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 cpusets_enabled_key;
  20static inline bool cpusets_enabled(void)
  21{
  22        return static_key_false(&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) + 1;
  29}
  30
  31static inline void cpuset_inc(void)
  32{
  33        static_key_slow_inc(&cpusets_enabled_key);
  34}
  35
  36static inline void cpuset_dec(void)
  37{
  38        static_key_slow_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 int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask);
  52extern int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask);
  53
  54static 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
  60static 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
  66static 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
  71static 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
  76extern 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)
  84extern int cpuset_memory_pressure_enabled;
  85extern void __cpuset_memory_pressure_bump(void);
  86
  87extern void cpuset_task_status_allowed(struct seq_file *m,
  88                                        struct task_struct *task);
  89extern int proc_cpuset_show(struct seq_file *, void *);
  90
  91extern int cpuset_mem_spread_node(void);
  92extern int cpuset_slab_spread_node(void);
  93
  94static inline int cpuset_do_page_mem_spread(void)
  95{
  96        return task_spread_page(current);
  97}
  98
  99static inline int cpuset_do_slab_mem_spread(void)
 100{
 101        return task_spread_slab(current);
 102}
 103
 104extern int current_cpuset_is_being_rebound(void);
 105
 106extern void rebuild_sched_domains(void);
 107
 108extern 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 */
 117static 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 */
 128static inline bool read_mems_allowed_retry(unsigned int seq)
 129{
 130        return read_seqcount_retry(&current->mems_allowed_seq, seq);
 131}
 132
 133static 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
 148static inline bool cpusets_enabled(void) { return false; }
 149
 150static inline int cpuset_init(void) { return 0; }
 151static inline void cpuset_init_smp(void) {}
 152
 153static inline void cpuset_update_active_cpus(bool cpu_online)
 154{
 155        partition_sched_domains(1, NULL, NULL);
 156}
 157
 158static inline void cpuset_cpus_allowed(struct task_struct *p,
 159                                       struct cpumask *mask)
 160{
 161        cpumask_copy(mask, cpu_possible_mask);
 162}
 163
 164static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
 165{
 166}
 167
 168static 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])
 174static inline void cpuset_init_current_mems_allowed(void) {}
 175
 176static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
 177{
 178        return 1;
 179}
 180
 181static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
 182{
 183        return 1;
 184}
 185
 186static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
 187{
 188        return 1;
 189}
 190
 191static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
 192{
 193        return 1;
 194}
 195
 196static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
 197{
 198        return 1;
 199}
 200
 201static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
 202                                                 const struct task_struct *tsk2)
 203{
 204        return 1;
 205}
 206
 207static inline void cpuset_memory_pressure_bump(void) {}
 208
 209static inline void cpuset_task_status_allowed(struct seq_file *m,
 210                                                struct task_struct *task)
 211{
 212}
 213
 214static inline int cpuset_mem_spread_node(void)
 215{
 216        return 0;
 217}
 218
 219static inline int cpuset_slab_spread_node(void)
 220{
 221        return 0;
 222}
 223
 224static inline int cpuset_do_page_mem_spread(void)
 225{
 226        return 0;
 227}
 228
 229static inline int cpuset_do_slab_mem_spread(void)
 230{
 231        return 0;
 232}
 233
 234static inline int current_cpuset_is_being_rebound(void)
 235{
 236        return 0;
 237}
 238
 239static inline void rebuild_sched_domains(void)
 240{
 241        partition_sched_domains(1, NULL, NULL);
 242}
 243
 244static inline void cpuset_print_task_mems_allowed(struct task_struct *p)
 245{
 246}
 247
 248static inline void set_mems_allowed(nodemask_t nodemask)
 249{
 250}
 251
 252static inline unsigned int read_mems_allowed_begin(void)
 253{
 254        return 0;
 255}
 256
 257static 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 */
 265