include/linux/vmstat.h

   1 #ifndef _LINUX_VMSTAT_H
   2 #define _LINUX_VMSTAT_H
   3
   4 #include <linux/types.h>
   5 #include <linux/percpu.h>
   6 #include <linux/mm.h>
   7 #include <linux/mmzone.h>
   8 #include <linux/vm_event_item.h>
   9 #include <linux/atomic.h>
  10
  11 extern int sysctl_stat_interval;
  12
  13 #ifdef CONFIG_VM_EVENT_COUNTERS
  14 /*
  15  * Light weight per cpu counter implementation.
  16  *
  17  * Counters should only be incremented and no critical kernel component
  18  * should rely on the counter values.
  19  *
  20  * Counters are handled completely inline. On many platforms the code
  21  * generated will simply be the increment of a global address.
  22  */
  23
  24 struct vm_event_state {
  25         unsigned long event[NR_VM_EVENT_ITEMS];
  26 };
  27
  28 DECLARE_PER_CPU(struct vm_event_state, vm_event_states);
  29
  30 static inline void __count_vm_event(enum vm_event_item item)
  31 {
  32         __this_cpu_inc(vm_event_states.event[item]);
  33 }
  34
  35 static inline void count_vm_event(enum vm_event_item item)
  36 {
  37         this_cpu_inc(vm_event_states.event[item]);
  38 }
  39
  40 static inline void __count_vm_events(enum vm_event_item item, long delta)
  41 {
  42         __this_cpu_add(vm_event_states.event[item], delta);
  43 }
  44
  45 static inline void count_vm_events(enum vm_event_item item, long delta)
  46 {
  47         this_cpu_add(vm_event_states.event[item], delta);
  48 }
  49
  50 extern void all_vm_events(unsigned long *);
  51
  52 extern void vm_events_fold_cpu(int cpu);
  53
  54 #else
  55
  56 /* Disable counters */
  57 static inline void count_vm_event(enum vm_event_item item)
  58 {
  59 }
  60 static inline void count_vm_events(enum vm_event_item item, long delta)
  61 {
  62 }
  63 static inline void __count_vm_event(enum vm_event_item item)
  64 {
  65 }
  66 static inline void __count_vm_events(enum vm_event_item item, long delta)
  67 {
  68 }
  69 static inline void all_vm_events(unsigned long *ret)
  70 {
  71 }
  72 static inline void vm_events_fold_cpu(int cpu)
  73 {
  74 }
  75
  76 #endif /* CONFIG_VM_EVENT_COUNTERS */
  77
  78 #ifdef CONFIG_NUMA_BALANCING
  79 #define count_vm_numa_event(x)     count_vm_event(x)
  80 #define count_vm_numa_events(x, y) count_vm_events(x, y)
  81 #else
  82 #define count_vm_numa_event(x) do {} while (0)
  83 #define count_vm_numa_events(x, y) do { (void)(y); } while (0)
  84 #endif /* CONFIG_NUMA_BALANCING */
  85
  86 #define __count_zone_vm_events(item, zone, delta) \
  87                 __count_vm_events(item##_NORMAL - ZONE_NORMAL + \
  88                 zone_idx(zone), delta)
  89
  90 /*
  91  * Zone based page accounting with per cpu differentials.
  92  */
  93 extern atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
  94
  95 static inline void zone_page_state_add(long x, struct zone *zone,
  96                                  enum zone_stat_item item)
  97 {
  98         atomic_long_add(x, &zone->vm_stat[item]);
  99         atomic_long_add(x, &vm_stat[item]);
 100 }
 101
 102 static inline unsigned long global_page_state(enum zone_stat_item item)
 103 {
 104         long x = atomic_long_read(&vm_stat[item]);
 105 #ifdef CONFIG_SMP
 106         if (x < 0)
 107                 x = 0;
 108 #endif
 109         return x;
 110 }
 111
 112 static inline unsigned long zone_page_state(struct zone *zone,
 113                                         enum zone_stat_item item)
 114 {
 115         long x = atomic_long_read(&zone->vm_stat[item]);
 116 #ifdef CONFIG_SMP
 117         if (x < 0)
 118                 x = 0;
 119 #endif
 120         return x;
 121 }
 122
 123 /*
 124  * More accurate version that also considers the currently pending
 125  * deltas. For that we need to loop over all cpus to find the current
 126  * deltas. There is no synchronization so the result cannot be
 127  * exactly accurate either.
 128  */
 129 static inline unsigned long zone_page_state_snapshot(struct zone *zone,
 130                                         enum zone_stat_item item)
 131 {
 132         long x = atomic_long_read(&zone->vm_stat[item]);
 133
 134 #ifdef CONFIG_SMP
 135         int cpu;
 136         for_each_online_cpu(cpu)
 137                 x += per_cpu_ptr(zone->pageset, cpu)->vm_stat_diff[item];
 138
 139         if (x < 0)
 140                 x = 0;
 141 #endif
 142         return x;
 143 }
 144
 145 extern unsigned long global_reclaimable_pages(void);
 146 extern unsigned long zone_reclaimable_pages(struct zone *zone);
 147
 148 #ifdef CONFIG_NUMA
 149 /*
 150  * Determine the per node value of a stat item. This function
 151  * is called frequently in a NUMA machine, so try to be as
 152  * frugal as possible.
