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