online_cpus() * threshold;
+ if (max_drift > tolerate_drift)
+ zone->percpu_drift_mark = high_wmark_pages(zone) +
+ max_drift;
+ }
+}
+
+void set_pgdat_percpu_threshold(pg_data_t *pgdat,
+ int (*calculate_pressure)(struct zone *))
+{
+ struct zone *zone;
+ int cpu;
+ int threshold;
+ int i;
+
+ for (i = 0; i < pgdat->nr_zones; i++) {
+ zone = &pgdat->node_zones[i];
+ if (!zone->percpu_drift_mark)
+ continue;
+
+ threshold = (*calculate_pressure)(zone);
+ for_each_online_cpu(cpu)
+ per_cpu_ptr(zone->pageset, cpu)->stat_threshold
+ = threshold;
+ }
+}
+
+/*
+ * For use when we know that interrupts are disabled,
+ * or when we know that preemption is disabled and that
+ * particular counter cannot be updated from interrupt context.
+ */
+void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
+ long delta)
+{
+ struct per_cpu_pageset __percpu *pcp = zone->pageset;
+ s8 __percpu *p = pcp->vm_stat_diff + item;
+ long x;
+ long t;
+
+ x = delta + __this_cpu_read(*p);
+
+ t = __this_cpu_read(pcp->stat_threshold);
+
+ if (unlikely(x > t || x < -t)) {
+ zone_page_state_add(x, zone, item);
+ x = 0;
+ }
+ __this_cpu_write(*p, x);
+}
+EXPORT_SYMBOL(__mod_zone_page_state);
+
+void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
+ long delta)
+{
+ struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+ s8 __percpu *p = pcp->vm_node_stat_diff + item;
+ long x;
+ long t;
+
+ x = delta + __this_cpu_read(*p);
+
+ t = __this_cpu_read(pcp->stat_threshold);
+
+ if (unlikely(x > t || x < -t)) {
+ node_page_state_add(x, pgdat, item);
+ x = 0;
+ }
+ __this_cpu_write(*p, x);
+}
+EXPORT_SYMBOL(__mod_node_page_state);
+
+/*
+ * Optimized increment and decrement functions.
+ *
+ * These are only for a single page and therefore can take a struct page *
+ * argument instead of struct zone *. This allows the inclusion of the code
+ * generated for page_zone(page) into the optimized functions.
+ *
+ * No overflow check is necessary and therefore the differential can be
+ * incremented or decremented in place which may allow the compilers to
+ * generate better code.
+ * The increment or decrement is known and therefore one boundary check can
+ * be omitted.
+ *
+ * NOTE: These functions are very performance sensitive. Change only
+ * with care.
+ *
+ * Some processors have inc/dec instructions that are atomic vs an interrupt.
+ * However, the code must first determine the differential location in a zone
+ * based on the processor number and then inc/dec the counter. There is no
+ * guarantee without disabling preemption that the processor will not change
+ * in between and therefore the atomicity vs. interrupt cannot be exploited
+ * in a useful way here.
+ */
+void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
+{
+ struct per_cpu_pageset __percpu *pcp = zone->pageset;
+ s8 __percpu *p = pcp->vm_stat_diff + item;
+ s8 v, t;
+
+ v = __this_cpu_inc_return(*p);
+ t = __this_cpu_read(pcp->stat_threshold);
+ if (unlikely(v > t)) {
+ s8 overstep = t >> 1;
+
+ zone_page_state_add(v + overstep, zone, item);
+ __this_cpu_write(*p, -overstep);
+ }
+}
+
+void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+ s8 __percpu *p = pcp->vm_node_stat_diff + item;
+ s8 v, t;
+
+ v = __this_cpu_inc_return(*p);
+ t = __this_cpu_read(pcp->stat_threshold);
+ if (unlikely(v > t)) {
+ s8 overstep = t >> 1;
+
+ node_page_state_add(v + overstep, pgdat, item);
+ __this_cpu_write(*p, -overstep);
+ }
+}
+
+void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ __inc_zone_state(page_zone(page), item);
+}
+EXPORT_SYMBOL(__inc_zone_page_state);
+
+void __inc_node_page_state(struct page *page, enum node_stat_item item)
+{
+ __inc_node_state(page_pgdat(page), item);
+}
+EXPORT_SYMBOL(__inc_node_page_state);
+
+void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
+{
+ struct per_cpu_pageset __percpu *pcp = zone->pageset;
+ s8 __percpu *p = pcp->vm_stat_diff + item;
+ s8 v, t;
+
+ v = __this_cpu_dec_return(*p);
+ t = __this_cpu_read(pcp->stat_threshold);
+ if (unlikely(v < - t)) {
+ s8 overstep = t >> 1;
+
+ zone_page_state_add(v - overstep, zone, item);
+ __this_cpu_write(*p, overstep);
+ }
+}
+
+void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+ s8 __percpu *p = pcp->vm_node_stat_diff + item;
+ s8 v, t;
+
+ v = __this_cpu_dec_return(*p);
+ t = __this_cpu_read(pcp->stat_threshold);
+ if (unlikely(v < - t)) {
+ s8 overstep = t >> 1;
+
+ node_page_state_add(v - overstep, pgdat, item);
+ __this_cpu_write(*p, overstep);
+ }
+}
+
+void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ __dec_zone_state(page_zone(page), item);
+}
+EXPORT_SYMBOL(__dec_zone_page_state);
+
+void __dec_node_page_state(struct page *page, enum node_stat_item item)
+{
+ __dec_node_state(page_pgdat(page), item);
+}
+EXPORT_SYMBOL(__dec_node_page_state);
+
+#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
+/*
+ * If we have cmpxchg_local support then we do not need to incur the overhead
+ * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
+ *
+ * mod_state() modifies the zone counter state through atomic per cpu
+ * operations.
