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_softwall(int node, gfp_t gfp_mask);
  52 extern int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask);
  53
  54 static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
  55 {
  56         return nr_cpusets() <= 1 ||
  57                 __cpuset_node_allowed_softwall(node, gfp_mask);
  58 }
  59
  60 static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
  61 {
  62         return nr_cpusets() <= 1 ||
  63                 __cpuset_node_allowed_hardwall(node, gfp_mask);
  64 }
  65
  66 static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
  67 {
  68         return cpuset_node_allowed_softwall(zone_to_nid(z), gfp_mask);
  69 }
  70
  71 static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
  72 {
  73         return cpuset_node_allowed_hardwall(zone_to_nid(z), gfp_mask);
  74 }
  75
  76 extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
  77                                           const struct task_struct *tsk2);
  78
  79 #define cpuset_memory_pressure_bump()                           \
  80         do {                                                    \
  81                 if (cpuset_memory_pressure_enabled)             \
  82                         __cpuset_memory_pressure_bump();        \
  83         } while (0)
  84 extern int cpuset_memory_pressure_enabled;
  85 extern void __cpuset_memory_pressure_bump(void);
  86
  87 extern void cpuset_task_status_allowed(struct seq_file *m,
  88                                         struct task_struct *task);
  89 extern int proc_cpuset_show(struct seq_file *, void *);
  90
  91 extern int cpuset_mem_spread_node(void);
  92 extern int cpuset_slab_spread_node(void);
  93
  94 static inline int cpuset_do_page_mem_spread(void)
  95 {
  96         return current->flags & PF_SPREAD_PAGE;
  97 }
  98
  99 static inline int cpuset_do_slab_mem_spread(void)
 100 {
 101         return current->flags & PF_SPREAD_SLAB;
 102 }
 103
 104 extern int current_cpuset_is_being_rebound(void);
 105
 106 extern void rebuild_sched_domains(void);
 107
 108 extern void cpuset_print_task_mems_allowed(struct task_struct *p);
 109
 110 /*
 111  * read_mems_allowed_begin is required when making decisions involving
 112  * mems_allowed such as during page allocation. mems_allowed can be updated in
 113  * parallel and depending on the new value an operation can fail potentially
 114  * causing process failure. A retry loop with read_mems_allowed_begin and
 115  * read_mems_allowed_retry prevents these artificial failures.
 116  */
 117 static inline unsigned int read_mems_allowed_begin(void)
 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         return read_seqcount_retry(&current->mems_allowed_seq, seq);
 131 }
 132
 133 static inline void set_mems_allowed(nodemask_t nodemask)
 134 {
 135         unsigned long flags;
 136
 137         task_lock(current);
 138         local_irq_save(flags);
 139         write_seqcount_begin(&current->mems_allowed_seq);
 140         current->mems_allowed = nodemask;
 141         write_seqcount_end(&current->mems_allowed_seq);
 142         local_irq_restore(flags);
 143         task_unlock(current);
 144 }
 145
 146 #else /* !CONFIG_CPUSETS */
 147
 148 static inline bool cpusets_enabled(void) { return false; }
 149
 150 static inline int cpuset_init(void) { return 0; }
 151 static inline void cpuset_init_smp(void) {}
 152
 153 static inline void cpuset_update_active_cpus(bool cpu_online)
 154 {
 155         partition_sched_domains(1, NULL, NULL);
 156 }
 157
 158 static inline void cpuset_cpus_allowed(struct task_struct *p,
 159                                        struct cpumask *mask)
 160 {
 161         cpumask_copy(mask, cpu_possible_mask);
 162 }
 163
 164 static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
 165 {
 166 }
 167
 168 static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
 169 {
 170         return node_possible_map;
 171 }
 172
 173 #define cpuset_current_mems_allowed (node_states[N_MEMORY])
 174 static inline void cpuset_init_current_mems_allowed(void) {}
 175
 176 static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
 177 {
 178         return 1;
 179 }
 180
 181 static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
 182 {
 183         return 1;
 184 }
 185
 186 static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
 187 {
 188         return 1;
 189 }
 190
 191 static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
 192 {
 193         return 1;
 194 }
 195
 196 static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
 197 {
 198         return 1;
 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_task_mems_allowed(struct task_struct *p)
 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 */