hc
2024-05-13 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e
kernel/include/linux/energy_model.h
....@@ -2,6 +2,7 @@
22 #ifndef _LINUX_ENERGY_MODEL_H
33 #define _LINUX_ENERGY_MODEL_H
44 #include <linux/cpumask.h>
5
+#include <linux/device.h>
56 #include <linux/jump_label.h>
67 #include <linux/kobject.h>
78 #include <linux/rcupdate.h>
....@@ -9,15 +10,16 @@
910 #include <linux/sched/topology.h>
1011 #include <linux/types.h>
1112
12
-#ifdef CONFIG_ENERGY_MODEL
1313 /**
14
- * em_cap_state - Capacity state of a performance domain
15
- * @frequency: The CPU frequency in KHz, for consistency with CPUFreq
16
- * @power: The power consumed by 1 CPU at this level, in milli-watts
14
+ * em_perf_state - Performance state of a performance domain
15
+ * @frequency: The frequency in KHz, for consistency with CPUFreq
16
+ * @power: The power consumed at this level, in milli-watts (by 1 CPU or
17
+ by a registered device). It can be a total power: static and
18
+ dynamic.
1719 * @cost: The cost coefficient associated with this level, used during
1820 * energy calculation. Equal to: power * max_frequency / frequency
1921 */
20
-struct em_cap_state {
22
+struct em_perf_state {
2123 unsigned long frequency;
2224 unsigned long power;
2325 unsigned long cost;
....@@ -25,101 +27,142 @@
2527
2628 /**
2729 * em_perf_domain - Performance domain
28
- * @table: List of capacity states, in ascending order
29
- * @nr_cap_states: Number of capacity states
30
- * @cpus: Cpumask covering the CPUs of the domain
30
+ * @table: List of performance states, in ascending order
31
+ * @nr_perf_states: Number of performance states
32
+ * @milliwatts: Flag indicating the power values are in milli-Watts
33
+ * or some other scale.
34
+ * @cpus: Cpumask covering the CPUs of the domain. It's here
35
+ * for performance reasons to avoid potential cache
36
+ * misses during energy calculations in the scheduler
37
+ * and simplifies allocating/freeing that memory region.
3138 *
32
- * A "performance domain" represents a group of CPUs whose performance is
33
- * scaled together. All CPUs of a performance domain must have the same
34
- * micro-architecture. Performance domains often have a 1-to-1 mapping with
35
- * CPUFreq policies.
39
+ * In case of CPU device, a "performance domain" represents a group of CPUs
40
+ * whose performance is scaled together. All CPUs of a performance domain
41
+ * must have the same micro-architecture. Performance domains often have
42
+ * a 1-to-1 mapping with CPUFreq policies. In case of other devices the @cpus
43
+ * field is unused.
3644 */
3745 struct em_perf_domain {
38
- struct em_cap_state *table;
39
- int nr_cap_states;
40
- unsigned long cpus[0];
46
+ struct em_perf_state *table;
47
+ int nr_perf_states;
48
+ int milliwatts;
49
+ unsigned long cpus[];
4150 };
4251
43
-#define EM_CPU_MAX_POWER 0xFFFF
52
+#define em_span_cpus(em) (to_cpumask((em)->cpus))
53
+
54
+#ifdef CONFIG_ENERGY_MODEL
55
+#define EM_MAX_POWER 0xFFFF
56
+
57
+/*
58
+ * Increase resolution of energy estimation calculations for 64-bit
59
+ * architectures. The extra resolution improves decision made by EAS for the
60
+ * task placement when two Performance Domains might provide similar energy
61
+ * estimation values (w/o better resolution the values could be equal).
62
+ *
63
+ * We increase resolution only if we have enough bits to allow this increased
64
+ * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit
65
+ * are pretty high and the returns do not justify the increased costs.
66
+ */
67
+#ifdef CONFIG_64BIT
68
+#define em_scale_power(p) ((p) * 1000)
69
+#else
70
+#define em_scale_power(p) (p)
71
+#endif
4472
4573 struct em_data_callback {
4674 /**
47
- * active_power() - Provide power at the next capacity state of a CPU
48
- * @power : Active power at the capacity state in mW (modified)
49
- * @freq : Frequency at the capacity state in kHz (modified)
50
- * @cpu : CPU for which we do this operation
75
+ * active_power() - Provide power at the next performance state of
76
+ * a device
77
+ * @power : Active power at the performance state in mW
78
+ * (modified)
79
+ * @freq : Frequency at the performance state in kHz
80
+ * (modified)
81
+ * @dev : Device for which we do this operation (can be a CPU)
5182 *
52
- * active_power() must find the lowest capacity state of 'cpu' above
83
+ * active_power() must find the lowest performance state of 'dev' above
5384 * 'freq' and update 'power' and 'freq' to the matching active power
5485 * and frequency.
