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/sched/topology.h>
  13 #include <linux/sched/task.h>
  14 #include <linux/cpumask.h>
  15 #include <linux/nodemask.h>
  16 #include <linux/mm.h>
  17 #include <linux/jump_label.h>
  18
  19 #ifdef CONFIG_CPUSETS
  20
  21 extern struct static_key_false cpusets_enabled_key;
  22 static inline bool cpusets_enabled(void)
  23 {
  24         return static_branch_unlikely(&cpusets_enabled_key);
  25 }
  26
  27 static inline int nr_cpusets(void)
  28 {
  29         /* jump label reference count + the top-level cpuset */
  30         return static_key_count(&cpusets_enabled_key.key) + 1;
  31 }
  32
  33 static inline void cpuset_inc(void)
  34 {
  35         static_branch_inc(&cpusets_enabled_key);
  36 }
  37
  38 static inline void cpuset_dec(void)
  39 {
  40         static_branch_dec(&cpusets_enabled_key);
  41 }
  42
  43 extern int cpuset_init(void);
  44 extern void cpuset_init_smp(void);
  45 extern void cpuset_update_active_cpus(void);
  46 extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
  47 extern void cpuset_cpus_allowed_fallback(struct task_struct *p);
  48 extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
  49 #define cpuset_current_mems_allowed (current->mems_allowed)
  50 void cpuset_init_current_mems_allowed(void);
  51 int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask);
  52
  53 extern bool __cpuset_node_allowed(int node, gfp_t gfp_mask);
  54
  55 static inline bool cpuset_node_allowed(int node, gfp_t gfp_mask)
  56 {
  57         if (cpusets_enabled())
  58                 return __cpuset_node_allowed(node, gfp_mask);
  59         return true;
  60 }
  61
  62 static inline bool __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
  63 {
  64         return __cpuset_node_allowed(zone_to_nid(z), gfp_mask);
  65 }
  66
  67 static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
  68 {
  69         if (cpusets_enabled())
  70                 return __cpuset_zone_allowed(z, gfp_mask);
  71         return true;
  72 }
  73
  74 extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
  75                                           const struct task_struct *tsk2);
  76
  77 #define cpuset_memory_pressure_bump()                           \
  78         do {                                                    \
  79                 if (cpuset_memory_pressure_enabled)             \
  80                         __cpuset_memory_pressure_bump();        \
  81         } while (0)
  82 extern int cpuset_memory_pressure_enabled;
  83 extern void __cpuset_memory_pressure_bump(void);
  84
  85 extern void cpuset_task_status_allowed(struct seq_file *m,
  86                                         struct task_struct *task);
  87 extern int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
  88                             struct pid *pid, struct task_struct *tsk);
  89
  90 extern int cpuset_mem_spread_node(void);
  91 extern int cpuset_slab_spread_node(void);
  92
  93 static inline int cpuset_do_page_mem_spread(void)
  94 {
  95         return task_spread_page(current);
  96 }
  97
  98 static inline int cpuset_do_slab_mem_spread(void)
  99 {
 100         return task_spread_slab(current);
 101 }
 102
 103 extern int current_cpuset_is_being_rebound(void);
 104
 105 extern void rebuild_sched_domains(void);
 106
 107 extern void cpuset_print_current_mems_allowed(void);
 108
 109 /*
 110  * read_mems_allowed_begin is required when making decisions involving
 111  * mems_allowed such as during page allocation. mems_allowed can be updated in
 112  * parallel and depending on the new value an operation can fail potentially
 113  * causing process failure. A retry loop with read_mems_allowed_begin and
 114  * read_mems_allowed_retry prevents these artificial failures.
 115  */
 116 static inline unsigned int read_mems_allowed_begin(void)
 117 {
 118         if (!cpusets_enabled())
 119                 return 0;
 120
 121         return read_seqcount_begin(&current->mems_allowed_seq);
 122 }
 123
 124 /*
 125  * If this returns true, the operation that took place after
 126  * read_mems_allowed_begin may have failed artificially due to a concurrent
 127  * update of mems_allowed. It is up to the caller to retry the operation if
 128  * appropriate.
 129  */
 130 static inline bool read_mems_allowed_retry(unsigned int seq)
 131 {
 132         if (!cpusets_enabled())
 133                 return false;
 134
 135         return read_seqcount_retry(&current->mems_allowed_seq, seq);
 136 }
 137
 138 static inline void set_mems_allowed(nodemask_t nodemask)
 139 {
 140         unsigned long flags;
 141
 142         task_lock(current);
 143         local_irq_save(flags);
 144         write_seqcount_begin(&current->mems_allowed_seq);
 145         current->mems_allowed = nodemask;
 146         write_seqcount_end(&current->mems_allowed_seq);
 147         local_irq_restore(flags);
 148         task_unlock(current);
 149 }
 150
 151 #else /* !CONFIG_CPUSETS */
 152
 153 static inline bool cpusets_enabled(void) { return false; }
 154
 155 static inline int cpuset_init(void) { return 0; }
 156 static inline void cpuset_init_smp(void) {}
 157
 158 static inline void cpuset_update_active_cpus(void)
 159 {
 160         partition_sched_domains(1, NULL, NULL);
 161 }
 162
 163 static inline void cpuset_cpus_allowed(struct task_struct *p,
 164                                        struct cpumask *mask)
 165 {
 166         cpumask_copy(mask, cpu_possible_mask);
 167 }
 168
 169 static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
 170 {
 171 }
 172
 173 static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
 174 {
 175         return node_possible_map;
 176 }
 177
 178 #define cpuset_current_mems_allowed (node_states[N_MEMORY])
 179 static inline void cpuset_init_current_mems_allowed(void) {}
 180
 181 static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
 182 {
 183         return 1;
 184 }
 185
 186 static inline bool cpuset_node_allowed(int node, gfp_t gfp_mask)
 187 {
 188         return true;
 189 }
 190
 191 static inline bool __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
 192 {
 193         return true;
 194 }
 195
 196 static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
 197 {
 198         return true;
 199 }
 200
 201 static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
 202                                                  const struct task_struct *tsk2)
 203 {
 204         return 1;
 205 }
 206
 207 static inline void cpuset_memory_pressure_bump(void) {}
 208
 209 static inline void cpuset_task_status_allowed(struct seq_file *m,
 210                                                 struct task_struct *task)
 211 {
 212 }
 213
 214 static inline int cpuset_mem_spread_node(void)
 215 {
 216         return 0;
 217 }
 218
 219 static inline int cpuset_slab_spread_node(void)
 220 {
 221         return 0;
 222 }
 223
 224 static inline int cpuset_do_page_mem_spread(void)
 225 {
 226         return 0;
 227 }
 228
 229 static inline int cpuset_do_slab_mem_spread(void)
 230 {
 231         return 0;
 232 }
 233
 234 static inline int current_cpuset_is_being_rebound(void)
 235 {
 236         return 0;
 237 }
 238
 239 static inline void rebuild_sched_domains(void)
 240 {
 241         partition_sched_domains(1, NULL, NULL);
 242 }
 243
 244 static inline void cpuset_print_current_mems_allowed(void)
 245 {
 246 }
 247
 248 static inline void set_mems_allowed(nodemask_t nodemask)
 249 {
 250 }
 251
 252 static inline unsigned int read_mems_allowed_begin(void)
 253 {
 254         return 0;
 255 }
 256
 257 static inline bool read_mems_allowed_retry(unsigned int seq)
 258 {
 259         return false;
 260 }
 261
 262 #endif /* !CONFIG_CPUSETS */
 263
 264 #endif /* _LINUX_CPUSET_H */