+ *
+ * Overstep mode specifies how overstep should handled:
+ * 0 No overstepping
+ * 1 Overstepping half of threshold
+ * -1 Overstepping minus half of threshold
+*/
+static inline void mod_zone_state(struct zone *zone,
+ enum zone_stat_item item, long delta, int overstep_mode)
+{
+ struct per_cpu_pageset __percpu *pcp = zone->pageset;
+ s8 __percpu *p = pcp->vm_stat_diff + item;
+ long o, n, t, z;
+
+ do {
+ z = 0; /* overflow to zone counters */
+
+ /*
+ * The fetching of the stat_threshold is racy. We may apply
+ * a counter threshold to the wrong the cpu if we get
+ * rescheduled while executing here. However, the next
+ * counter update will apply the threshold again and
+ * therefore bring the counter under the threshold again.
+ *
+ * Most of the time the thresholds are the same anyways
+ * for all cpus in a zone.
+ */
+ t = this_cpu_read(pcp->stat_threshold);
+
+ o = this_cpu_read(*p);
+ n = delta + o;
+
+ if (n > t || n < -t) {
+ int os = overstep_mode * (t >> 1) ;
+
+ /* Overflow must be added to zone counters */
+ z = n + os;
+ n = -os;
+ }
+ } while (this_cpu_cmpxchg(*p, o, n) != o);
+
+ if (z)
+ zone_page_state_add(z, zone, item);
+}
+
+void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
+ long delta)
+{
+ mod_zone_state(zone, item, delta, 0);
+}
+EXPORT_SYMBOL(mod_zone_page_state);
+
+void inc_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ mod_zone_state(page_zone(page), item, 1, 1);
+}
+EXPORT_SYMBOL(inc_zone_page_state);
+
+void dec_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ mod_zone_state(page_zone(page), item, -1, -1);
+}
+EXPORT_SYMBOL(dec_zone_page_state);
+
+static inline void mod_node_state(struct pglist_data *pgdat,
+ enum node_stat_item item, int delta, int overstep_mode)
+{
+ struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+ s8 __percpu *p = pcp->vm_node_stat_diff + item;
+ long o, n, t, z;
+
+ do {
+ z = 0; /* overflow to node counters */
+
+ /*
+ * The fetching of the stat_threshold is racy. We may apply
+ * a counter threshold to the wrong the cpu if we get
+ * rescheduled while executing here. However, the next
+ * counter update will apply the threshold again and
+ * therefore bring the counter under the threshold again.
+ *
+ * Most of the time the thresholds are the same anyways
+ * for all cpus in a node.
+ */
+ t = this_cpu_read(pcp->stat_threshold);
+
+ o = this_cpu_read(*p);
+ n = delta + o;
+
+ if (n > t || n < -t) {
+ int os = overstep_mode * (t >> 1) ;
+
+ /* Overflow must be added to node counters */
+ z = n + os;
+ n = -os;
+ }
+ } while (this_cpu_cmpxchg(*p, o, n) != o);
+
+ if (z)
+ node_page_state_add(z, pgdat, item);
+}
+
+void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
+ long delta)
+{
+ mod_node_state(pgdat, item, delta, 0);
+}
+EXPORT_SYMBOL(mod_node_page_state);
+
+void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ mod_node_state(pgdat, item, 1, 1);
+}
+
+void inc_node_page_state(struct page *page, enum node_stat_item item)
+{
+ mod_node_state(page_pgdat(page), item, 1, 1);
+}
+EXPORT_SYMBOL(inc_node_page_state);
+
+void dec_node_page_state(struct page *page, enum node_stat_item item)
+{
+ mod_node_state(page_pgdat(page), item, -1, -1);
+}
+EXPORT_SYMBOL(dec_node_page_state);
+#else
+/*
+ * Use interrupt disable to serialize counter updates
+ */
+void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
+ long delta)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __mod_zone_page_state(zone, item, delta);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(mod_zone_page_state);
+
+void inc_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ unsigned long flags;
+ struct zone *zone;
+
+ zone = page_zone(page);
+ local_irq_save(flags);
+ __inc_zone_state(zone, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(inc_zone_page_state);
+
+void dec_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __dec_zone_page_state(page, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(dec_zone_page_state);
+
+void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __inc_node_state(pgdat, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(inc_node_state);
+
+void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
+ long delta)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __mod_node_page_state(pgdat, item, delta);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(mod_node_page_state);
+
+void inc_node_page_state(struct page *page, enum node_stat_item item)
+{
+ unsigned long flags;
+ struct pglist_data *pgdat;
+
+ pgdat = page_pgdat(page);
+ local_irq_save(flags);
+ __inc_node_state(pgdat, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(inc_node_page_state);
+
+void dec_node_page_state(struct page *page, enum node_stat_item item)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __dec_node_page_state(page, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(dec_node_page_state);
+#endif
+
+/*
+ * Fold a differential into the global counters.
+ * Returns the number of counters updated.
+ */
+#ifdef CONFIG_NUMA
+static int fold_diff(int *zone_diff, int *numa_diff, int *node_diff)
+{
+ int i;
+ int changes = 0;
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ if (zone_diff[i]) {
+ atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
+ changes++;
+ }
+
+ for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
+ if (numa_diff[i]) {
+ atomic_long_add(numa_diff[i], &vm_numa_stat[i]);
+ changes++;
+ }
+
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+ if (node_diff[i]) {
+ atomic_long_add(node_diff[i], &vm_node_stat[i]);
+ changes++;
+ }
+ return changes;
+}
+#else
+static int fold_diff(int *zone_diff, int *node_diff)
+{
+ int i;
+ int changes = 0;
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ if (zone_diff[i]) {
+ atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
+ changes++;
+ }
+
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+ if (node_diff[i]) {
+ atomic_long_add(node_diff[i], &vm_node_stat[i]);
+ changes++;
+ }
+ return changes;
+}
+#endif /* CONFIG_NUMA */
+
+/*
+ * Update the zone counters for the current cpu.
+ *
+ * Note that refresh_cpu_vm_stats strives to only access
+ * node local memory. The per cpu pagesets on remote zones are placed
+ * in the memory local to the processor using that pageset. So the
+ * loop over all zones will access a series of cachelines local to
+ * the processor.