5586 *
56
- * The power is the one of a single CPU in the domain, expressed in
57
- * milli-watts. It is expected to fit in the [0, EM_CPU_MAX_POWER]
58
- * range.
87
+ * In case of CPUs, the power is the one of a single CPU in the domain,
88
+ * expressed in milli-watts. It is expected to fit in the
89
+ * [0, EM_MAX_POWER] range.
5990 *
6091 * Return 0 on success.
6192 */
62
- int (*active_power)(unsigned long *power, unsigned long *freq, int cpu);
93
+ int (*active_power)(unsigned long *power, unsigned long *freq,
94
+ struct device *dev);
6395 };
6496 #define EM_DATA_CB(_active_power_cb) { .active_power = &_active_power_cb }
6597
6698 struct em_perf_domain *em_cpu_get(int cpu);
67
-int em_register_perf_domain(cpumask_t *span, unsigned int nr_states,
68
- struct em_data_callback *cb);
99
+struct em_perf_domain *em_pd_get(struct device *dev);
100
+int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
101
+ struct em_data_callback *cb, cpumask_t *span,
102
+ bool milliwatts);
103
+void em_dev_unregister_perf_domain(struct device *dev);
69104
70105 /**
71
- * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. domain
106
+ * em_cpu_energy() - Estimates the energy consumed by the CPUs of a
107
+ performance domain
72108 * @pd : performance domain for which energy has to be estimated
73109 * @max_util : highest utilization among CPUs of the domain
74110 * @sum_util : sum of the utilization of all CPUs in the domain
75111 *
112
+ * This function must be used only for CPU devices. There is no validation,
113
+ * i.e. if the EM is a CPU type and has cpumask allocated. It is called from
114
+ * the scheduler code quite frequently and that is why there is not checks.
115
+ *
76116 * Return: the sum of the energy consumed by the CPUs of the domain assuming
77117 * a capacity state satisfying the max utilization of the domain.
78118 */
79
-static inline unsigned long em_pd_energy(struct em_perf_domain *pd,
119
+static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
80120 unsigned long max_util, unsigned long sum_util)
81121 {
82122 unsigned long freq, scale_cpu;
83
- struct em_cap_state *cs;
123
+ struct em_perf_state *ps;
84124 int i, cpu;
85125
86
- /*
87
- * In order to predict the capacity state, map the utilization of the
88
- * most utilized CPU of the performance domain to a requested frequency,
89
- * like schedutil.
90
- */
91
- cpu = cpumask_first(to_cpumask(pd->cpus));
92
- scale_cpu = arch_scale_cpu_capacity(NULL, cpu);
93
- cs = &pd->table[pd->nr_cap_states - 1];
94
- freq = map_util_freq(max_util, cs->frequency, scale_cpu);
126
+ if (!sum_util)
127
+ return 0;
95128
96129 /*
97
- * Find the lowest capacity state of the Energy Model above the
130
+ * In order to predict the performance state, map the utilization of
131
+ * the most utilized CPU of the performance domain to a requested
132
+ * frequency, like schedutil.
133
+ */
134
+ cpu = cpumask_first(to_cpumask(pd->cpus));
135
+ scale_cpu = arch_scale_cpu_capacity(cpu);
136
+ ps = &pd->table[pd->nr_perf_states - 1];
137
+ freq = map_util_freq(max_util, ps->frequency, scale_cpu);
138
+
139
+ /*
140
+ * Find the lowest performance state of the Energy Model above the
98141 * requested frequency.
