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 *m, struct pid_namespace *ns,
  90                             struct pid *pid, struct task_struct *tsk);
  91
  92 extern int cpuset_mem_spread_node(void);
  93 extern int cpuset_slab_spread_node(void);
  94
  95 static inline int cpuset_do_page_mem_spread(void)
  96 {
  97         return task_spread_page(current);
  98 }
  99
 100 static inline int cpuset_do_slab_mem_spread(void)
 101 {
 102         return task_spread_slab(current);
 103 }
 104
 105 extern int current_cpuset_is_being_rebound(void);
 106
 107 extern void rebuild_sched_domains(void);
 108
 109 extern void cpuset_print_task_mems_allowed(struct task_struct *p);
 110
 111 /*
 112  * read_mems_allowed_begin is required when making decisions involving
 113  * mems_allowed such as during page allocation. mems_allowed can be updated in
 114  * parallel and depending on the new value an operation can fail potentially
 115  * causing process failure. A retry loop with read_mems_allowed_begin and
 116  * read_mems_allowed_retry prevents these artificial failures.
 117  */
 118 static inline unsigned int read_mems_allowed_begin(void)
 119 {
 120         return read_seqcount_begin(&current->mems_allowed_seq);
 121 }
 122
 123 /*
 124  * If this returns true, the operation that took place after
 125  * read_mems_allowed_begin may have failed artificially due to a concurrent
 126  * update of mems_allowed. It is up to the caller to retry the operation if
 127  * appropriate.
 128  */
 129 static inline bool read_mems_allowed_retry(unsigned int seq)
 130 {
 131         return read_seqcount_retry(&current->mems_allowed_seq, seq);
 132 }
 133
 134 static inline void set_mems_allowed(nodemask_t nodemask)
 135 {
 136         unsigned long flags;
 137
 138         task_lock(current);
 139         local_irq_save(flags);
 140         write_seqcount_begin(&current->mems_allowed_seq);
 141         current->mems_allowed = nodemask;
 142         write_seqcount_end(&current->mems_allowed_seq);
 143         local_irq_restore(flags);
 144         task_unlock(current);
 145 }
 146
 147 #else /* !CONFIG_CPUSETS */
 148
 149 static inline bool cpusets_enabled(void) { return false; }
 150
 151 static inline int cpuset_init(void) { return 0; }
 152 static inline void cpuset_init_smp(void) {}
 153
 154 static inline void cpuset_update_active_cpus(bool cpu_online)
 155 {
 156         partition_sched_domains(1, NULL, NULL);
 157 }
 158
 159 static inline void cpuset_cpus_allowed(struct task_struct *p,
 160                                        struct cpumask *mask)
 161 {
 162         cpumask_copy(mask, cpu_possible_mask);
 163 }
 164
 165 static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
 166 {
 167 }
 168
 169 static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
 170 {
 171         return node_possible_map;
 172 }
 173
 174 #define cpuset_current_mems_allowed (node_states[N_MEMORY])
 175 static inline void cpuset_init_current_mems_allowed(void) {}
 176
 177 static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
 178 {
 179         return 1;
 180 }
 181
 182 static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
 183 {
 184         return 1;
 185 }
 186
 187 static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
 188 {
 189         return 1;
 190 }
 191
 192 static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
 193 {
 194         return 1;
 195 }
 196
 197 static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
 198 {
 199         return 1;
 200 }
 201
 202 static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
 203                                                  const struct task_struct *tsk2)
 204 {
 205         return 1;
 206 }
 207
 208 static inline void cpuset_memory_pressure_bump(void) {}
 209
 210 static inline void cpuset_task_status_allowed(struct seq_file *m,
 211                                                 struct task_struct *task)
 212 {
 213 }
 214
 215 static inline int cpuset_mem_spread_node(void)
 216 {
 217         return 0;
 218 }
 219
 220 static inline int cpuset_slab_spread_node(void)
 221 {
 222         return 0;
 223 }
 224
 225 static inline int cpuset_do_page_mem_spread(void)
 226 {
 227         return 0;
 228 }
 229
 230 static inline int cpuset_do_slab_mem_spread(void)
 231 {
 232         return 0;
 233 }
 234
 235 static inline int current_cpuset_is_being_rebound(void)
 236 {
 237         return 0;
 238 }
 239
 240 static inline void rebuild_sched_domains(void)
 241 {
 242         partition_sched_domains(1, NULL, NULL);
 243 }
 244
 245 static inline void cpuset_print_task_mems_allowed(struct task_struct *p)
 246 {
 247 }
 248
 249 static inline void set_mems_allowed(nodemask_t nodemask)
 250 {
 251 }
 252
 253 static inline unsigned int read_mems_allowed_begin(void)
 254 {
 255         return 0;
 256 }
 257
 258 static inline bool read_mems_allowed_retry(unsigned int seq)
 259 {
 260         return false;
 261 }
 262
 263 #endif /* !CONFIG_CPUSETS */
 264
 265 #endif /* _LINUX_CPUSET_H */