+ *
+ * The call to zone_page_state_add updates the cachelines with the
+ * statistics in the remote zone struct as well as the global cachelines
+ * with the global counters. These could cause remote node cache line
+ * bouncing and will have to be only done when necessary.
+ *
+ * The function returns the number of global counters updated.
+ */
+static int refresh_cpu_vm_stats(bool do_pagesets)
+{
+ struct pglist_data *pgdat;
+ struct zone *zone;
+ int i;
+ int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+#ifdef CONFIG_NUMA
+ int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, };
+#endif
+ int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
+ int changes = 0;
+
+ for_each_populated_zone(zone) {
+ struct per_cpu_pageset __percpu *p = zone->pageset;
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
+ int v;
+
+ v = this_cpu_xchg(p->vm_stat_diff[i], 0);
+ if (v) {
+
+ atomic_long_add(v, &zone->vm_stat[i]);
+ global_zone_diff[i] += v;
+#ifdef CONFIG_NUMA
+ /* 3 seconds idle till flush */
+ __this_cpu_write(p->expire, 3);
+#endif
+ }
+ }
+#ifdef CONFIG_NUMA
+ for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) {
+ int v;
+
+ v = this_cpu_xchg(p->vm_numa_stat_diff[i], 0);
+ if (v) {
+
+ atomic_long_add(v, &zone->vm_numa_stat[i]);
+ global_numa_diff[i] += v;
+ __this_cpu_write(p->expire, 3);
+ }
+ }
+
+ 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;
+
+ /*
+ * 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_read(p->pcp.count)) {
+ drain_zone_pages(zone, this_cpu_ptr(&p->pcp));
+ changes++;
+ }
+ }
+#endif
+ }
+
+ for_each_online_pgdat(pgdat) {
+ struct per_cpu_nodestat __percpu *p = pgdat->per_cpu_nodestats;
+
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
+ int v;
+
+ v = this_cpu_xchg(p->vm_node_stat_diff[i], 0);
+ if (v) {
+ atomic_long_add(v, &pgdat->vm_stat[i]);
+ global_node_diff[i] += v;
+ }
+ }
+ }
+
+#ifdef CONFIG_NUMA
+ changes += fold_diff(global_zone_diff, global_numa_diff,
+ global_node_diff);
+#else
+ changes += fold_diff(global_zone_diff, global_node_diff);
+#endif
+ return changes;
+}
+
+/*
+ * Fold the data for an offline cpu into the global array.
+ * There cannot be any access by the offline cpu and therefore
+ * synchronization is simplified.
+ */
+void cpu_vm_stats_fold(int cpu)
+{
+ struct pglist_data *pgdat;
+ struct zone *zone;
+ int i;
+ int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+#ifdef CONFIG_NUMA
+ int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, };
+#endif
+ int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
+
+ for_each_populated_zone(zone) {
+ struct per_cpu_pageset *p;
+
+ p = per_cpu_ptr(zone->pageset, cpu);
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ if (p->vm_stat_diff[i]) {
+ int v;
+
+ v = p->vm_stat_diff[i];
+ p->vm_stat_diff[i] = 0;
+ atomic_long_add(v, &zone->vm_stat[i]);
+ global_zone_diff[i] += v;
+ }
+
+#ifdef CONFIG_NUMA
+ for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
+ if (p->vm_numa_stat_diff[i]) {
+ int v;
+
+ v = p->vm_numa_stat_diff[i];
+ p->vm_numa_stat_diff[i] = 0;
+ atomic_long_add(v, &zone->vm_numa_stat[i]);
+ global_numa_diff[i] += v;
+ }
+#endif
+ }
+
+ for_each_online_pgdat(pgdat) {
+ struct per_cpu_nodestat *p;
+
+ p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu);
+
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+ if (p->vm_node_stat_diff[i]) {
+ int v;
+
+ v = p->vm_node_stat_diff[i];
+ p->vm_node_stat_diff[i] = 0;
+ atomic_long_add(v, &pgdat->vm_stat[i]);
+ global_node_diff[i] += v;
+ }
+ }
+
+#ifdef CONFIG_NUMA
+ fold_diff(global_zone_diff, global_numa_diff, global_node_diff);
+#else
+ fold_diff(global_zone_diff, global_node_diff);
+#endif
+}
+
+/*
+ * this is only called if !populated_zone(zone), which implies no other users of
+ * pset->vm_stat_diff[] exsist.
+ */
+void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
+{
+ int i;
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ if (pset->vm_stat_diff[i]) {
+ int v = pset->vm_stat_diff[i];
+ pset->vm_stat_diff[i] = 0;
+ atomic_long_add(v, &zone->vm_stat[i]);
+ atomic_long_add(v, &vm_zone_stat[i]);
+ }
+
+#ifdef CONFIG_NUMA
+ for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
+ if (pset->vm_numa_stat_diff[i]) {
+ int v = pset->vm_numa_stat_diff[i];
+
+ pset->vm_numa_stat_diff[i] = 0;
+ atomic_long_add(v, &zone->vm_numa_stat[i]);
+ atomic_long_add(v, &vm_numa_stat[i]);
+ }
+#endif
+}
+#endif
+
+#ifdef CONFIG_NUMA
+void __inc_numa_state(struct zone *zone,
+ enum numa_stat_item item)
+{
+ struct per_cpu_pageset __percpu *pcp = zone->pageset;
+ u16 __percpu *p = pcp->vm_numa_stat_diff + item;
+ u16 v;
+
+ v = __this_cpu_inc_return(*p);
+
+ if (unlikely(v > NUMA_STATS_THRESHOLD)) {
+ zone_numa_state_add(v, zone, item);
+ __this_cpu_write(*p, 0);
+ }
+}
+
+/*
+ * Determine the per node value of a stat item. This function
+ * is called frequently in a NUMA machine, so try to be as
+ * frugal as possible.
+ */
+unsigned long sum_zone_node_page_state(int node,
+ enum zone_stat_item item)
+{
+ struct zone *zones = NODE_DATA(node)->node_zones;
+ int i;
+ unsigned long count = 0;
+
+ for (i = 0; i < MAX_NR_ZONES; i++)
+ count += zone_page_state(zones + i, item);
+
+ return count;
+}
+
+/*
+ * Determine the per node value of a numa stat item. To avoid deviation,
+ * the per cpu stat number in vm_numa_stat_diff[] is also included.
