]> nv-tegra.nvidia Code Review - linux-2.6.git/blobdiff - mm/vmstat.c
config: tegra3: enable /dev mount with ACL
[linux-2.6.git] / mm / vmstat.c
index 38254297a4942c0bc0f1bcfa71e4c66dc24bc489..d52b13d28e8f4b25b827cd386693330655ff9174 100644 (file)
@@ -8,33 +8,32 @@
  *  Copyright (C) 2006 Silicon Graphics, Inc.,
  *             Christoph Lameter <christoph@lameter.com>
  */
-
+#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/vmstat.h>
 #include <linux/sched.h>
+#include <linux/math64.h>
+#include <linux/writeback.h>
+#include <linux/compaction.h>
 
 #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, cpumask_t *cpumask)
+static void sum_vm_events(unsigned long *ret)
 {
-       int cpu = 0;
+       int cpu;
        int i;
 
        memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
 
-       cpu = first_cpu(*cpumask);
-       while (cpu < NR_CPUS) {
+       for_each_online_cpu(cpu) {
                struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
 
-               cpu = next_cpu(cpu, *cpumask);
-
-               if (cpu < NR_CPUS)
-                       prefetch(&per_cpu(vm_event_states, cpu));
-
-
                for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
                        ret[i] += this->event[i];
        }
@@ -47,7 +46,9 @@ static void sum_vm_events(unsigned long *ret, cpumask_t *cpumask)
 */
 void all_vm_events(unsigned long *ret)
 {
-       sum_vm_events(ret, &cpu_online_map);
+       get_online_cpus();
+       sum_vm_events(ret);
+       put_online_cpus();
 }
 EXPORT_SYMBOL_GPL(all_vm_events);
 
@@ -82,7 +83,31 @@ EXPORT_SYMBOL(vm_stat);
 
 #ifdef CONFIG_SMP
 
-static int calculate_threshold(struct zone *zone)
+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 */
@@ -132,21 +157,51 @@ static int calculate_threshold(struct zone *zone)
 /*
  * Refresh the thresholds for each zone.
  */
-static void refresh_zone_stat_thresholds(void)
+void refresh_zone_stat_thresholds(void)
 {
        struct zone *zone;
        int cpu;
        int threshold;
 
-       for_each_zone(zone) {
-
-               if (!zone->present_pages)
-                       continue;
+       for_each_populated_zone(zone) {
+               unsigned long max_drift, tolerate_drift;
 
-               threshold = calculate_threshold(zone);
+               threshold = calculate_normal_threshold(zone);
 
                for_each_online_cpu(cpu)
-                       zone_pcp(zone, cpu)->stat_threshold = threshold;
+                       per_cpu_ptr(zone->pageset, cpu)->stat_threshold
+                                                       = 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_possible_cpu(cpu)
+                       per_cpu_ptr(zone->pageset, cpu)->stat_threshold
+                                                       = threshold;
        }
 }
 
@@ -156,34 +211,23 @@ static void refresh_zone_stat_thresholds(void)
 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
                                int delta)
 {
-       struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
-       s8 *p = pcp->vm_stat_diff + item;
+       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);
 
-       x = delta + *p;
+       t = __this_cpu_read(pcp->stat_threshold);
 
-       if (unlikely(x > pcp->stat_threshold || x < -pcp->stat_threshold)) {
+       if (unlikely(x > t || x < -t)) {
                zone_page_state_add(x, zone, item);
                x = 0;
        }
-       *p = x;
+       __this_cpu_write(*p, x);
 }
 EXPORT_SYMBOL(__mod_zone_page_state);
 
-/*
- * For an unknown interrupt state
- */
-void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
-                                       int 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);
-
 /*
  * Optimized increment and decrement functions.
  *
@@ -209,16 +253,17 @@ EXPORT_SYMBOL(mod_zone_page_state);
  */
 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
 {
-       struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
-       s8 *p = pcp->vm_stat_diff + item;
-
-       (*p)++;
+       struct per_cpu_pageset __percpu *pcp = zone->pageset;
+       s8 __percpu *p = pcp->vm_stat_diff + item;
+       s8 v, t;
 
