xref: /openbmc/linux/include/linux/sched/topology.h (revision b830f94f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SCHED_TOPOLOGY_H
3 #define _LINUX_SCHED_TOPOLOGY_H
4 
5 #include <linux/topology.h>
6 
7 #include <linux/sched/idle.h>
8 
9 /*
10  * sched-domains (multiprocessor balancing) declarations:
11  */
12 #ifdef CONFIG_SMP
13 
14 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
15 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
16 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
17 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
18 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
19 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
20 #define SD_ASYM_CPUCAPACITY	0x0040  /* Domain members have different CPU capacities */
21 #define SD_SHARE_CPUCAPACITY	0x0080	/* Domain members share CPU capacity */
22 #define SD_SHARE_POWERDOMAIN	0x0100	/* Domain members share power domain */
23 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share CPU pkg resources */
24 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
25 #define SD_ASYM_PACKING		0x0800  /* Place busy groups earlier in the domain */
26 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
27 #define SD_OVERLAP		0x2000	/* sched_domains of this level overlap */
28 #define SD_NUMA			0x4000	/* cross-node balancing */
29 
30 #ifdef CONFIG_SCHED_SMT
31 static inline int cpu_smt_flags(void)
32 {
33 	return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
34 }
35 #endif
36 
37 #ifdef CONFIG_SCHED_MC
38 static inline int cpu_core_flags(void)
39 {
40 	return SD_SHARE_PKG_RESOURCES;
41 }
42 #endif
43 
44 #ifdef CONFIG_NUMA
45 static inline int cpu_numa_flags(void)
46 {
47 	return SD_NUMA;
48 }
49 #endif
50 
51 extern int arch_asym_cpu_priority(int cpu);
52 
53 struct sched_domain_attr {
54 	int relax_domain_level;
55 };
56 
57 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
58 	.relax_domain_level = -1,			\
59 }
60 
61 extern int sched_domain_level_max;
62 
63 struct sched_group;
64 
65 struct sched_domain_shared {
66 	atomic_t	ref;
67 	atomic_t	nr_busy_cpus;
68 	int		has_idle_cores;
69 };
70 
71 struct sched_domain {
72 	/* These fields must be setup */
73 	struct sched_domain __rcu *parent;	/* top domain must be null terminated */
74 	struct sched_domain __rcu *child;	/* bottom domain must be null terminated */
75 	struct sched_group *groups;	/* the balancing groups of the domain */
76 	unsigned long min_interval;	/* Minimum balance interval ms */
77 	unsigned long max_interval;	/* Maximum balance interval ms */
78 	unsigned int busy_factor;	/* less balancing by factor if busy */
79 	unsigned int imbalance_pct;	/* No balance until over watermark */
80 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
81 
82 	int nohz_idle;			/* NOHZ IDLE status */
83 	int flags;			/* See SD_* */
84 	int level;
85 
86 	/* Runtime fields. */
87 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
88 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
89 	unsigned int nr_balance_failed; /* initialise to 0 */
90 
91 	/* idle_balance() stats */
92 	u64 max_newidle_lb_cost;
93 	unsigned long next_decay_max_lb_cost;
94 
95 	u64 avg_scan_cost;		/* select_idle_sibling */
96 
97 #ifdef CONFIG_SCHEDSTATS
98 	/* load_balance() stats */
99 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
100 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
101 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
102 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
103 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
104 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
105 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
106 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
107 
108 	/* Active load balancing */
109 	unsigned int alb_count;
110 	unsigned int alb_failed;
111 	unsigned int alb_pushed;
112 
113 	/* SD_BALANCE_EXEC stats */
114 	unsigned int sbe_count;
115 	unsigned int sbe_balanced;
116 	unsigned int sbe_pushed;
117 
118 	/* SD_BALANCE_FORK stats */
119 	unsigned int sbf_count;
120 	unsigned int sbf_balanced;
121 	unsigned int sbf_pushed;
122 
123 	/* try_to_wake_up() stats */
124 	unsigned int ttwu_wake_remote;
125 	unsigned int ttwu_move_affine;
126 	unsigned int ttwu_move_balance;
127 #endif
128 #ifdef CONFIG_SCHED_DEBUG
129 	char *name;
130 #endif
131 	union {
132 		void *private;		/* used during construction */
133 		struct rcu_head rcu;	/* used during destruction */
134 	};
135 	struct sched_domain_shared *shared;
136 
137 	unsigned int span_weight;
138 	/*
139 	 * Span of all CPUs in this domain.
140 	 *
141 	 * NOTE: this field is variable length. (Allocated dynamically
142 	 * by attaching extra space to the end of the structure,
143 	 * depending on how many CPUs the kernel has booted up with)
144 	 */
145 	unsigned long span[0];
146 };
147 
148 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
149 {
150 	return to_cpumask(sd->span);
151 }
152 
153 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
154 				    struct sched_domain_attr *dattr_new);
155 
156 /* Allocate an array of sched domains, for partition_sched_domains(). */
157 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
158 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
159 
160 bool cpus_share_cache(int this_cpu, int that_cpu);
161 
162 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
163 typedef int (*sched_domain_flags_f)(void);
164 
165 #define SDTL_OVERLAP	0x01
166 
167 struct sd_data {
168 	struct sched_domain *__percpu *sd;
169 	struct sched_domain_shared *__percpu *sds;
170 	struct sched_group *__percpu *sg;
171 	struct sched_group_capacity *__percpu *sgc;
172 };
173 
174 struct sched_domain_topology_level {
175 	sched_domain_mask_f mask;
176 	sched_domain_flags_f sd_flags;
177 	int		    flags;
178 	int		    numa_level;
179 	struct sd_data      data;
180 #ifdef CONFIG_SCHED_DEBUG
181 	char                *name;
182 #endif
183 };
184 
185 extern void set_sched_topology(struct sched_domain_topology_level *tl);
186 
187 #ifdef CONFIG_SCHED_DEBUG
188 # define SD_INIT_NAME(type)		.name = #type
189 #else
190 # define SD_INIT_NAME(type)
191 #endif
192 
193 #else /* CONFIG_SMP */
194 
195 struct sched_domain_attr;
196 
197 static inline void
198 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
199 			struct sched_domain_attr *dattr_new)
200 {
201 }
202 
203 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
204 {
205 	return true;
206 }
207 
208 #endif	/* !CONFIG_SMP */
209 
210 #ifndef arch_scale_cpu_capacity
211 static __always_inline
212 unsigned long arch_scale_cpu_capacity(int cpu)
213 {
214 	return SCHED_CAPACITY_SCALE;
215 }
216 #endif
217 
218 static inline int task_node(const struct task_struct *p)
219 {
220 	return cpu_to_node(task_cpu(p));
221 }
222 
223 #endif /* _LINUX_SCHED_TOPOLOGY_H */
224