diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 7aa3dcad21758c755ef0c76595ed2459ec94d671..6f23ebb395f14c8fe04225bad75176ca262d197f 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2277,6 +2277,7 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy,
ret = cpufreq_start_governor(policy);
if (!ret) {
pr_debug("cpufreq: governor change\n");
+ sched_cpufreq_governor_change(policy, old_gov);
return 0;
}
cpufreq_exit_governor(policy);
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 882a9b9e34bc2c0dc8ad00eaa58d23c784b6c2f5..c86d6d8bdfed2079a161bea6946ce3f6d47d8ac8 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -950,6 +950,14 @@ static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
}
#endif
+#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
+void sched_cpufreq_governor_change(struct cpufreq_policy *policy,
+ struct cpufreq_governor *old_gov);
+#else
+static inline void sched_cpufreq_governor_change(struct cpufreq_policy *policy,
+ struct cpufreq_governor *old_gov) { }
+#endif
+
extern void arch_freq_prepare_all(void);
extern unsigned int arch_freq_get_on_cpu(int cpu);
diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
new file mode 100644
index 0000000000000000000000000000000000000000..aa027f7bcb3e848e947340562a0e04f7763009f4
--- /dev/null
+++ b/include/linux/energy_model.h
@@ -0,0 +1,187 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_ENERGY_MODEL_H
+#define _LINUX_ENERGY_MODEL_H
+#include <linux/cpumask.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>
+
+#ifdef CONFIG_ENERGY_MODEL
+/**
+ * em_cap_state - Capacity state of a performance domain
+ * @frequency: The CPU frequency in KHz, for consistency with CPUFreq
+ * @power: The power consumed by 1 CPU at this level, in milli-watts
+ * @cost: The cost coefficient associated with this level, used during
+ * energy calculation. Equal to: power * max_frequency / frequency
+ */
+struct em_cap_state {
+ unsigned long frequency;
+ unsigned long power;
+ unsigned long cost;
+};
+
+/**
+ * em_perf_domain - Performance domain
+ * @table: List of capacity states, in ascending order
+ * @nr_cap_states: Number of capacity states
+ * @cpus: Cpumask covering the CPUs of the domain
+ *
+ * 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.
+ */
+struct em_perf_domain {
+ struct em_cap_state *table;
+ int nr_cap_states;
+ unsigned long cpus[0];
+};
+
+#define EM_CPU_MAX_POWER 0xFFFF
+
+struct em_data_callback {
+ /**
+ * active_power() - Provide power at the next capacity state of a CPU
+ * @power : Active power at the capacity state in mW (modified)
+ * @freq : Frequency at the capacity state in kHz (modified)
+ * @cpu : CPU for which we do this operation
+ *
+ * active_power() must find the lowest capacity state of 'cpu' above
+ * 'freq' and update 'power' and 'freq' to the matching active power
+ * and frequency.
+ *
+ * The power is the one of a single CPU in the domain, expressed in
+ * milli-watts. It is expected to fit in the [0, EM_CPU_MAX_POWER]
+ * range.
+ *
+ * Return 0 on success.
+ */
+ int (*active_power)(unsigned long *power, unsigned long *freq, int cpu);
+};
+#define EM_DATA_CB(_active_power_cb) { .active_power = &_active_power_cb }
+
+struct em_perf_domain *em_cpu_get(int cpu);
+int em_register_perf_domain(cpumask_t *span, unsigned int nr_states,
+ struct em_data_callback *cb);
+
+/**
+ * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. 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
+ *
+ * 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_pd_energy(struct em_perf_domain *pd,
+ unsigned long max_util, unsigned long sum_util)
+{
+ unsigned long freq, scale_cpu;
+ struct em_cap_state *cs;
+ int i, cpu;
+
+ /*
+ * In order to predict the capacity state, map the utilization of the
+ * most utilized CPU of the performance domain to a requested frequency,
+ * like schedutil.
+ */
+ cpu = cpumask_first(to_cpumask(pd->cpus));
+ scale_cpu = arch_scale_cpu_capacity(NULL, cpu);
+ cs = &pd->table[pd->nr_cap_states - 1];
+ freq = map_util_freq(max_util, cs->frequency, scale_cpu);
+
+ /*
+ * Find the lowest capacity state of the Energy Model above the
+ * requested frequency.