-       if (unlikely(*p > pcp->stat_threshold)) {
-               int overstep = pcp->stat_threshold / 2;
+       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(*p + overstep, zone, item);
-               *p = -overstep;
+               zone_page_state_add(v + overstep, zone, item);
+               __this_cpu_write(*p, -overstep);
        }
 }
 
@@ -230,16 +275,17 @@ EXPORT_SYMBOL(__inc_zone_page_state);
 
 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
 {
-       struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
-       s8 *p = pcp->vm_stat_diff + item;
+       struct per_cpu_pageset __percpu *pcp = zone->pageset;
+       s8 __percpu *p = pcp->vm_stat_diff + item;
+       s8 v, t;
 
-       (*p)--;
+       v = __this_cpu_dec_return(*p);
+       t = __this_cpu_read(pcp->stat_threshold);
+       if (unlikely(v < - t)) {
+               s8 overstep = t >> 1;
 
-       if (unlikely(*p < - pcp->stat_threshold)) {
-               int overstep = pcp->stat_threshold / 2;
-
-               zone_page_state_add(*p - overstep, zone, item);
-               *p = overstep;
+               zone_page_state_add(v - overstep, zone, item);
+               __this_cpu_write(*p, overstep);
        }
 }
 
@@ -249,6 +295,95 @@ void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
 }
 EXPORT_SYMBOL(__dec_zone_page_state);
 
+#ifdef CONFIG_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_state(struct zone *zone,
+       enum zone_stat_item item, int 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,
+                                       int delta)
+{
+       mod_state(zone, item, delta, 0);
+}
+EXPORT_SYMBOL(mod_zone_page_state);
+
+void inc_zone_state(struct zone *zone, enum zone_stat_item item)
+{
+       mod_state(zone, item, 1, 1);
+}
+
+void inc_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+       mod_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_state(page_zone(page), item, -1, -1);
+}
+EXPORT_SYMBOL(dec_zone_page_state);
+#else
+/*
+ * Use interrupt disable to serialize counter updates
+ */
+void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
+                                       int 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_state(struct zone *zone, enum zone_stat_item item)
 {
        unsigned long flags;
@@ -279,10 +414,15 @@ void dec_zone_page_state(struct page *page, enum zone_stat_item item)
        local_irq_restore(flags);
 }
 EXPORT_SYMBOL(dec_zone_page_state);
+#endif
 
 /*
  * Update the zone counters for one cpu.
  *
+ * The cpu specified must be either the current cpu or a processor that
+ * is not online. If it is the current cpu then the execution thread must
+ * be pinned to 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
@@ -298,28 +438,30 @@ void refresh_cpu_vm_stats(int cpu)
 {
        struct zone *zone;
        int i;
-       unsigned long flags;
+       int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
 
-       for_each_zone(zone) {
+       for_each_populated_zone(zone) {
                struct per_cpu_pageset *p;
 
-               if (!populated_zone(zone))
-                       continue;
-
-               p = zone_pcp(zone, cpu);
+               p = per_cpu_ptr(zone->pageset, cpu);
 
                for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
                        if (p->vm_stat_diff[i]) {
+                               unsigned long flags;
+                               int v;
+
                                local_irq_save(flags);
-                               zone_page_state_add(p->vm_stat_diff[i],
-                                       zone, i);
+                               v = p->vm_stat_diff[i];
                                p->vm_stat_diff[i] = 0;
+                               local_irq_restore(flags);
+                               atomic_long_add(v, &zone->vm_stat[i]);
+                               global_diff[i] += v;
 #ifdef CONFIG_NUMA
                                /* 3 seconds idle till flush */
                                p->expire = 3;
 #endif
-                               local_irq_restore(flags);
                        }
+               cond_resched();
 #ifdef CONFIG_NUMA
                /*
                 * Deal with draining the remote pageset of this
@@ -328,7 +470,7 @@ void refresh_cpu_vm_stats(int cpu)
                 * Check if there are pages remaining in this pageset
                 * if not then there is nothing to expire.
                 */
-               if (!p->expire || (!p->pcp[0].count && !p->pcp[1].count))
+               if (!p->expire || !p->pcp.count)
                        continue;
 
