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 <asm/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 #ifdef CONFIG_HOTPLUG
  52 extern void vm_events_fold_cpu(int cpu);
  53 #else
  54 static inline void vm_events_fold_cpu(int cpu)
  55 {
  56 }
  57 #endif
  58
  59 #else
  60
  61 /* Disable counters */
  62 static inline void count_vm_event(enum vm_event_item item)
  63 {
  64 }
  65 static inline void count_vm_events(enum vm_event_item item, long delta)
  66 {
  67 }
  68 static inline void __count_vm_event(enum vm_event_item item)
  69 {
  70 }
  71 static inline void __count_vm_events(enum vm_event_item item, long delta)
  72 {
  73 }
  74 static inline void all_vm_events(unsigned long *ret)
  75 {
  76 }
  77 static inline void vm_events_fold_cpu(int cpu)
  78 {
  79 }
  80
  81 #endif /* CONFIG_VM_EVENT_COUNTERS */
  82
  83 #define __count_zone_vm_events(item, zone, delta) \
  84                 __count_vm_events(item##_NORMAL - ZONE_NORMAL + \
  85                 zone_idx(zone), delta)
  86
  87 /*
  88  * Zone based page accounting with per cpu differentials.
  89  */
  90 extern atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
  91
  92 static inline void zone_page_state_add(long x, struct zone *zone,
  93                                  enum zone_stat_item item)
  94 {
  95         atomic_long_add(x, &zone->vm_stat[item]);
  96         atomic_long_add(x, &vm_stat[item]);
  97 }
  98
  99 static inline unsigned long global_page_state(enum zone_stat_item item)
 100 {
 101         long x = atomic_long_read(&vm_stat[item]);
 102 #ifdef CONFIG_SMP
 103         if (x < 0)
 104                 x = 0;
 105 #endif
 106         return x;
 107 }
 108
 109 static inline unsigned long zone_page_state(struct zone *zone,
 110                                         enum zone_stat_item item)
 111 {
 112         long x = atomic_long_read(&zone->vm_stat[item]);
 113 #ifdef CONFIG_SMP
 114         if (x < 0)
 115                 x = 0;
 116 #endif
 117         return x;
 118 }
 119
 120 /*
 121  * More accurate version that also considers the currently pending
 122  * deltas. For that we need to loop over all cpus to find the current
 123  * deltas. There is no synchronization so the result cannot be
 124  * exactly accurate either.
 125  */
 126 static inline unsigned long zone_page_state_snapshot(struct zone *zone,
 127                                         enum zone_stat_item item)
 128 {
 129         long x = atomic_long_read(&zone->vm_stat[item]);
 130
 131 #ifdef CONFIG_SMP
 132         int cpu;
 133         for_each_online_cpu(cpu)
 134                 x += per_cpu_ptr(zone->pageset, cpu)->vm_stat_diff[item];
 135
 136         if (x < 0)
 137                 x = 0;
 138 #endif
 139         return x;
 140 }
 141
 142 extern unsigned long global_reclaimable_pages(void);
 143 extern unsigned long zone_reclaimable_pages(struct zone *zone);
 144
 145 #ifdef CONFIG_NUMA
 146 /*
 147  * Determine the per node value of a stat item. This function
 148  * is called frequently in a NUMA machine, so try to be as
 149  * frugal as possible.
 150  */
 151 static inline unsigned long node_page_state(int node,
 152                                  enum zone_stat_item item)
 153 {
 154         struct zone *zones = NODE_DATA(node)->node_zones;
 155
 156         return
 157 #ifdef CONFIG_ZONE_DMA
 158                 zone_page_state(&zones[ZONE_DMA], item) +
 159 #endif
 160 #ifdef CONFIG_ZONE_DMA32
 161                 zone_page_state(&zones[ZONE_DMA32], item) +
 162 #endif
 163 #ifdef CONFIG_HIGHMEM
 164                 zone_page_state(&zones[ZONE_HIGHMEM], item) +
 165 #endif
 166                 zone_page_state(&zones[ZONE_NORMAL], item) +
 167                 zone_page_state(&zones[ZONE_MOVABLE], item);
 168 }
 169
 170 extern void zone_statistics(struct zone *, struct zone *, gfp_t gfp);
 171
 172 #else
 173
 174 #define node_page_state(node, item) global_page_state(item)
 175 #define zone_statistics(_zl, _z, gfp) do { } while (0)
 176
 177 #endif /* CONFIG_NUMA */
 178
 179 #define add_zone_page_state(__z, __i, __d) mod_zone_page_state(__z, __i, __d)
 180 #define sub_zone_page_state(__z, __i, __d) mod_zone_page_state(__z, __i, -(__d))
 181
 182 static inline void zap_zone_vm_stats(struct zone *zone)
 183 {
 184         memset(zone->vm_stat, 0, sizeof(zone->vm_stat));
 185 }
 186
 187 extern void inc_zone_state(struct zone *, enum zone_stat_item);
 188
 189 #ifdef CONFIG_SMP
 190 void __mod_zone_page_state(struct zone *, enum zone_stat_item item, int);
 191 void __inc_zone_page_state(struct page *, enum zone_stat_item);
 192 void __dec_zone_page_state(struct page *, enum zone_stat_item);
 193
 194 void mod_zone_page_state(struct zone *, enum zone_stat_item, int);
 195 void inc_zone_page_state(struct page *, enum zone_stat_item);
 196 void dec_zone_page_state(struct page *, enum zone_stat_item);
 197
 198 extern void inc_zone_state(struct zone *, enum zone_stat_item);
 199 extern void __inc_zone_state(struct zone *, enum zone_stat_item);
 200 extern void dec_zone_state(struct zone *, enum zone_stat_item);
 201 extern void __dec_zone_state(struct zone *, enum zone_stat_item);
 202
 203 void refresh_cpu_vm_stats(int);
 204 void refresh_zone_stat_thresholds(void);
 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 #endif          /* CONFIG_SMP */
 260
 261 extern const char * const vmstat_text[];
 262
 263 #endif /* _LINUX_VMSTAT_H */