+ */
+unsigned long sum_zone_numa_state(int node,
+ enum numa_stat_item item)
+{
+ struct zone *zones = NODE_DATA(node)->node_zones;
+ int i;
+ unsigned long count = 0;
+
+ for (i = 0; i < MAX_NR_ZONES; i++)
+ count += zone_numa_state_snapshot(zones + i, item);
+
+ return count;
+}
+
+/*
+ * Determine the per node value of a stat item.
+ */
+unsigned long node_page_state(struct pglist_data *pgdat,
+ enum node_stat_item item)
+{
+ long x = atomic_long_read(&pgdat->vm_stat[item]);
+#ifdef CONFIG_SMP
+ if (x < 0)
+ x = 0;
+#endif
+ return x;
+}
+#endif
+
+#ifdef CONFIG_COMPACTION
+
+struct contig_page_info {
+ unsigned long free_pages;
+ unsigned long free_blocks_total;
+ unsigned long free_blocks_suitable;
+};
+
+/*
+ * Calculate the number of free pages in a zone, how many contiguous
+ * pages are free and how many are large enough to satisfy an allocation of
+ * the target size. Note that this function makes no attempt to estimate
+ * how many suitable free blocks there *might* be if MOVABLE pages were
+ * migrated. Calculating that is possible, but expensive and can be
+ * figured out from userspace
+ */
+static void fill_contig_page_info(struct zone *zone,
+ unsigned int suitable_order,
+ struct contig_page_info *info)
+{
+ unsigned int order;
+
+ info->free_pages = 0;
+ info->free_blocks_total = 0;
+ info->free_blocks_suitable = 0;
+
+ for (order = 0; order < MAX_ORDER; order++) {
+ unsigned long blocks;
+
+ /* Count number of free blocks */
+ blocks = zone->free_area[order].nr_free;
+ info->free_blocks_total += blocks;
+
+ /* Count free base pages */
+ info->free_pages += blocks << order;
+
+ /* Count the suitable free blocks */
+ if (order >= suitable_order)
+ info->free_blocks_suitable += blocks <<
+ (order - suitable_order);
+ }
+}
+
+/*
+ * A fragmentation index only makes sense if an allocation of a requested
+ * size would fail. If that is true, the fragmentation index indicates
+ * whether external fragmentation or a lack of memory was the problem.
+ * The value can be used to determine if page reclaim or compaction
+ * should be used
+ */
+static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
+{
+ unsigned long requested = 1UL << order;
+
+ if (WARN_ON_ONCE(order >= MAX_ORDER))
+ return 0;
+
+ if (!info->free_blocks_total)
+ return 0;
+
+ /* Fragmentation index only makes sense when a request would fail */
+ if (info->free_blocks_suitable)
+ return -1000;
+
+ /*
+ * Index is between 0 and 1 so return within 3 decimal places
+ *
+ * 0 => allocation would fail due to lack of memory
+ * 1 => allocation would fail due to fragmentation
+ */
+ return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
+}
+
+/* Same as __fragmentation index but allocs contig_page_info on stack */
+int fragmentation_index(struct zone *zone, unsigned int order)
+{
+ struct contig_page_info info;
+
+ fill_contig_page_info(zone, order, &info);
+ return __fragmentation_index(order, &info);
+}
+#endif
+
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
+#ifdef CONFIG_ZONE_DMA
+#define TEXT_FOR_DMA(xx) xx "_dma",
+#else
+#define TEXT_FOR_DMA(xx)
+#endif
+
+#ifdef CONFIG_ZONE_DMA32
+#define TEXT_FOR_DMA32(xx) xx "_dma32",
+#else
+#define TEXT_FOR_DMA32(xx)
+#endif
+
+#ifdef CONFIG_HIGHMEM
+#define TEXT_FOR_HIGHMEM(xx) xx "_high",
+#else
+#define TEXT_FOR_HIGHMEM(xx)
+#endif
+
+#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
+ TEXT_FOR_HIGHMEM(xx) xx "_movable",
+
+const char * const vmstat_text[] = {
+ /* enum zone_stat_item countes */
+ "nr_free_pages",
+ "nr_zone_inactive_anon",
+ "nr_zone_active_anon",
+ "nr_zone_inactive_file",
+ "nr_zone_active_file",
+ "nr_zone_unevictable",
+ "nr_zone_write_pending",
+ "nr_mlock",
+ "nr_page_table_pages",
+ "nr_kernel_stack",
+ "nr_bounce",
+#if IS_ENABLED(CONFIG_ZSMALLOC)
+ "nr_zspages",
+#endif
+ "nr_free_cma",
+
+ /* enum numa_stat_item counters */
+#ifdef CONFIG_NUMA
+ "numa_hit",
+ "numa_miss",
+ "numa_foreign",
+ "numa_interleave",
+ "numa_local",
+ "numa_other",
+#endif
+
+ /* Node-based counters */
+ "nr_inactive_anon",
+ "nr_active_anon",
+ "nr_inactive_file",
+ "nr_active_file",
+ "nr_unevictable",
+ "nr_slab_reclaimable",
+ "nr_slab_unreclaimable",
+ "nr_isolated_anon",
+ "nr_isolated_file",
+ "workingset_refault",
+ "workingset_activate",
+ "workingset_nodereclaim",
+ "nr_anon_pages",
+ "nr_mapped",
+ "nr_file_pages",
+ "nr_dirty",
+ "nr_writeback",
+ "nr_writeback_temp",
+ "nr_shmem",
+ "nr_shmem_hugepages",
+ "nr_shmem_pmdmapped",
+ "nr_anon_transparent_hugepages",