                /*
@@ -343,31 +485,15 @@ void refresh_cpu_vm_stats(int cpu)
                if (p->expire)
                        continue;
 
-               if (p->pcp[0].count)
-                       drain_zone_pages(zone, p->pcp + 0);
-
-               if (p->pcp[1].count)
-                       drain_zone_pages(zone, p->pcp + 1);
+               if (p->pcp.count)
+                       drain_zone_pages(zone, &p->pcp);
 #endif
        }
-}
-
-static void __refresh_cpu_vm_stats(void *dummy)
-{
-       refresh_cpu_vm_stats(smp_processor_id());
-}
 
-/*
- * Consolidate all counters.
- *
- * Note that the result is less inaccurate but still inaccurate
- * if concurrent processes are allowed to run.
- */
-void refresh_vm_stats(void)
-{
-       on_each_cpu(__refresh_cpu_vm_stats, NULL, 0, 1);
+       for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+               if (global_diff[i])
+                       atomic_long_add(global_diff[i], &vm_stat[i]);
 }
-EXPORT_SYMBOL(refresh_vm_stats);
 
 #endif
 
@@ -377,26 +503,119 @@ EXPORT_SYMBOL(refresh_vm_stats);
  * 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 zonelist *zonelist, struct zone *z)
+void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
 {
-       if (z->zone_pgdat == zonelist->zones[0]->zone_pgdat) {
+       if (z->zone_pgdat == preferred_zone->zone_pgdat) {
                __inc_zone_state(z, NUMA_HIT);
        } else {
                __inc_zone_state(z, NUMA_MISS);
-               __inc_zone_state(zonelist->zones[0], NUMA_FOREIGN);
+               __inc_zone_state(preferred_zone, NUMA_FOREIGN);
        }
-       if (z->node == numa_node_id())
+       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);
 }
 #endif
 
-#ifdef CONFIG_PROC_FS
+#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 (!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_COMPACTION)
+#include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 
+static char * const migratetype_names[MIGRATE_TYPES] = {
+       "Unmovable",
+       "Reclaimable",
+       "Movable",
+       "Reserve",
+       "Isolate",
+};
+
 static void *frag_start(struct seq_file *m, loff_t *pos)
 {
        pg_data_t *pgdat;
@@ -421,38 +640,26 @@ static void frag_stop(struct seq_file *m, void *arg)
 {
 }
 
-/*
- * This walks the free areas for each zone.
- */
-static int frag_show(struct seq_file *m, void *arg)
+/* Walk all the zones in a node and print using a callback */
+static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
+               void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
 {
-       pg_data_t *pgdat = (pg_data_t *)arg;
        struct zone *zone;
        struct zone *node_zones = pgdat->node_zones;
        unsigned long flags;
-       int order;
 
        for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
                if (!populated_zone(zone))
                        continue;
 
                spin_lock_irqsave(&zone->lock, flags);
-               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);
+               print(m, pgdat, zone);
                spin_unlock_irqrestore(&zone->lock, flags);
-               seq_putc(m, '\n');
        }
-       return 0;
 }
+#endif
 
-const struct seq_operations fragmentation_op = {
-       .start  = frag_start,
-       .next   = frag_next,
-       .stop   = frag_stop,
-       .show   = frag_show,
-};
-
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
 #ifdef CONFIG_ZONE_DMA
 #define TEXT_FOR_DMA(xx) xx "_dma",
 #else
@@ -472,13 +679,17 @@ const struct seq_operations fragmentation_op = {
 #endif
 
 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
-                                       TEXT_FOR_HIGHMEM(xx)
+                                       TEXT_FOR_HIGHMEM(xx) xx "_movable",
 
-static const char * const vmstat_text[] = {
+const char * const vmstat_text[] = {
        /* Zoned VM counters */
        "nr_free_pages",
-       "nr_active",
-       "nr_inactive",
+       "nr_inactive_anon",
+       "nr_active_anon",
+       "nr_inactive_file",
+       "nr_active_file",
+       "nr_unevictable",
+       "nr_mlock",
        "nr_anon_pages",
        "nr_mapped",
        "nr_file_pages",
@@ -487,9 +698,16 @@ static const char * const vmstat_text[] = {
        "nr_slab_reclaimable",
        "nr_slab_unreclaimable",
        "nr_page_table_pages",
+       "nr_kernel_stack",
        "nr_unstable",
        "nr_bounce",
        "nr_vmscan_write",
+       "nr_writeback_temp",
+       "nr_isolated_anon",
+       "nr_isolated_file",
+       "nr_shmem",
+       "nr_dirtied",
+       "nr_written",
 