+ */
+ for (i = 0; i < pd->nr_cap_states; i++) {
+ cs = &pd->table[i];
+ if (cs->frequency >= freq)
+ break;
+ }
+
+ /*
+ * The capacity of a CPU in the domain at that capacity state (cs)
+ * can be computed as:
+ *
+ * cs->freq * scale_cpu
+ * cs->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 capacity state is
+ * estimated as:
+ *
+ * cs->power * cpu_util
+ * cpu_nrg = -------------------- (2)
+ * cs->cap
+ *
+ * since 'cpu_util / cs->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:
+ *
+ * cs->power * cpu_max_freq cpu_util
+ * cpu_nrg = ------------------------ * --------- (3)
+ * cs->freq scale_cpu
+ *
+ * The first term is static, and is stored in the em_cap_state struct
+ * as 'cs->cost'.
+ *
+ * Since all CPUs of the domain have the same micro-architecture, they
+ * share the same 'cs->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:
+ *
+ * cs->cost * \Sum cpu_util
+ * pd_nrg = ------------------------ (4)
+ * scale_cpu
+ */
+ return cs->cost * sum_util / scale_cpu;
+}
+
+/**
+ * em_pd_nr_cap_states() - Get the number of capacity states of a perf. domain
+ * @pd : performance domain for which this must be done
+ *
+ * Return: the number of capacity states in the performance domain table
+ */
+static inline int em_pd_nr_cap_states(struct em_perf_domain *pd)
+{
+ return pd->nr_cap_states;
+}
+
+#else
+struct em_perf_domain {};
+struct em_data_callback {};
+#define EM_DATA_CB(_active_power_cb) { }
+
+static inline int em_register_perf_domain(cpumask_t *span,
+ unsigned int nr_states, struct em_data_callback *cb)
+{
+ return -EINVAL;
+}
+static inline struct em_perf_domain *em_cpu_get(int cpu)
+{
+ return NULL;
+}
+static inline unsigned long em_pd_energy(struct em_perf_domain *pd,
+ unsigned long max_util, unsigned long sum_util)
+{
+ return 0;
+}
+static inline int em_pd_nr_cap_states(struct em_perf_domain *pd)
+{
+ return 0;
+}
+#endif
+
+#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4f1db3ef62a9032fb17b34bee4ded192fd9feb0d..89541d248893e2e04b3e1849956a43b8b4c9c12d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -176,7 +176,7 @@ struct task_group;
* TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
*
* However, with slightly different timing the wakeup TASK_RUNNING store can
- * also collide with the TASK_UNINTERRUPTIBLE store. Loosing that store is not
+ * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
* a problem either because that will result in one extra go around the loop
* and our @cond test will save the day.
*
@@ -515,7 +515,7 @@ struct sched_dl_entity {
/*
* Actual scheduling parameters. Initialized with the values above,
- * they are continously updated during task execution. Note that
+ * they are continuously updated during task execution. Note that
* the remaining runtime could be < 0 in case we are in overrun.
