include/linux/cpuset.h

   1 #ifndef _LINUX_CPUSET_H
   2 #define _LINUX_CPUSET_H
   3 /*
   4  *  cpuset interface
   5  *
   6  *  Copyright (C) 2003 BULL SA
   7  *  Copyright (C) 2004-2006 Silicon Graphics, Inc.
   8  *
   9  */
  10
  11 #include <linux/sched.h>
  12 #include <linux/cpumask.h>
  13 #include <linux/nodemask.h>
  14 #include <linux/mm.h>
  15 #include <linux/jump_label.h>
  16
  17 #ifdef CONFIG_CPUSETS
  18
  19 extern struct static_key_false cpusets_enabled_key;
  20 static inline bool cpusets_enabled(void)
  21 {
  22         return static_branch_unlikely(&cpusets_enabled_key);
  23 }
  24
  25 static inline int nr_cpusets(void)
  26 {
  27         /* jump label reference count + the top-level cpuset */
  28         return static_key_count(&cpusets_enabled_key.key) + 1;
  29 }
  30
  31 static inline void cpuset_inc(void)
  32 {
  33         static_branch_inc(&cpusets_enabled_key);
  34 }
  35
  36 static inline void cpuset_dec(void)
  37 {
  38         static_branch_dec(&cpusets_enabled_key);
  39 }
  40
  41 extern int cpuset_init(void);
  42 extern void cpuset_init_smp(void);
  43 extern void cpuset_update_active_cpus(bool cpu_online);
  44 extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
  45 extern void cpuset_cpus_allowed_fallback(struct task_struct *p);
  46 extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
  47 #define cpuset_current_mems_allowed (current->mems_allowed)
  48 void cpuset_init_current_mems_allowed(void);
  49 int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask);
  50
  51 extern bool __cpuset_node_allowed(int node, gfp_t gfp_mask);
  52
  53 static inline bool cpuset_node_allowed(int node, gfp_t gfp_mask)
  54 {
  55         if (cpusets_enabled())
  56                 return __cpuset_node_allowed(node, gfp_mask);
  57         return true;
  58 }
  59
  60 static inline bool __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
  61 {
  62         return __cpuset_node_allowed(zone_to_nid(z), gfp_mask);
  63 }
  64
  65 static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
  66 {
  67         if (cpusets_enabled())
  68                 return __cpuset_zone_allowed(z, gfp_mask);
  69         return true;
  70 }
  71
  72 extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
  73                                           const struct task_struct *tsk2);
  74
  75 #define cpuset_memory_pressure_bump()                           \
  76         do {                                                    \
  77                 if (cpuset_memory_pressure_enabled)             \
  78                         __cpuset_memory_pressure_bump();        \
  79         } while (0)
  80 extern int cpuset_memory_pressure_enabled;
  81 extern void __cpuset_memory_pressure_bump(void);
  82
  83 extern void cpuset_task_status_allowed(struct seq_file *m,
  84                                         struct task_struct *task);
  85 extern int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
  86                             struct pid *pid, struct task_struct *tsk);
  87
  88 extern int cpuset_mem_spread_node(void);
  89 extern int cpuset_slab_spread_node(void);
  90
  91 static inline int cpuset_do_page_mem_spread(void)
  92 {
  93         return task_spread_page(current);
  94 }
  95
  96 static inline int cpuset_do_slab_mem_spread(void)
  97 {
  98         return task_spread_slab(current);
  99 }
 100
 101 extern int current_cpuset_is_being_rebound(void);
 102
 103 extern void rebuild_sched_domains(void);
 104
 105 extern void cpuset_print_current_mems_allowed(void);
 106
 107 /*
 108  * read_mems_allowed_begin is required when making decisions involving
 109  * mems_allowed such as during page allocation. mems_allowed can be updated in
 110  * parallel and depending on the new value an operation can fail potentially
 111  * causing process failure. A retry loop with read_mems_allowed_begin and
 112  * read_mems_allowed_retry prevents these artificial failures.