 #ifdef CONFIG_NUMA
        "numa_hit",
@@ -499,6 +717,9 @@ static const char * const vmstat_text[] = {
        "numa_local",
        "numa_other",
 #endif
+       "nr_anon_transparent_hugepages",
+       "nr_dirty_threshold",
+       "nr_dirty_background_threshold",
 
 #ifdef CONFIG_VM_EVENT_COUNTERS
        "pgpgin",
@@ -520,99 +741,300 @@ static const char * const vmstat_text[] = {
        TEXTS_FOR_ZONES("pgscan_kswapd")
        TEXTS_FOR_ZONES("pgscan_direct")
 
+#ifdef CONFIG_NUMA
+       "zone_reclaim_failed",
+#endif
        "pginodesteal",
        "slabs_scanned",
        "kswapd_steal",
        "kswapd_inodesteal",
+       "kswapd_low_wmark_hit_quickly",
+       "kswapd_high_wmark_hit_quickly",
+       "kswapd_skip_congestion_wait",
        "pageoutrun",
        "allocstall",
 
        "pgrotated",
+
+#ifdef CONFIG_COMPACTION
+       "compact_blocks_moved",
+       "compact_pages_moved",
+       "compact_pagemigrate_failed",
+       "compact_stall",
+       "compact_fail",
+       "compact_success",
+#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",
+       "unevictable_pgs_mlockfreed",
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       "thp_fault_alloc",
+       "thp_fault_fallback",
+       "thp_collapse_alloc",
+       "thp_collapse_alloc_failed",
+       "thp_split",
 #endif
+
+#endif /* CONFIG_VM_EVENTS_COUNTERS */
 };
+#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
+
+
+#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');
+}
 
 /*
- * Output information about zones in @pgdat.
+ * This walks the free areas for each zone.
  */
-static int zoneinfo_show(struct seq_file *m, void *arg)
+static int frag_show(struct seq_file *m, void *arg)
 {
-       pg_data_t *pgdat = arg;
-       struct zone *zone;
-       struct zone *node_zones = pgdat->node_zones;
-       unsigned long flags;
+       pg_data_t *pgdat = (pg_data_t *)arg;
+       walk_zones_in_node(m, pgdat, 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;
 
-       for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
-               int i;
+       /* 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');
 
-               if (!populated_zone(zone))
+       walk_zones_in_node(m, pgdat, 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 = start_pfn + zone->spanned_pages;
+       unsigned long count[MIGRATE_TYPES] = { 0, };
+
+       for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
+               struct page *page;
+
+               if (!pfn_valid(pfn))
                        continue;
 
-               spin_lock_irqsave(&zone->lock, flags);
-               seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
-               seq_printf(m,
-                          "\n  pages free     %lu"
-                          "\n        min      %lu"
-                          "\n        low      %lu"
-                          "\n        high     %lu"
-                          "\n        scanned  %lu (a: %lu i: %lu)"
-                          "\n        spanned  %lu"
-                          "\n        present  %lu",
-                          zone_page_state(zone, NR_FREE_PAGES),
-                          zone->pages_min,
-                          zone->pages_low,
-                          zone->pages_high,
-                          zone->pages_scanned,
-                          zone->nr_scan_active, zone->nr_scan_inactive,
-                          zone->spanned_pages,
-                          zone->present_pages);
+               page = pfn_to_page(pfn);
 