99142 */
100
- for (i = 0; i < pd->nr_cap_states; i++) {
101
- cs = &pd->table[i];
102
- if (cs->frequency >= freq)
143
+ for (i = 0; i < pd->nr_perf_states; i++) {
144
+ ps = &pd->table[i];
145
+ if (ps->frequency >= freq)
103146 break;
104147 }
105148
106149 /*
107
- * The capacity of a CPU in the domain at that capacity state (cs)
150
+ * The capacity of a CPU in the domain at the performance state (ps)
108151 * can be computed as:
109152 *
110
- * cs->freq * scale_cpu
111
- * cs->cap = -------------------- (1)
153
+ * ps->freq * scale_cpu
154
+ * ps->cap = -------------------- (1)
112155 * cpu_max_freq
113156 *
114157 * So, ignoring the costs of idle states (which are not available in
115
- * the EM), the energy consumed by this CPU at that capacity state is
116
- * estimated as:
158
+ * the EM), the energy consumed by this CPU at that performance state
159
+ * is estimated as:
117160 *
118
- * cs->power * cpu_util
161
+ * ps->power * cpu_util
119162 * cpu_nrg = -------------------- (2)
120
- * cs->cap
163
+ * ps->cap
121164 *
122
- * since 'cpu_util / cs->cap' represents its percentage of busy time.
165
+ * since 'cpu_util / ps->cap' represents its percentage of busy time.
123166 *
124167 * NOTE: Although the result of this computation actually is in
125168 * units of power, it can be manipulated as an energy value
....@@ -129,56 +172,65 @@
129172 * By injecting (1) in (2), 'cpu_nrg' can be re-expressed as a product
130173 * of two terms:
131174 *
132
- * cs->power * cpu_max_freq cpu_util
175
+ * ps->power * cpu_max_freq cpu_util
133176 * cpu_nrg = ------------------------ * --------- (3)
134
- * cs->freq scale_cpu
177
+ * ps->freq scale_cpu
135178 *
136
- * The first term is static, and is stored in the em_cap_state struct
137
- * as 'cs->cost'.
179
+ * The first term is static, and is stored in the em_perf_state struct
180
+ * as 'ps->cost'.
138181 *
139182 * Since all CPUs of the domain have the same micro-architecture, they
140
- * share the same 'cs->cost', and the same CPU capacity. Hence, the
183
+ * share the same 'ps->cost', and the same CPU capacity. Hence, the
141184 * total energy of the domain (which is the simple sum of the energy of
142185 * all of its CPUs) can be factorized as:
143186 *
144
- * cs->cost * \Sum cpu_util
187
+ * ps->cost * \Sum cpu_util
145188 * pd_nrg = ------------------------ (4)
146189 * scale_cpu
147190 */
148
- return cs->cost * sum_util / scale_cpu;
191
+ return ps->cost * sum_util / scale_cpu;
149192 }
150193
151194 /**
152
- * em_pd_nr_cap_states() - Get the number of capacity states of a perf. domain
195
+ * em_pd_nr_perf_states() - Get the number of performance states of a perf.
196
+ * domain
153197 * @pd : performance domain for which this must be done
154198 *
155
- * Return: the number of capacity states in the performance domain table
199
+ * Return: the number of performance states in the performance domain table
156200 */
157
-static inline int em_pd_nr_cap_states(struct em_perf_domain *pd)
201
+static inline int em_pd_nr_perf_states(struct em_perf_domain *pd)
158202 {
159
- return pd->nr_cap_states;
203
+ return pd->nr_perf_states;
160204 }
161205
162206 #else
163
-struct em_perf_domain {};
164207 struct em_data_callback {};
165208 #define EM_DATA_CB(_active_power_cb) { }
166209
167
-static inline int em_register_perf_domain(cpumask_t *span,
168
- unsigned int nr_states, struct em_data_callback *cb)
210
+static inline
211
+int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
212
+ struct em_data_callback *cb, cpumask_t *span,
213
+ bool milliwatts)
169214 {
170215 return -EINVAL;
216
+}
217
+static inline void em_dev_unregister_perf_domain(struct device *dev)
218
+{
171219 }
172220 static inline struct em_perf_domain *em_cpu_get(int cpu)
173221 {
174222 return NULL;
175223 }
176
-static inline unsigned long em_pd_energy(struct em_perf_domain *pd,
224
+static inline struct em_perf_domain *em_pd_get(struct device *dev)
225
+{
226
+ return NULL;
227
+}
228
+static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
177229 unsigned long max_util, unsigned long sum_util)
178230 {
179231 return 0;
180232 }
181
-static inline int em_pd_nr_cap_states(struct em_perf_domain *pd)
233
+static inline int em_pd_nr_perf_states(struct em_perf_domain *pd)
182234 {
183235 return 0;
184236 }