+ "nr_unstable",
+ "nr_vmscan_write",
+ "nr_vmscan_immediate_reclaim",
+ "nr_dirtied",
+ "nr_written",
+ "", /* nr_indirectly_reclaimable */
+
+ /* enum writeback_stat_item counters */
+ "nr_dirty_threshold",
+ "nr_dirty_background_threshold",
+
+#ifdef CONFIG_VM_EVENT_COUNTERS
+ /* enum vm_event_item counters */
+ "pgpgin",
+ "pgpgout",
+ "pswpin",
+ "pswpout",
+
+ TEXTS_FOR_ZONES("pgalloc")
+ TEXTS_FOR_ZONES("allocstall")
+ TEXTS_FOR_ZONES("pgskip")
+
+ "pgfree",
+ "pgactivate",
+ "pgdeactivate",
+ "pglazyfree",
+
+ "pgfault",
+ "pgmajfault",
+ "pglazyfreed",
+
+ "pgrefill",
+ "pgsteal_kswapd",
+ "pgsteal_direct",
+ "pgscan_kswapd",
+ "pgscan_direct",
+ "pgscan_direct_throttle",
+
+#ifdef CONFIG_NUMA
+ "zone_reclaim_failed",
+#endif
+ "pginodesteal",
+ "slabs_scanned",
+ "kswapd_inodesteal",
+ "kswapd_low_wmark_hit_quickly",
+ "kswapd_high_wmark_hit_quickly",
+ "pageoutrun",
+
+ "pgrotated",
+
+ "drop_pagecache",
+ "drop_slab",
+ "oom_kill",
+
+#ifdef CONFIG_NUMA_BALANCING
+ "numa_pte_updates",
+ "numa_huge_pte_updates",
+ "numa_hint_faults",
+ "numa_hint_faults_local",
+ "numa_pages_migrated",
+#endif
+#ifdef CONFIG_MIGRATION
+ "pgmigrate_success",
+ "pgmigrate_fail",
+#endif
+#ifdef CONFIG_COMPACTION
+ "compact_migrate_scanned",
+ "compact_free_scanned",
+ "compact_isolated",
+ "compact_stall",
+ "compact_fail",
+ "compact_success",
+ "compact_daemon_wake",
+ "compact_daemon_migrate_scanned",
+ "compact_daemon_free_scanned",
+#endif
+
+#ifdef CONFIG_HUGETLB_PAGE
+ "htlb_buddy_alloc_success",
+ "htlb_buddy_alloc_fail",
+#endif
+ "unevictable_pgs_culled",
+ "unevictable_pgs_scanned",
+ "unevictable_pgs_rescued",
+ "unevictable_pgs_mlocked",
+ "unevictable_pgs_munlocked",
+ "unevictable_pgs_cleared",
+ "unevictable_pgs_stranded",
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ "thp_fault_alloc",
+ "thp_fault_fallback",
+ "thp_collapse_alloc",
+ "thp_collapse_alloc_failed",
+ "thp_file_alloc",
+ "thp_file_mapped",
+ "thp_split_page",
+ "thp_split_page_failed",
+ "thp_deferred_split_page",
+ "thp_split_pmd",
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+ "thp_split_pud",
+#endif
+ "thp_zero_page_alloc",
+ "thp_zero_page_alloc_failed",
+ "thp_swpout",
+ "thp_swpout_fallback",
+#endif
+#ifdef CONFIG_MEMORY_BALLOON
+ "balloon_inflate",
+ "balloon_deflate",
+#ifdef CONFIG_BALLOON_COMPACTION
+ "balloon_migrate",
+#endif
+#endif /* CONFIG_MEMORY_BALLOON */
+#ifdef CONFIG_DEBUG_TLBFLUSH
+#ifdef CONFIG_SMP
+ "nr_tlb_remote_flush",
+ "nr_tlb_remote_flush_received",
+#else
+ "", /* nr_tlb_remote_flush */
+ "", /* nr_tlb_remote_flush_received */
+#endif /* CONFIG_SMP */
+ "nr_tlb_local_flush_all",
+ "nr_tlb_local_flush_one",
+#endif /* CONFIG_DEBUG_TLBFLUSH */
+
+#ifdef CONFIG_DEBUG_VM_VMACACHE
+ "vmacache_find_calls",
+ "vmacache_find_hits",
+#endif
+#ifdef CONFIG_SWAP
+ "swap_ra",
+ "swap_ra_hit",
+#endif
+#endif /* CONFIG_VM_EVENTS_COUNTERS */
+};
+#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
+
+#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
+ defined(CONFIG_PROC_FS)
+static void *frag_start(struct seq_file *m, loff_t *pos)
+{
+ pg_data_t *pgdat;
+ loff_t node = *pos;
+
+ for (pgdat = first_online_pgdat();
+ pgdat && node;
+ pgdat = next_online_pgdat(pgdat))
+ --node;
+
+ return pgdat;
+}
+
+static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ (*pos)++;
+ return next_online_pgdat(pgdat);
+}
+
+static void frag_stop(struct seq_file *m, void *arg)
+{
+}
+
+/*
+ * Walk zones in a node and print using a callback.
+ * If @assert_populated is true, only use callback for zones that are populated.
+ */
+static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
+ bool assert_populated, bool nolock,
+ void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
+{
+ struct zone *zone;
+ struct zone *node_zones = pgdat->node_zones;
+ unsigned long flags;
+
+ for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
+ if (assert_populated && !populated_zone(zone))
+ continue;
+
+ if (!nolock)
+ spin_lock_irqsave(&zone->lock, flags);
+ print(m, pgdat, zone);
+ if (!nolock)
+ spin_unlock_irqrestore(&zone->lock, flags);
+ }
+}
+#endif
+
+#ifdef CONFIG_PROC_FS
+static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
+ struct zone *zone)
+{
+ int order;
+
+ seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
+ for (order = 0; order < MAX_ORDER; ++order)
+ seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
+ seq_putc(m, '\n');
+}
+
+/*
+ * This walks the free areas for each zone.