*/
s64 runtime; /* Remaining runtime for this instance */
diff --git a/include/linux/sched/cpufreq.h b/include/linux/sched/cpufreq.h
index 59667444669fc0f10de065cefe770f11fff1c1b6..afa940cd50dc5355bed0815c0d7a0c20a548fb98 100644
--- a/include/linux/sched/cpufreq.h
+++ b/include/linux/sched/cpufreq.h
@@ -20,6 +20,12 @@ void cpufreq_add_update_util_hook(int cpu, struct update_util_data *data,
void (*func)(struct update_util_data *data, u64 time,
unsigned int flags));
void cpufreq_remove_update_util_hook(int cpu);
+
+static inline unsigned long map_util_freq(unsigned long util,
+ unsigned long freq, unsigned long cap)
+{
+ return (freq + (freq >> 2)) * util / cap;
+}
#endif /* CONFIG_CPU_FREQ */
#endif /* _LINUX_SCHED_CPUFREQ_H */
diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index 4a6582c27dea7bb3f15338b97b67869a9b4b05d0..b0fb1446fe04d809ab9fa0763e7d7b27ff2a2c6c 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h
@@ -16,7 +16,7 @@ enum hk_flags {
};
#ifdef CONFIG_CPU_ISOLATION
-DECLARE_STATIC_KEY_FALSE(housekeeping_overriden);
+DECLARE_STATIC_KEY_FALSE(housekeeping_overridden);
extern int housekeeping_any_cpu(enum hk_flags flags);
extern const struct cpumask *housekeeping_cpumask(enum hk_flags flags);
extern void housekeeping_affine(struct task_struct *t, enum hk_flags flags);
@@ -43,7 +43,7 @@ static inline void housekeeping_init(void) { }
static inline bool housekeeping_cpu(int cpu, enum hk_flags flags)
{
#ifdef CONFIG_CPU_ISOLATION
- if (static_branch_unlikely(&housekeeping_overriden))
+ if (static_branch_unlikely(&housekeeping_overridden))
return housekeeping_test_cpu(cpu, flags);
#endif
return true;
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index aebb370a000624f0258a7c0a2465a4ea2d3e6acf..3bfa6a0cbba4edc7bf0a9e33798e227526633bfa 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -153,7 +153,7 @@ static inline gfp_t current_gfp_context(gfp_t flags)
{
/*
* NOIO implies both NOIO and NOFS and it is a weaker context
- * so always make sure it makes precendence
+ * so always make sure it makes precedence
*/
if (unlikely(current->flags & PF_MEMALLOC_NOIO))
flags &= ~(__GFP_IO | __GFP_FS);
diff --git a/include/linux/sched/stat.h b/include/linux/sched/stat.h
index f30954cc059dfd8e60870c1b4328949272947bf3..568286411b43ab5b48378eea1bbb0441bb8a520f 100644
--- a/include/linux/sched/stat.h
+++ b/include/linux/sched/stat.h
@@ -8,7 +8,7 @@
* Various counters maintained by the scheduler and fork(),
* exposed via /proc, sys.c or used by drivers via these APIs.
*
- * ( Note that all these values are aquired without locking,
+ * ( Note that all these values are acquired without locking,
* so they can only be relied on in narrow circumstances. )
*/
diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
index 6b9976180c1ebab037c31032999fbe59a991893b..c31d3a47a47cc57478a25c0738cb7224a158c30e 100644
--- a/include/linux/sched/topology.h
+++ b/include/linux/sched/topology.h
@@ -89,7 +89,6 @@ struct sched_domain {
unsigned int newidle_idx;
unsigned int wake_idx;
unsigned int forkexec_idx;
- unsigned int smt_gain;
int nohz_idle; /* NOHZ IDLE status */
int flags; /* See SD_* */
@@ -202,6 +201,14 @@ extern void set_sched_topology(struct sched_domain_topology_level *tl);
# define SD_INIT_NAME(type)
#endif
+#ifndef arch_scale_cpu_capacity
+static __always_inline
+unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
+{
+ return SCHED_CAPACITY_SCALE;
+}
+#endif
+
#else /* CONFIG_SMP */
struct sched_domain_attr;
@@ -217,6 +224,14 @@ static inline bool cpus_share_cache(int this_cpu, int that_cpu)
return true;
}
+#ifndef arch_scale_cpu_capacity
+static __always_inline
+unsigned long arch_scale_cpu_capacity(void __always_unused *sd, int cpu)
+{
+ return SCHED_CAPACITY_SCALE;
+}
+#endif
+
#endif /* !CONFIG_SMP */
static inline int task_node(const struct task_struct *p)
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 3a6c2f87699e355e1772aa1320aa556e7201743b..f8fe57d1022e368b0ece751ba8c0140f66c965d8 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -298,3 +298,18 @@ config PM_GENERIC_DOMAINS_OF
config CPU_PM
bool
+
+config ENERGY_MODEL
+ bool "Energy Model for CPUs"
+ depends on SMP
+ depends on CPU_FREQ
+ default n
+ help
+ Several subsystems (thermal and/or the task scheduler for example)
+ can leverage information about the energy consumed by CPUs to make
+ smarter decisions. This config option enables the framework from
+ which subsystems can access the energy models.