-               for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
-                       seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
-                                       zone_page_state(zone, i));
+               /* Watch for unexpected holes punched in the memmap */
+               if (!memmap_valid_within(pfn, 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 free pages at each order 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, pagetypeinfo_showblockcount_print);
+
+       return 0;
+}
+
+/*
+ * 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_HIGH_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);
+
+       return 0;
+}
+
+static const struct seq_operations fragmentation_op = {
+       .start  = frag_start,
+       .next   = frag_next,
+       .stop   = frag_stop,
+       .show   = frag_show,
+};
+
+static int fragmentation_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &fragmentation_op);
+}
+
+static const struct file_operations fragmentation_file_operations = {
+       .open           = fragmentation_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
+
+static const struct seq_operations pagetypeinfo_op = {
+       .start  = frag_start,
+       .next   = frag_next,
+       .stop   = frag_stop,
+       .show   = pagetypeinfo_show,
+};
+
+static int pagetypeinfo_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &pagetypeinfo_op);
+}
+
+static const struct file_operations pagetypeinfo_file_ops = {
+       .open           = pagetypeinfo_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
+
+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);
+       seq_printf(m,
+                  "\n  pages free     %lu"
+                  "\n        min      %lu"
+                  "\n        low      %lu"
+                  "\n        high     %lu"
+                  "\n        scanned  %lu"
+                  "\n        spanned  %lu"
+                  "\n        present  %lu",
+                  zone_page_state(zone, NR_FREE_PAGES),
+                  min_wmark_pages(zone),
+                  low_wmark_pages(zone),
+                  high_wmark_pages(zone),
+                  zone->pages_scanned,
+                  zone->spanned_pages,
+                  zone->present_pages);
+
+       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        protection: (%lu",
+                  zone->lowmem_reserve[0]);
+       for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
+               seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
+       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        protection: (%lu",
-                          zone->lowmem_reserve[0]);
-               for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
-                       seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
-               seq_printf(m,
-                          ")"
-                          "\n  pagesets");
-               for_each_online_cpu(i) {
-                       struct per_cpu_pageset *pageset;
-                       int j;
-
-                       pageset = zone_pcp(zone, i);
-                       for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
-                               seq_printf(m,
-                                          "\n    cpu: %i pcp: %i"
-                                          "\n              count: %i"
-                                          "\n              high:  %i"
-                                          "\n              batch: %i",
-                                          i, j,
-                                          pageset->pcp[j].count,
-                                          pageset->pcp[j].high,
-                                          pageset->pcp[j].batch);
-                       }
+                          "\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);
+               seq_printf(m, "\n  vm stats threshold: %d",
+                               pageset->stat_threshold);
 #endif
-               }
-               seq_printf(m,
-                          "\n  all_unreclaimable: %u"
-                          "\n  prev_priority:     %i"
-                          "\n  start_pfn:         %lu",
-                          zone->all_unreclaimable,
-                          zone->prev_priority,
-                          zone->zone_start_pfn);
-               spin_unlock_irqrestore(&zone->lock, flags);
-               seq_putc(m, '\n');
        }
+       seq_printf(m,
+                  "\n  all_unreclaimable: %u"
+                  "\n  start_pfn:         %lu"
+                  "\n  inactive_ratio:    %u",
+                  zone->all_unreclaimable,
+                  zone->zone_start_pfn,
+                  zone->inactive_ratio);
+       seq_putc(m, '\n');
+}
+
+/*
+ * Output information about zones in @pgdat.
+ */
+static int zoneinfo_show(struct seq_file *m, void *arg)
+{
+       pg_data_t *pgdat = (pg_data_t *)arg;
+       walk_zones_in_node(m, pgdat, zoneinfo_show_print);
        return 0;
 }
 
-const struct seq_operations zoneinfo_op = {
+static const struct seq_operations zoneinfo_op = {
        .start  = frag_start, /* iterate over all zones. The same as in
                               * fragmentation. */
        .next   = frag_next,
@@ -620,36 +1042,56 @@ const struct seq_operations zoneinfo_op = {
        .show   = zoneinfo_show,
 };
 
+static int zoneinfo_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &zoneinfo_op);
+}
+
+static const struct file_operations proc_zoneinfo_file_operations = {
+       .open           = zoneinfo_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
+
+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;
-#ifdef CONFIG_VM_EVENT_COUNTERS
-       unsigned long *e;
-#endif
-       int i;
+       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_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
 