+ */
+static int frag_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+ walk_zones_in_node(m, pgdat, true, false, frag_show_print);
+ return 0;
+}
+
+static void pagetypeinfo_showfree_print(struct seq_file *m,
+ pg_data_t *pgdat, struct zone *zone)
+{
+ int order, mtype;
+
+ for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
+ seq_printf(m, "Node %4d, zone %8s, type %12s ",
+ pgdat->node_id,
+ zone->name,
+ migratetype_names[mtype]);
+ for (order = 0; order < MAX_ORDER; ++order) {
+ unsigned long freecount = 0;
+ struct free_area *area;
+ struct list_head *curr;
+
+ area = &(zone->free_area[order]);
+
+ list_for_each(curr, &area->free_list[mtype])
+ freecount++;
+ seq_printf(m, "%6lu ", freecount);
+ }
+ seq_putc(m, '\n');
+ }
+}
+
+/* Print out the free pages at each order for each migatetype */
+static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
+{
+ int order;
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ /* Print header */
+ seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
+ for (order = 0; order < MAX_ORDER; ++order)
+ seq_printf(m, "%6d ", order);
+ seq_putc(m, '\n');
+
+ walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print);
+
+ return 0;
+}
+
+static void pagetypeinfo_showblockcount_print(struct seq_file *m,
+ pg_data_t *pgdat, struct zone *zone)
+{
+ int mtype;
+ unsigned long pfn;
+ unsigned long start_pfn = zone->zone_start_pfn;
+ unsigned long end_pfn = zone_end_pfn(zone);
+ unsigned long count[MIGRATE_TYPES] = { 0, };
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
+ struct page *page;
+
+ page = pfn_to_online_page(pfn);
+ if (!page)
+ continue;
+
+ /* Watch for unexpected holes punched in the memmap */
+ if (!memmap_valid_within(pfn, page, zone))
+ continue;
+
+ if (page_zone(page) != zone)
+ continue;
+
+ mtype = get_pageblock_migratetype(page);
+
+ if (mtype < MIGRATE_TYPES)
+ count[mtype]++;
+ }
+
+ /* Print counts */
+ seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
+ for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
+ seq_printf(m, "%12lu ", count[mtype]);
+ seq_putc(m, '\n');
+}
+
+/* Print out the number of pageblocks for each migratetype */
+static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
+{
+ int mtype;
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ seq_printf(m, "\n%-23s", "Number of blocks type ");
+ for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
+ seq_printf(m, "%12s ", migratetype_names[mtype]);
+ seq_putc(m, '\n');
+ walk_zones_in_node(m, pgdat, true, false,
+ pagetypeinfo_showblockcount_print);
+
+ return 0;
+}
+
+/*
+ * Print out the number of pageblocks for each migratetype that contain pages
+ * of other types. This gives an indication of how well fallbacks are being
+ * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
+ * to determine what is going on
+ */
+static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
+{
+#ifdef CONFIG_PAGE_OWNER
+ int mtype;
+
+ if (!static_branch_unlikely(&page_owner_inited))
+ return;
+
+ drain_all_pages(NULL);
+
+ seq_printf(m, "\n%-23s", "Number of mixed blocks ");
+ for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
+ seq_printf(m, "%12s ", migratetype_names[mtype]);
+ seq_putc(m, '\n');
+
+ walk_zones_in_node(m, pgdat, true, true,
+ pagetypeinfo_showmixedcount_print);
+#endif /* CONFIG_PAGE_OWNER */
+}
+
+/*
+ * This prints out statistics in relation to grouping pages by mobility.
+ * It is expensive to collect so do not constantly read the file.
+ */
+static int pagetypeinfo_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ /* check memoryless node */
+ if (!node_state(pgdat->node_id, N_MEMORY))
+ return 0;
+
+ seq_printf(m, "Page block order: %d\n", pageblock_order);
+ seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
+ seq_putc(m, '\n');
+ pagetypeinfo_showfree(m, pgdat);
+ pagetypeinfo_showblockcount(m, pgdat);
+ pagetypeinfo_showmixedcount(m, pgdat);
+
+ return 0;
+}
+
+static const struct seq_operations fragmentation_op = {
+ .start = frag_start,
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = frag_show,
+};
+
+static const struct seq_operations pagetypeinfo_op = {
+ .start = frag_start,
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = pagetypeinfo_show,
+};
+
+static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone)
+{
+ int zid;
+
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ struct zone *compare = &pgdat->node_zones[zid];
+
+ if (populated_zone(compare))
+ return zone == compare;
+ }
+
+ return false;
+}
+
+static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
+ struct zone *zone)
+{
+ int i;
+ seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
+ 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 pages free %lu"
+ "\n min %lu"
+ "\n low %lu"
+ "\n high %lu"
+ "\n spanned %lu"
+ "\n present %lu"
+ "\n managed %lu",
+ zone_page_state(zone, NR_FREE_PAGES),
+ min_wmark_pages(zone),
+ low_wmark_pages(zone),
+ high_wmark_pages(zone),
+ zone->spanned_pages,
+ zone->present_pages,
+ zone->managed_pages);
+
+ seq_printf(m,
+ "\n protection: (%ld",
+ zone->lowmem_reserve[0]);
+ for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
+ seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
+ seq_putc(m, ')');
+
+ /* If unpopulated, no other information is useful */
+ if (!populated_zone(zone)) {
+ seq_putc(m, '\n');
+ return;
+ }
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ seq_printf(m, "\n %-12s %lu", vmstat_text[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));
+#endif
+
+ seq_printf(m, "\n pagesets");
+ for_each_online_cpu(i) {
+ struct per_cpu_pageset *pageset;
+
+ pageset = per_cpu_ptr(zone->pageset, i);
+ seq_printf(m,
+ "\n cpu: %i"
+ "\n count: %i"
+ "\n high: %i"
+ "\n batch: %i",
+ i,
+ pageset->pcp.count,
+ pageset->pcp.high,
+ pageset->pcp.batch);
+#ifdef CONFIG_SMP
+ seq_printf(m, "\n vm stats threshold: %d",
+ pageset->stat_threshold);
+#endif
+ }
+ seq_printf(m,
+ "\n node_unreclaimable: %u"
+ "\n start_pfn: %lu",
+ pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES,
+ zone->zone_start_pfn);
+ seq_putc(m, '\n');
+}
+
+/*
+ * Output information about zones in @pgdat. All zones are printed regardless
+ * of whether they are populated or not: lowmem_reserve_ratio operates on the
+ * set of all zones and userspace would not be aware of such zones if they are
+ * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio).