+
+ The exact usage of the energy model is subsystem-dependent.
+
+ If in doubt, say N.
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index a3f79f0eef3675917752d09b4aff2d0d04ba776a..e7e47d9be1e56108e8f57bebad7760dcb173dbf1 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -15,3 +15,5 @@ obj-$(CONFIG_PM_AUTOSLEEP) += autosleep.o
obj-$(CONFIG_PM_WAKELOCKS) += wakelock.o
obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o
+
+obj-$(CONFIG_ENERGY_MODEL) += energy_model.o
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
new file mode 100644
index 0000000000000000000000000000000000000000..d9dc2c38764a3c3100f3708ce5b39ddfab072a91
--- /dev/null
+++ b/kernel/power/energy_model.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Energy Model of CPUs
+ *
+ * Copyright (c) 2018, Arm ltd.
+ * Written by: Quentin Perret, Arm ltd.
+ */
+
+#define pr_fmt(fmt) "energy_model: " fmt
+
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/energy_model.h>
+#include <linux/sched/topology.h>
+#include <linux/slab.h>
+
+/* Mapping of each CPU to the performance domain to which it belongs. */
+static DEFINE_PER_CPU(struct em_perf_domain *, em_data);
+
+/*
+ * Mutex serializing the registrations of performance domains and letting
+ * callbacks defined by drivers sleep.
+ */
+static DEFINE_MUTEX(em_pd_mutex);
+
+static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states,
+ struct em_data_callback *cb)
+{
+ unsigned long opp_eff, prev_opp_eff = ULONG_MAX;
+ unsigned long power, freq, prev_freq = 0;
+ int i, ret, cpu = cpumask_first(span);
+ struct em_cap_state *table;
+ struct em_perf_domain *pd;
+ u64 fmax;
+
+ if (!cb->active_power)
+ return NULL;
+
+ pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL);
+ if (!pd)
+ return NULL;
+
+ table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL);
+ if (!table)
+ goto free_pd;
+
+ /* Build the list of capacity states for this performance domain */
+ for (i = 0, freq = 0; i < nr_states; i++, freq++) {
+ /*
+ * active_power() is a driver callback which ceils 'freq' to
+ * lowest capacity state of 'cpu' above 'freq' and updates
+ * 'power' and 'freq' accordingly.
+ */
+ ret = cb->active_power(&power, &freq, cpu);
+ if (ret) {
+ pr_err("pd%d: invalid cap. state: %d\n", cpu, ret);
+ goto free_cs_table;
+ }
+
+ /*
+ * We expect the driver callback to increase the frequency for
+ * higher capacity states.
+ */
+ if (freq <= prev_freq) {
+ pr_err("pd%d: non-increasing freq: %lu\n", cpu, freq);
+ goto free_cs_table;
+ }
+
+ /*
+ * The power returned by active_state() is expected to be
+ * positive, in milli-watts and to fit into 16 bits.
+ */
+ if (!power || power > EM_CPU_MAX_POWER) {
+ pr_err("pd%d: invalid power: %lu\n", cpu, power);
+ goto free_cs_table;
+ }
+
+ table[i].power = power;
+ table[i].frequency = prev_freq = freq;
+
+ /*
+ * The hertz/watts efficiency ratio should decrease as the
+ * frequency grows on sane platforms. But this isn't always
+ * true in practice so warn the user if a higher OPP is more
+ * power efficient than a lower one.
+ */
+ opp_eff = freq / power;
+ if (opp_eff >= prev_opp_eff)
+ pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_cap_state %d >= em_cap_state%d\n",
+ cpu, i, i - 1);
+ prev_opp_eff = opp_eff;
+ }
+
+ /* Compute the cost of each capacity_state. */
+ fmax = (u64) table[nr_states - 1].frequency;
+ for (i = 0; i < nr_states; i++) {
+ table[i].cost = div64_u64(fmax * table[i].power,
+ table[i].frequency);
+ }
+
+ pd->table = table;
+ pd->nr_cap_states = nr_states;
+ cpumask_copy(to_cpumask(pd->cpus), span);
+
+ return pd;
+
+free_cs_table:
+ kfree(table);
+free_pd:
+ kfree(pd);
+
+ return NULL;
+}
+
+/**
+ * em_cpu_get() - Return the performance domain for a CPU
+ * @cpu : CPU to find the performance domain for
+ *
+ * Return: the performance domain to which 'cpu' belongs, or NULL if it doesn't
+ * exist.