 113  */
 114 static inline unsigned int read_mems_allowed_begin(void)
 115 {
 116         if (!cpusets_enabled())
 117                 return 0;
 118
 119         return read_seqcount_begin(&current->mems_allowed_seq);
 120 }
 121
 122 /*
 123  * If this returns true, the operation that took place after
 124  * read_mems_allowed_begin may have failed artificially due to a concurrent
 125  * update of mems_allowed. It is up to the caller to retry the operation if
 126  * appropriate.
 127  */
 128 static inline bool read_mems_allowed_retry(unsigned int seq)
 129 {
 130         if (!cpusets_enabled())
 131                 return false;
 132
 133         return read_seqcount_retry(&current->mems_allowed_seq, seq);
 134 }
 135
 136 static inline void set_mems_allowed(nodemask_t nodemask)
 137 {
 138         unsigned long flags;
 139
 140         task_lock(current);
 141         local_irq_save(flags);
 142         write_seqcount_begin(&current->mems_allowed_seq);
 143         current->mems_allowed = nodemask;
 144         write_seqcount_end(&current->mems_allowed_seq);
 145         local_irq_restore(flags);
 146         task_unlock(current);
 147 }
 148
 149 #else /* !CONFIG_CPUSETS */
 150
 151 static inline bool cpusets_enabled(void) { return false; }
 152
 153 static inline int cpuset_init(void) { return 0; }
 154 static inline void cpuset_init_smp(void) {}
 155
 156 static inline void cpuset_update_active_cpus(bool cpu_online)
 157 {
 158         partition_sched_domains(1, NULL, NULL);
 159 }
 160
 161 static inline void cpuset_cpus_allowed(struct task_struct *p,
 162                                        struct cpumask *mask)
 163 {
 164         cpumask_copy(mask, cpu_possible_mask);
 165 }
 166
 167 static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
 168 {
 169 }
 170
 171 static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
 172 {
 173         return node_possible_map;
 174 }
 175
 176 #define cpuset_current_mems_allowed (node_states[N_MEMORY])
 177 static inline void cpuset_init_current_mems_allowed(void) {}
 178
 179 static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
 180 {
 181         return 1;
 182 }
 183
 184 static inline bool cpuset_node_allowed(int node, gfp_t gfp_mask)
 185 {
 186         return true;
 187 }
 188
 189 static inline bool __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
 190 {
 191         return true;
 192 }
 193
 194 static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
 195 {
 196         return true;
 197 }
 198
 199 static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
 200                                                  const struct task_struct *tsk2)
 201 {
 202         return 1;
 203 }
 204
 205 static inline void cpuset_memory_pressure_bump(void) {}
 206
 207 static inline void cpuset_task_status_allowed(struct seq_file *m,
 208                                                 struct task_struct *task)
 209 {
 210 }
 211
 212 static inline int cpuset_mem_spread_node(void)
 213 {
 214         return 0;
 215 }
 216
 217 static inline int cpuset_slab_spread_node(void)
 218 {
 219         return 0;
 220 }
 221
 222 static inline int cpuset_do_page_mem_spread(void)
 223 {
 224         return 0;
 225 }
 226
 227 static inline int cpuset_do_slab_mem_spread(void)
 228 {
 229         return 0;
 230 }
 231
 232 static inline int current_cpuset_is_being_rebound(void)
 233 {
 234         return 0;
 235 }
 236
 237 static inline void rebuild_sched_domains(void)
 238 {
 239         partition_sched_domains(1, NULL, NULL);
 240 }
 241
 242 static inline void cpuset_print_current_mems_allowed(void)
 243 {
 244 }
 245
 246 static inline void set_mems_allowed(nodemask_t nodemask)
 247 {
 248 }
 249
 250 static inline unsigned int read_mems_allowed_begin(void)
 251 {
 252         return 0;
 253 }
 254
 255 static inline bool read_mems_allowed_retry(unsigned int seq)
 256 {
 257         return false;
 258 }
 259
 260 #endif /* !CONFIG_CPUSETS */
 261
 262 #endif /* _LINUX_CPUSET_H */