linux/include/linux/cpuset.h
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   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
  19extern struct static_key_false cpusets_enabled_key;
  20static inline bool cpusets_enabled(void)
  21{
  22        return static_branch_unlikely(&cpusets_enabled_key);
  23}
  24
  25static 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
  31static inline void cpuset_inc(void)
  32{
  33        static_branch_inc(&cpusets_enabled_key);
  34}
  35
  36static inline void cpuset_dec(void)
  37{
  38        static_branch_dec(&cpusets_enabled_key);
  39}
  40
  41extern int cpuset_init(void);
  42extern void cpuset_init_smp(void);
  43extern void cpuset_update_active_cpus(bool cpu_online);
  44extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
  45extern void cpuset_cpus_allowed_fallback(struct task_struct *p);
  46extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
  47#define cpuset_current_mems_allowed (current->mems_allowed)
  48void cpuset_init_current_mems_allowed(void);
  49int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask);
  50
  51extern bool __cpuset_node_allowed(int node, gfp_t gfp_mask);
  52
  53static 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
  60static 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
  65static 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
  72extern 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)
  80extern int cpuset_memory_pressure_enabled;
  81extern void __cpuset_memory_pressure_bump(void);
  82
  83extern void cpuset_task_status_allowed(struct seq_file *m,
  84                                        struct task_struct *task);
  85extern int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
  86                            struct pid *pid, struct task_struct *tsk);
  87
  88extern int cpuset_mem_spread_node(void);
  89extern int cpuset_slab_spread_node(void);
  90
  91static inline int cpuset_do_page_mem_spread(void)
  92{
  93        return task_spread_page(current);
  94}
  95
  96static inline int cpuset_do_slab_mem_spread(void)
  97{
  98        return task_spread_slab(current);
  99}
 100
 101extern int current_cpuset_is_being_rebound(void);
 102
 103extern void rebuild_sched_domains(void);
 104
 105extern 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 */
 114static 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 */
 128static 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
 136static 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
 151static inline bool cpusets_enabled(void) { return false; }
 152
 153static inline int cpuset_init(void) { return 0; }
 154static inline void cpuset_init_smp(void) {}
 155
 156static inline void cpuset_update_active_cpus(bool cpu_online)
 157{
 158        partition_sched_domains(1, NULL, NULL);
 159}
 160
 161static inline void cpuset_cpus_allowed(struct task_struct *p,
 162                                       struct cpumask *mask)
 163{
 164        cpumask_copy(mask, cpu_possible_mask);
 165}
 166
 167static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
 168{
 169}
 170
 171static 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])
 177static inline void cpuset_init_current_mems_allowed(void) {}
 178
 179static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
 180{
 181        return 1;
 182}
 183
 184static inline bool cpuset_node_allowed(int node, gfp_t gfp_mask)
 185{
 186        return true;
 187}
 188
 189static inline bool __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
 190{
 191        return true;
 192}
 193
 194static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
 195{
 196        return true;
 197}
 198
 199static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
 200                                                 const struct task_struct *tsk2)
 201{
 202        return 1;
 203}
 204
 205static inline void cpuset_memory_pressure_bump(void) {}
 206
 207static inline void cpuset_task_status_allowed(struct seq_file *m,
 208                                                struct task_struct *task)
 209{
 210}
 211
 212static inline int cpuset_mem_spread_node(void)
 213{
 214        return 0;
 215}
 216
 217static inline int cpuset_slab_spread_node(void)
 218{
 219        return 0;
 220}
 221
 222static inline int cpuset_do_page_mem_spread(void)
 223{
 224        return 0;
 225}
 226
 227static inline int cpuset_do_slab_mem_spread(void)
 228{
 229        return 0;
 230}
 231
 232static inline int current_cpuset_is_being_rebound(void)
 233{
 234        return 0;
 235}
 236
 237static inline void rebuild_sched_domains(void)
 238{
 239        partition_sched_domains(1, NULL, NULL);
 240}
 241
 242static inline void cpuset_print_current_mems_allowed(void)
 243{
 244}
 245
 246static inline void set_mems_allowed(nodemask_t nodemask)
 247{
 248}
 249
 250static inline unsigned int read_mems_allowed_begin(void)
 251{
 252        return 0;
 253}
 254
 255static 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 */
 263