 #ifdef CONFIG_VM_EVENT_COUNTERS
-       v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long)
-                       + sizeof(struct vm_event_state), GFP_KERNEL);
-#else
-       v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long),
-                       GFP_KERNEL);
+       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_page_state(i);
+       v += NR_VM_ZONE_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
-       e = v + NR_VM_ZONE_STAT_ITEMS;
-       all_vm_events(e);
-       e[PGPGIN] /= 2;         /* sectors -> kbytes */
-       e[PGPGOUT] /= 2;
+       all_vm_events(v);
+       v[PGPGIN] /= 2;         /* sectors -> kbytes */
+       v[PGPGOUT] /= 2;
 #endif
-       return v + *pos;
+       return (unsigned long *)m->private + *pos;
 }
 
 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
@@ -675,13 +1117,24 @@ static void vmstat_stop(struct seq_file *m, void *arg)
        m->private = NULL;
 }
 
-const struct seq_operations vmstat_op = {
+static const struct seq_operations vmstat_op = {
        .start  = vmstat_start,
        .next   = vmstat_next,
        .stop   = vmstat_stop,
        .show   = vmstat_show,
 };
 
+static int vmstat_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &vmstat_op);
+}
+
+static const struct file_operations proc_vmstat_file_operations = {
+       .open           = vmstat_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
 #endif /* CONFIG_PROC_FS */
 
 #ifdef CONFIG_SMP
@@ -692,15 +1145,15 @@ static void vmstat_update(struct work_struct *w)
 {
        refresh_cpu_vm_stats(smp_processor_id());
        schedule_delayed_work(&__get_cpu_var(vmstat_work),
-               sysctl_stat_interval);
+               round_jiffies_relative(sysctl_stat_interval));
 }
 
-static void __devinit start_cpu_timer(int cpu)
+static void __cpuinit start_cpu_timer(int cpu)
 {
-       struct delayed_work *vmstat_work = &per_cpu(vmstat_work, cpu);
+       struct delayed_work *work = &per_cpu(vmstat_work, cpu);
 
-       INIT_DELAYED_WORK_DEFERRABLE(vmstat_work, vmstat_update);
-       schedule_delayed_work_on(cpu, vmstat_work, HZ + cpu);
+       INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
+       schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
 }
 
 /*
@@ -716,11 +1169,13 @@ static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
        switch (action) {
        case CPU_ONLINE:
        case CPU_ONLINE_FROZEN:
+               refresh_zone_stat_thresholds();
                start_cpu_timer(cpu);
+               node_set_state(cpu_to_node(cpu), N_CPU);
                break;
        case CPU_DOWN_PREPARE:
        case CPU_DOWN_PREPARE_FROZEN:
-               cancel_rearming_delayed_work(&per_cpu(vmstat_work, cpu));
+               cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
                per_cpu(vmstat_work, cpu).work.func = NULL;
                break;
        case CPU_DOWN_FAILED:
@@ -739,17 +1194,183 @@ static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
 
 static struct notifier_block __cpuinitdata vmstat_notifier =
        { &vmstat_cpuup_callback, NULL, 0 };
+#endif
 
-int __init setup_vmstat(void)
+static int __init setup_vmstat(void)
 {
+#ifdef CONFIG_SMP
        int cpu;
 
-       refresh_zone_stat_thresholds();
        register_cpu_notifier(&vmstat_notifier);
 
        for_each_online_cpu(cpu)
                start_cpu_timer(cpu);
+#endif
+#ifdef CONFIG_PROC_FS
+       proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
+       proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
+       proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
+       proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
+#endif
        return 0;
 }
 module_init(setup_vmstat)
+
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
+#include <linux/debugfs.h>
+
+static struct dentry *extfrag_debug_root;
+
+/*
+ * 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_HIGH_MEMORY))
+               return 0;
+
+       walk_zones_in_node(m, pgdat, 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, 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)
+{
+       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))
+               return -ENOMEM;
+
+       if (!debugfs_create_file("extfrag_index", 0444,
+                       extfrag_debug_root, NULL, &extfrag_file_ops))
+               return -ENOMEM;
+
+       return 0;
+}
+
+module_init(extfrag_debug_init);
 #endif