+ */
+struct em_perf_domain *em_cpu_get(int cpu)
+{
+ return READ_ONCE(per_cpu(em_data, cpu));
+}
+EXPORT_SYMBOL_GPL(em_cpu_get);
+
+/**
+ * em_register_perf_domain() - Register the Energy Model of a performance domain
+ * @span : Mask of CPUs in the performance domain
+ * @nr_states : Number of capacity states to register
+ * @cb : Callback functions providing the data of the Energy Model
+ *
+ * Create Energy Model tables for a performance domain using the callbacks
+ * defined in cb.
+ *
+ * If multiple clients register the same performance domain, all but the first
+ * registration will be ignored.
+ *
+ * Return 0 on success
+ */
+int em_register_perf_domain(cpumask_t *span, unsigned int nr_states,
+ struct em_data_callback *cb)
+{
+ unsigned long cap, prev_cap = 0;
+ struct em_perf_domain *pd;
+ int cpu, ret = 0;
+
+ if (!span || !nr_states || !cb)
+ return -EINVAL;
+
+ /*
+ * Use a mutex to serialize the registration of performance domains and
+ * let the driver-defined callback functions sleep.
+ */
+ mutex_lock(&em_pd_mutex);
+
+ for_each_cpu(cpu, span) {
+ /* Make sure we don't register again an existing domain. */
+ if (READ_ONCE(per_cpu(em_data, cpu))) {
+ ret = -EEXIST;
+ goto unlock;
+ }
+
+ /*
+ * All CPUs of a domain must have the same micro-architecture
+ * since they all share the same table.
+ */
+ cap = arch_scale_cpu_capacity(NULL, cpu);
+ if (prev_cap && prev_cap != cap) {
+ pr_err("CPUs of %*pbl must have the same capacity\n",
+ cpumask_pr_args(span));
+ ret = -EINVAL;
+ goto unlock;
+ }
+ prev_cap = cap;
+ }
+
+ /* Create the performance domain and add it to the Energy Model. */
+ pd = em_create_pd(span, nr_states, cb);
+ if (!pd) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ for_each_cpu(cpu, span) {
+ /*
+ * The per-cpu array can be read concurrently from em_cpu_get().
+ * The barrier enforces the ordering needed to make sure readers
+ * can only access well formed em_perf_domain structs.
+ */
+ smp_store_release(per_cpu_ptr(&em_data, cpu), pd);
+ }
+
+ pr_debug("Created perf domain %*pbl\n", cpumask_pr_args(span));
+unlock:
+ mutex_unlock(&em_pd_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(em_register_perf_domain);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a5b7f1c9f24f1e6c8765221cab2757f1d59d3ddd..f6692017337032f4cc69f684d1a5039780b9fd34 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -697,7 +697,7 @@ static void set_load_weight(struct task_struct *p, bool update_load)
/*
* SCHED_IDLE tasks get minimal weight:
*/
- if (idle_policy(p->policy)) {
+ if (task_has_idle_policy(p)) {
load->weight = scale_load(WEIGHT_IDLEPRIO);
load->inv_weight = WMULT_IDLEPRIO;
p->se.runnable_weight = load->weight;
@@ -2857,7 +2857,7 @@ unsigned long nr_running(void)
* preemption, thus the result might have a time-of-check-to-time-of-use
* race. The caller is responsible to use it correctly, for example:
*
- * - from a non-preemptable section (of course)
+ * - from a non-preemptible section (of course)
*
* - from a thread that is bound to a single CPU
*
@@ -4191,7 +4191,7 @@ static int __sched_setscheduler(struct task_struct *p,
* Treat SCHED_IDLE as nice 20. Only allow a switch to
* SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
*/
- if (idle_policy(p->policy) && !idle_policy(policy)) {
+ if (task_has_idle_policy(p) && !idle_policy(policy)) {
if (!can_nice(p, task_nice(p)))
return -EPERM;
}
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 626ddd4ffa4333723a405e639258c44d9dd55dd0..033ec7c45f13f37f52dd33466911993e111b7ac0 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -10,6 +10,7 @@
#include "sched.h"
+#include <linux/sched/cpufreq.h>
#include <trace/events/power.h>
struct sugov_tunables {
@@ -164,7 +165,7 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy,
unsigned int freq = arch_scale_freq_invariant() ?