+ */
+static int zoneinfo_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+ walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print);
+ return 0;
+}
+
+static const struct seq_operations zoneinfo_op = {
+ .start = frag_start, /* iterate over all zones. The same as in
+ * fragmentation. */
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = zoneinfo_show,
+};
+
+enum writeback_stat_item {
+ NR_DIRTY_THRESHOLD,
+ NR_DIRTY_BG_THRESHOLD,
+ NR_VM_WRITEBACK_STAT_ITEMS,
+};
+
+static void *vmstat_start(struct seq_file *m, loff_t *pos)
+{
+ unsigned long *v;
+ int i, stat_items_size;
+
+ if (*pos >= ARRAY_SIZE(vmstat_text))
+ 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
+
+ v = kmalloc(stat_items_size, GFP_KERNEL);
+ m->private = v;
+ if (!v)
+ return ERR_PTR(-ENOMEM);
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ v[i] = global_zone_page_state(i);
+ v += NR_VM_ZONE_STAT_ITEMS;
+
+#ifdef CONFIG_NUMA
+ for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
+ v[i] = global_numa_state(i);
+ v += NR_VM_NUMA_STAT_ITEMS;
+#endif
+
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+ v[i] = global_node_page_state(i);
+ v += NR_VM_NODE_STAT_ITEMS;
+
+ global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
+ v + NR_DIRTY_THRESHOLD);
+ v += NR_VM_WRITEBACK_STAT_ITEMS;
+
+#ifdef CONFIG_VM_EVENT_COUNTERS
+ all_vm_events(v);
+ v[PGPGIN] /= 2; /* sectors -> kbytes */
+ v[PGPGOUT] /= 2;
+#endif
+ return (unsigned long *)m->private + *pos;
+}
+
+static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
+{
+ (*pos)++;
+ if (*pos >= ARRAY_SIZE(vmstat_text))
+ return NULL;
+ return (unsigned long *)m->private + *pos;
+}
+
+static int vmstat_show(struct seq_file *m, void *arg)
+{
+ unsigned long *l = arg;
+ unsigned long off = l - (unsigned long *)m->private;
+
+ /* Skip hidden vmstat items. */
+ if (*vmstat_text[off] == '\0')
+ return 0;
+
+ seq_puts(m, vmstat_text[off]);
+ seq_put_decimal_ull(m, " ", *l);
+ seq_putc(m, '\n');
+ return 0;
+}
+
+static void vmstat_stop(struct seq_file *m, void *arg)
+{
+ kfree(m->private);
+ m->private = NULL;
+}
+
+static const struct seq_operations vmstat_op = {
+ .start = vmstat_start,
+ .next = vmstat_next,
+ .stop = vmstat_stop,
+ .show = vmstat_show,
+};
+#endif /* CONFIG_PROC_FS */
+
+#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
+int sysctl_stat_interval __read_mostly = HZ;
+
+#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_zone_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_zone_stat[i]);
+ if (val < 0) {
+ pr_warn("%s: %s %ld\n",
+ __func__, vmstat_text[i], val);
+ err = -EINVAL;
+ }
+ }
+#ifdef CONFIG_NUMA
+ for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) {
+ 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);
+ err = -EINVAL;
+ }
+ }
+#endif
+ 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)
+{
+ if (refresh_cpu_vm_stats(true)) {
+ /*
+ * Counters were updated so we expect more updates
+ * to occur in the future. Keep on running the
+ * update worker thread.
+ */
+ queue_delayed_work_on(smp_processor_id(), mm_percpu_wq,
+ this_cpu_ptr(&vmstat_work),
+ round_jiffies_relative(sysctl_stat_interval));
+ }
+}
+
+/*
+ * 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.
+ */
+/*
+ * Check if the diffs for a certain cpu indicate that
+ * an update is needed.
+ */
+static bool need_update(int cpu)
+{
+ struct zone *zone;
+
+ for_each_populated_zone(zone) {
+ struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu);
+
+ BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1);
+#ifdef CONFIG_NUMA
+ BUILD_BUG_ON(sizeof(p->vm_numa_stat_diff[0]) != 2);
+#endif
+
+ /*
+ * The fast way of checking if there are any vmstat diffs.
+ * This works because the diffs are byte sized items.
+ */
+ if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS))
+ return true;
+#ifdef CONFIG_NUMA
+ if (memchr_inv(p->vm_numa_stat_diff, 0, NR_VM_NUMA_STAT_ITEMS))
+ return true;
+#endif
+ }
+ 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 (!delayed_work_pending(this_cpu_ptr(&vmstat_work)))
+ return;
+
+ if (!need_update(smp_processor_id()))
+ return;
+
+ /*
+ * Just refresh counters and do not care about the pending delayed
+ * vmstat_update. It doesn't fire that often to matter and canceling
+ * it would be too expensive from this path.
+ * vmstat_shepherd will take care about that for us.
+ */
+ refresh_cpu_vm_stats(false);
+}
+
+/*
+ * Shepherd worker thread that checks the
+ * differentials of processors that have their worker
+ * threads for vm statistics updates disabled because of
+ * inactivity.
