233 строки
7.5 KiB
C
233 строки
7.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_ENERGY_MODEL_H
|
|
#define _LINUX_ENERGY_MODEL_H
|
|
#include <linux/cpumask.h>
|
|
#include <linux/device.h>
|
|
#include <linux/jump_label.h>
|
|
#include <linux/kobject.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <linux/sched/cpufreq.h>
|
|
#include <linux/sched/topology.h>
|
|
#include <linux/types.h>
|
|
|
|
/**
|
|
* em_perf_state - Performance state of a performance domain
|
|
* @frequency: The frequency in KHz, for consistency with CPUFreq
|
|
* @power: The power consumed at this level (by 1 CPU or by a registered
|
|
* device). It can be a total power: static and dynamic.
|
|
* @cost: The cost coefficient associated with this level, used during
|
|
* energy calculation. Equal to: power * max_frequency / frequency
|
|
*/
|
|
struct em_perf_state {
|
|
unsigned long frequency;
|
|
unsigned long power;
|
|
unsigned long cost;
|
|
};
|
|
|
|
/**
|
|
* em_perf_domain - Performance domain
|
|
* @table: List of performance states, in ascending order
|
|
* @nr_perf_states: Number of performance states
|
|
* @milliwatts: Flag indicating the power values are in milli-Watts
|
|
* or some other scale.
|
|
* @cpus: Cpumask covering the CPUs of the domain. It's here
|
|
* for performance reasons to avoid potential cache
|
|
* misses during energy calculations in the scheduler
|
|
* and simplifies allocating/freeing that memory region.
|
|
*
|
|
* In case of CPU device, a "performance domain" represents a group of CPUs
|
|
* whose performance is scaled together. All CPUs of a performance domain
|
|
* must have the same micro-architecture. Performance domains often have
|
|
* a 1-to-1 mapping with CPUFreq policies. In case of other devices the @cpus
|
|
* field is unused.
|
|
*/
|
|
struct em_perf_domain {
|
|
struct em_perf_state *table;
|
|
int nr_perf_states;
|
|
int milliwatts;
|
|
unsigned long cpus[];
|
|
};
|
|
|
|
#define em_span_cpus(em) (to_cpumask((em)->cpus))
|
|
|
|
#ifdef CONFIG_ENERGY_MODEL
|
|
#define EM_MAX_POWER 0xFFFF
|
|
|
|
struct em_data_callback {
|
|
/**
|
|
* active_power() - Provide power at the next performance state of
|
|
* a device
|
|
* @power : Active power at the performance state
|
|
* (modified)
|
|
* @freq : Frequency at the performance state in kHz
|
|
* (modified)
|
|
* @dev : Device for which we do this operation (can be a CPU)
|
|
*
|
|
* active_power() must find the lowest performance state of 'dev' above
|
|
* 'freq' and update 'power' and 'freq' to the matching active power
|
|
* and frequency.
|
|
*
|
|
* In case of CPUs, the power is the one of a single CPU in the domain,
|
|
* expressed in milli-Watts or an abstract scale. It is expected to
|
|
* fit in the [0, EM_MAX_POWER] range.
|
|
*
|
|
* Return 0 on success.
|
|
*/
|
|
int (*active_power)(unsigned long *power, unsigned long *freq,
|
|
struct device *dev);
|
|
};
|
|
#define EM_DATA_CB(_active_power_cb) { .active_power = &_active_power_cb }
|
|
|
|
struct em_perf_domain *em_cpu_get(int cpu);
|
|
struct em_perf_domain *em_pd_get(struct device *dev);
|
|
int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
|
|
struct em_data_callback *cb, cpumask_t *span,
|
|
bool milliwatts);
|
|
void em_dev_unregister_perf_domain(struct device *dev);
|
|
|
|
/**
|
|
* em_cpu_energy() - Estimates the energy consumed by the CPUs of a
|
|
performance domain
|
|
* @pd : performance domain for which energy has to be estimated
|
|
* @max_util : highest utilization among CPUs of the domain
|
|
* @sum_util : sum of the utilization of all CPUs in the domain
|
|
* @allowed_cpu_cap : maximum allowed CPU capacity for the @pd, which
|
|
might reflect reduced frequency (due to thermal)
|
|
*
|
|
* This function must be used only for CPU devices. There is no validation,
|
|
* i.e. if the EM is a CPU type and has cpumask allocated. It is called from
|
|
* the scheduler code quite frequently and that is why there is not checks.
|
|
*
|
|
* Return: the sum of the energy consumed by the CPUs of the domain assuming
|
|
* a capacity state satisfying the max utilization of the domain.
