+enum idle_type
+{
+ SCHED_IDLE,
+ NOT_IDLE,
+ NEWLY_IDLE,
+ MAX_IDLE_TYPES
+};
+
+/*
+ * sched-domains (multiprocessor balancing) declarations:
+ */
+#ifdef CONFIG_SMP
+#define SCHED_LOAD_SCALE 128UL /* increase resolution of load */
+
+#define SD_LOAD_BALANCE 1 /* Do load balancing on this domain. */
+#define SD_BALANCE_NEWIDLE 2 /* Balance when about to become idle */
+#define SD_BALANCE_EXEC 4 /* Balance on exec */
+#define SD_WAKE_IDLE 8 /* Wake to idle CPU on task wakeup */
+#define SD_WAKE_AFFINE 16 /* Wake task to waking CPU */
+#define SD_WAKE_BALANCE 32 /* Perform balancing at task wakeup */
+#define SD_SHARE_CPUPOWER 64 /* Domain members share cpu power */
+
+struct sched_group {
+ struct sched_group *next; /* Must be a circular list */
+ cpumask_t cpumask;
+
+ /*
+ * CPU power of this group, SCHED_LOAD_SCALE being max power for a
+ * single CPU. This is read only (except for setup, hotplug CPU).
+ */
+ unsigned long cpu_power;
+};
+
+struct sched_domain {
+ /* These fields must be setup */
+ struct sched_domain *parent; /* top domain must be null terminated */
+ struct sched_group *groups; /* the balancing groups of the domain */
+ cpumask_t span; /* span of all CPUs in this domain */
+ unsigned long min_interval; /* Minimum balance interval ms */
+ unsigned long max_interval; /* Maximum balance interval ms */
+ unsigned int busy_factor; /* less balancing by factor if busy */
+ unsigned int imbalance_pct; /* No balance until over watermark */
+ unsigned long long cache_hot_time; /* Task considered cache hot (ns) */
+ unsigned int cache_nice_tries; /* Leave cache hot tasks for # tries */
+ unsigned int per_cpu_gain; /* CPU % gained by adding domain cpus */
+ int flags; /* See SD_* */
+
+ /* Runtime fields. */
+ unsigned long last_balance; /* init to jiffies. units in jiffies */
+ unsigned int balance_interval; /* initialise to 1. units in ms. */
+ unsigned int nr_balance_failed; /* initialise to 0 */
+
+#ifdef CONFIG_SCHEDSTATS
+ /* load_balance() stats */
+ unsigned long lb_cnt[MAX_IDLE_TYPES];
+ unsigned long lb_failed[MAX_IDLE_TYPES];
+ unsigned long lb_imbalance[MAX_IDLE_TYPES];
+ unsigned long lb_nobusyg[MAX_IDLE_TYPES];
+ unsigned long lb_nobusyq[MAX_IDLE_TYPES];
+
+ /* sched_balance_exec() stats */
+ unsigned long sbe_attempts;
+ unsigned long sbe_pushed;
+
+ /* try_to_wake_up() stats */
+ unsigned long ttwu_wake_affine;
+ unsigned long ttwu_wake_balance;
+#endif
+};
+
+#ifdef ARCH_HAS_SCHED_DOMAIN
+/* Useful helpers that arch setup code may use. Defined in kernel/sched.c */
+extern cpumask_t cpu_isolated_map;
+extern void init_sched_build_groups(struct sched_group groups[],
+ cpumask_t span, int (*group_fn)(int cpu));
+extern void cpu_attach_domain(struct sched_domain *sd, int cpu);
+#endif /* ARCH_HAS_SCHED_DOMAIN */
+#endif /* CONFIG_SMP */
+
+