+ */
+static void vmstat_shepherd(struct work_struct *w);
+
+static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd);
+
+static void vmstat_shepherd(struct work_struct *w)
+{
+ int cpu;
+
+ get_online_cpus();
+ /* Check processors whose vmstat worker threads have been disabled */
+ for_each_online_cpu(cpu) {
+ struct delayed_work *dw = &per_cpu(vmstat_work, cpu);
+
+ if (!delayed_work_pending(dw) && need_update(cpu))
+ queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0);
+ }
+ put_online_cpus();
+
+ schedule_delayed_work(&shepherd,
+ round_jiffies_relative(sysctl_stat_interval));
+}
+
+static void __init start_shepherd_timer(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu),
+ vmstat_update);
+
+ schedule_delayed_work(&shepherd,
+ round_jiffies_relative(sysctl_stat_interval));
+}
+
+static void __init init_cpu_node_state(void)
+{
+ int node;
+
+ for_each_online_node(node) {
+ if (cpumask_weight(cpumask_of_node(node)) > 0)
+ node_set_state(node, N_CPU);
+ }
+}
+
+static int vmstat_cpu_online(unsigned int cpu)
+{
+ refresh_zone_stat_thresholds();
+ node_set_state(cpu_to_node(cpu), N_CPU);
+ return 0;
+}
+
+static int vmstat_cpu_down_prep(unsigned int cpu)
+{
+ cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
+ return 0;
+}
+
+static int vmstat_cpu_dead(unsigned int cpu)
+{
+ const struct cpumask *node_cpus;
+ int node;
+
+ node = cpu_to_node(cpu);
+
+ refresh_zone_stat_thresholds();
+ node_cpus = cpumask_of_node(node);
+ if (cpumask_weight(node_cpus) > 0)
+ return 0;
+
+ node_clear_state(node, N_CPU);
+ return 0;
+}
+
+#endif
+
+struct workqueue_struct *mm_percpu_wq;
+
+void __init init_mm_internals(void)
+{
+ int ret __maybe_unused;
+
+ mm_percpu_wq = alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM, 0);
+
+#ifdef CONFIG_SMP
+ ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead",
+ NULL, vmstat_cpu_dead);
+ if (ret < 0)
+ pr_err("vmstat: failed to register 'dead' hotplug state\n");
+
+ ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "mm/vmstat:online",
+ vmstat_cpu_online,
+ vmstat_cpu_down_prep);
+ if (ret < 0)
+ pr_err("vmstat: failed to register 'online' hotplug state\n");
+
+ get_online_cpus();
+ init_cpu_node_state();
+ put_online_cpus();
+
+ start_shepherd_timer();
+#endif
+#ifdef CONFIG_PROC_FS
+ proc_create_seq("buddyinfo", 0444, NULL, &fragmentation_op);
+ proc_create_seq("pagetypeinfo", 0444, NULL, &pagetypeinfo_op);
+ proc_create_seq("vmstat", 0444, NULL, &vmstat_op);
+ proc_create_seq("zoneinfo", 0444, NULL, &zoneinfo_op);
+#endif
+}
+
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
+
+/*
+ * Return an index indicating how much of the available free memory is
+ * unusable for an allocation of the requested size.
+ */
+static int unusable_free_index(unsigned int order,
+ struct contig_page_info *info)
+{
+ /* No free memory is interpreted as all free memory is unusable */
+ if (info->free_pages == 0)
+ return 1000;
+
+ /*
+ * Index should be a value between 0 and 1. Return a value to 3
+ * decimal places.
+ *
+ * 0 => no fragmentation
+ * 1 => high fragmentation
+ */
+ return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
+
+}
+
+static void unusable_show_print(struct seq_file *m,
+ pg_data_t *pgdat, struct zone *zone)
+{
+ unsigned int order;
+ int index;
+ struct contig_page_info info;
+
+ seq_printf(m, "Node %d, zone %8s ",
+ pgdat->node_id,
+ zone->name);
+ for (order = 0; order < MAX_ORDER; ++order) {
+ fill_contig_page_info(zone, order, &info);
+ index = unusable_free_index(order, &info);
+ seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
+ }
+
+ seq_putc(m, '\n');
+}
+
+/*
+ * Display unusable free space index
+ *
+ * The unusable free space index measures how much of the available free
+ * memory cannot be used to satisfy an allocation of a given size and is a
+ * value between 0 and 1. The higher the value, the more of free memory is
+ * unusable and by implication, the worse the external fragmentation is. This
+ * can be expressed as a percentage by multiplying by 100.
+ */
+static int unusable_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ /* check memoryless node */
+ if (!node_state(pgdat->node_id, N_MEMORY))
+ return 0;
+
+ walk_zones_in_node(m, pgdat, true, false, unusable_show_print);
+
+ return 0;
+}
+
+static const struct seq_operations unusable_op = {
+ .start = frag_start,
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = unusable_show,
+};
+
+static int unusable_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &unusable_op);
+}
+
+static const struct file_operations unusable_file_ops = {
+ .open = unusable_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static void extfrag_show_print(struct seq_file *m,
+ pg_data_t *pgdat, struct zone *zone)
+{
+ unsigned int order;
+ int index;
+
+ /* Alloc on stack as interrupts are disabled for zone walk */
+ struct contig_page_info info;
+
+ seq_printf(m, "Node %d, zone %8s ",
+ pgdat->node_id,
+ zone->name);
+ for (order = 0; order < MAX_ORDER; ++order) {
+ fill_contig_page_info(zone, order, &info);
+ index = __fragmentation_index(order, &info);
+ seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
+ }
+
+ seq_putc(m, '\n');
+}
+
+/*
+ * Display fragmentation index for orders that allocations would fail for
+ */
+static int extfrag_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ walk_zones_in_node(m, pgdat, true, false, extfrag_show_print);
+
+ return 0;
+}
+
+static const struct seq_operations extfrag_op = {
+ .start = frag_start,
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = extfrag_show,
+};
+
+static int extfrag_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &extfrag_op);
+}
+
+static const struct file_operations extfrag_file_ops = {
+ .open = extfrag_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int __init extfrag_debug_init(void)
+{
+ struct dentry *extfrag_debug_root;
+
+ extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
+ if (!extfrag_debug_root)
+ return -ENOMEM;
+
+ if (!debugfs_create_file("unusable_index", 0444,
+ extfrag_debug_root, NULL, &unusable_file_ops))
+ goto fail;
+
+ if (!debugfs_create_file("extfrag_index", 0444,
+ extfrag_debug_root, NULL, &extfrag_file_ops))
+ goto fail;
+
+ return 0;
+fail:
+ debugfs_remove_recursive(extfrag_debug_root);
+ return -ENOMEM;
+}
+
+module_init(extfrag_debug_init);
+#endif