|
|
*/
|
|
static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
|
|
unsigned long max_util, unsigned long sum_util,
|
|
unsigned long allowed_cpu_cap)
|
|
{
|
|
unsigned long freq, scale_cpu;
|
|
struct em_perf_state *ps;
|
|
int i, cpu;
|
|
|
|
if (!sum_util)
|
|
return 0;
|
|
|
|
/*
|
|
* In order to predict the performance state, map the utilization of
|
|
* the most utilized CPU of the performance domain to a requested
|
|
* frequency, like schedutil. Take also into account that the real
|
|
* frequency might be set lower (due to thermal capping). Thus, clamp
|
|
* max utilization to the allowed CPU capacity before calculating
|
|
* effective frequency.
|
|
*/
|
|
cpu = cpumask_first(to_cpumask(pd->cpus));
|
|
scale_cpu = arch_scale_cpu_capacity(cpu);
|
|
ps = &pd->table[pd->nr_perf_states - 1];
|
|
|
|
max_util = map_util_perf(max_util);
|
|
max_util = min(max_util, allowed_cpu_cap);
|
|
freq = map_util_freq(max_util, ps->frequency, scale_cpu);
|
|
|
|
/*
|
|
* Find the lowest performance state of the Energy Model above the
|
|
* requested frequency.
|
|
*/
|
|
for (i = 0; i < pd->nr_perf_states; i++) {
|
|
ps = &pd->table[i];
|
|
if (ps->frequency >= freq)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* The capacity of a CPU in the domain at the performance state (ps)
|
|
* can be computed as:
|
|
*
|
|
* ps->freq * scale_cpu
|
|
* ps->cap = -------------------- (1)
|
|
* cpu_max_freq
|
|
*
|
|
* So, ignoring the costs of idle states (which are not available in
|
|
* the EM), the energy consumed by this CPU at that performance state
|
|
* is estimated as:
|
|
*
|
|
* ps->power * cpu_util
|
|
* cpu_nrg = -------------------- (2)
|
|
* ps->cap
|
|
*
|
|
* since 'cpu_util / ps->cap' represents its percentage of busy time.
|
|
*
|
|
* NOTE: Although the result of this computation actually is in
|
|
* units of power, it can be manipulated as an energy value
|
|
* over a scheduling period, since it is assumed to be
|
|
* constant during that interval.
|
|
*
|
|
* By injecting (1) in (2), 'cpu_nrg' can be re-expressed as a product
|
|
* of two terms:
|
|
*
|
|
* ps->power * cpu_max_freq cpu_util
|
|
* cpu_nrg = ------------------------ * --------- (3)
|
|
* ps->freq scale_cpu
|
|
*
|
|
* The first term is static, and is stored in the em_perf_state struct
|
|
* as 'ps->cost'.
|
|
*
|
|
* Since all CPUs of the domain have the same micro-architecture, they
|
|
* share the same 'ps->cost', and the same CPU capacity. Hence, the
|
|
* total energy of the domain (which is the simple sum of the energy of
|
|
* all of its CPUs) can be factorized as:
|
|
*
|
|
* ps->cost * \Sum cpu_util
|
|
* pd_nrg = ------------------------ (4)
|
|
* scale_cpu
|
|
*/
|
|
return ps->cost * sum_util / scale_cpu;
|
|
}
|
|
|
|
/**
|
|
* em_pd_nr_perf_states() - Get the number of performance states of a perf.
|
|
* domain
|
|
* @pd : performance domain for which this must be done
|
|
*
|
|
* Return: the number of performance states in the performance domain table
|
|
*/
|
|
static inline int em_pd_nr_perf_states(struct em_perf_domain *pd)
|
|
{
|
|
return pd->nr_perf_states;
|
|
}
|
|
|
|
#else
|
|
struct em_data_callback {};
|
|
#define EM_DATA_CB(_active_power_cb) { }
|
|
|
|
static inline
|
|
int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
|
|
struct em_data_callback *cb, cpumask_t *span,
|
|
bool milliwatts)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
static inline void em_dev_unregister_perf_domain(struct device *dev)
|
|
{
|
|
}
|
|
static inline struct em_perf_domain *em_cpu_get(int cpu)
|
|
{
|
|
return NULL;
|
|
}
|
|
static inline struct em_perf_domain *em_pd_get(struct device *dev)
|
|
{
|
|
return NULL;
|
|
}
|
|
static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
|
|
unsigned long max_util, unsigned long sum_util,
|
|
unsigned long allowed_cpu_cap)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int em_pd_nr_perf_states(struct em_perf_domain *pd)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#endif
|