 153  */
 154 static inline unsigned long node_page_state(int node,
 155                                  enum zone_stat_item item)
 156 {
 157         struct zone *zones = NODE_DATA(node)->node_zones;
 158
 159         return
 160 #ifdef CONFIG_ZONE_DMA
 161                 zone_page_state(&zones[ZONE_DMA], item) +
 162 #endif
 163 #ifdef CONFIG_ZONE_DMA32
 164                 zone_page_state(&zones[ZONE_DMA32], item) +
 165 #endif
 166 #ifdef CONFIG_HIGHMEM
 167                 zone_page_state(&zones[ZONE_HIGHMEM], item) +
 168 #endif
 169                 zone_page_state(&zones[ZONE_NORMAL], item) +
 170                 zone_page_state(&zones[ZONE_MOVABLE], item);
 171 }
 172
 173 extern void zone_statistics(struct zone *, struct zone *, gfp_t gfp);
 174
 175 #else
 176
 177 #define node_page_state(node, item) global_page_state(item)
 178 #define zone_statistics(_zl, _z, gfp) do { } while (0)
 179
 180 #endif /* CONFIG_NUMA */
 181
 182 #define add_zone_page_state(__z, __i, __d) mod_zone_page_state(__z, __i, __d)
 183 #define sub_zone_page_state(__z, __i, __d) mod_zone_page_state(__z, __i, -(__d))
 184
 185 extern void inc_zone_state(struct zone *, enum zone_stat_item);
 186
 187 #ifdef CONFIG_SMP
 188 void __mod_zone_page_state(struct zone *, enum zone_stat_item item, int);
 189 void __inc_zone_page_state(struct page *, enum zone_stat_item);
 190 void __dec_zone_page_state(struct page *, enum zone_stat_item);
 191
 192 void mod_zone_page_state(struct zone *, enum zone_stat_item, int);
 193 void inc_zone_page_state(struct page *, enum zone_stat_item);
 194 void dec_zone_page_state(struct page *, enum zone_stat_item);
 195
 196 extern void inc_zone_state(struct zone *, enum zone_stat_item);
 197 extern void __inc_zone_state(struct zone *, enum zone_stat_item);
 198 extern void dec_zone_state(struct zone *, enum zone_stat_item);
 199 extern void __dec_zone_state(struct zone *, enum zone_stat_item);
 200
 201 void refresh_cpu_vm_stats(int);
 202 void refresh_zone_stat_thresholds(void);
 203
 204 void drain_zonestat(struct zone *zone, struct per_cpu_pageset *);
 205
 206 int calculate_pressure_threshold(struct zone *zone);
 207 int calculate_normal_threshold(struct zone *zone);
 208 void set_pgdat_percpu_threshold(pg_data_t *pgdat,
 209                                 int (*calculate_pressure)(struct zone *));
 210 #else /* CONFIG_SMP */
 211
 212 /*
 213  * We do not maintain differentials in a single processor configuration.
 214  * The functions directly modify the zone and global counters.
 215  */
 216 static inline void __mod_zone_page_state(struct zone *zone,
 217                         enum zone_stat_item item, int delta)
 218 {
 219         zone_page_state_add(delta, zone, item);
 220 }
 221
 222 static inline void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
 223 {
 224         atomic_long_inc(&zone->vm_stat[item]);
 225         atomic_long_inc(&vm_stat[item]);
 226 }
 227
 228 static inline void __inc_zone_page_state(struct page *page,
 229                         enum zone_stat_item item)
 230 {
 231         __inc_zone_state(page_zone(page), item);
 232 }
 233
 234 static inline void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
 235 {
 236         atomic_long_dec(&zone->vm_stat[item]);
 237         atomic_long_dec(&vm_stat[item]);
 238 }
 239
 240 static inline void __dec_zone_page_state(struct page *page,
 241                         enum zone_stat_item item)
 242 {
 243         __dec_zone_state(page_zone(page), item);
 244 }
 245
 246 /*
 247  * We only use atomic operations to update counters. So there is no need to
 248  * disable interrupts.
 249  */
 250 #define inc_zone_page_state __inc_zone_page_state
 251 #define dec_zone_page_state __dec_zone_page_state
 252 #define mod_zone_page_state __mod_zone_page_state
 253
 254 #define set_pgdat_percpu_threshold(pgdat, callback) { }
 255
 256 static inline void refresh_cpu_vm_stats(int cpu) { }
 257 static inline void refresh_zone_stat_thresholds(void) { }
 258
 259 static inline void drain_zonestat(struct zone *zone,
 260                         struct per_cpu_pageset *pset) { }
 261 #endif          /* CONFIG_SMP */
 262
 263 static inline void __mod_zone_freepage_state(struct zone *zone, int nr_pages,
 264                                              int migratetype)
 265 {
 266         __mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
 267         if (is_migrate_cma(migratetype))
 268                 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, nr_pages);
 269 }
 270
 271 extern const char * const vmstat_text[];
 272
 273 #endif /* _LINUX_VMSTAT_H */