policy->cpuinfo.max_freq : policy->cur;
- freq = (freq + (freq >> 2)) * util / max;
+ freq = map_util_freq(util, freq, max);
if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update)
return sg_policy->next_freq;
@@ -194,15 +195,13 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy,
* based on the task model parameters and gives the minimal utilization
* required to meet deadlines.
*/
-static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)
+unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs,
+ unsigned long max, enum schedutil_type type)
{
- struct rq *rq = cpu_rq(sg_cpu->cpu);
- unsigned long util, irq, max;
-
- sg_cpu->max = max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu);
- sg_cpu->bw_dl = cpu_bw_dl(rq);
+ unsigned long dl_util, util, irq;
+ struct rq *rq = cpu_rq(cpu);
- if (rt_rq_is_runnable(&rq->rt))
+ if (type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt))
return max;
/*
@@ -220,21 +219,30 @@ static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)
* utilization (PELT windows are synchronized) we can directly add them
* to obtain the CPU's actual utilization.
*/
- util = cpu_util_cfs(rq);
+ util = util_cfs;
util += cpu_util_rt(rq);
+ dl_util = cpu_util_dl(rq);
+
/*
- * We do not make cpu_util_dl() a permanent part of this sum because we
- * want to use cpu_bw_dl() later on, but we need to check if the
- * CFS+RT+DL sum is saturated (ie. no idle time) such that we select
- * f_max when there is no idle time.
+ * For frequency selection we do not make cpu_util_dl() a permanent part
+ * of this sum because we want to use cpu_bw_dl() later on, but we need
+ * to check if the CFS+RT+DL sum is saturated (ie. no idle time) such
+ * that we select f_max when there is no idle time.
*
* NOTE: numerical errors or stop class might cause us to not quite hit
* saturation when we should -- something for later.
*/
- if ((util + cpu_util_dl(rq)) >= max)
+ if (util + dl_util >= max)
return max;
+ /*
+ * OTOH, for energy computation we need the estimated running time, so
+ * include util_dl and ignore dl_bw.
+ */
+ if (type == ENERGY_UTIL)
+ util += dl_util;
+
/*
* There is still idle time; further improve the number by using the
* irq metric. Because IRQ/steal time is hidden from the task clock we
@@ -257,7 +265,22 @@ static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)
* bw_dl as requested freq. However, cpufreq is not yet ready for such
* an interface. So, we only do the latter for now.
*/
- return min(max, util + sg_cpu->bw_dl);
+ if (type == FREQUENCY_UTIL)
+ util += cpu_bw_dl(rq);
+
+ return min(max, util);
+}
+
+static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)
+{
+ struct rq *rq = cpu_rq(sg_cpu->cpu);
+ unsigned long util = cpu_util_cfs(rq);
+ unsigned long max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu);
+
+ sg_cpu->max = max;
+ sg_cpu->bw_dl = cpu_bw_dl(rq);
+
+ return schedutil_freq_util(sg_cpu->cpu, util, max, FREQUENCY_UTIL);
}
/**
@@ -598,7 +621,7 @@ static struct kobj_type sugov_tunables_ktype = {
/********************** cpufreq governor interface *********************/
-static struct cpufreq_governor schedutil_gov;
+struct cpufreq_governor schedutil_gov;
static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy)
{
@@ -857,7 +880,7 @@ static void sugov_limits(struct cpufreq_policy *policy)
sg_policy->need_freq_update = true;
}
-static struct cpufreq_governor schedutil_gov = {
+struct cpufreq_governor schedutil_gov = {
.name = "schedutil",
.owner = THIS_MODULE,
.dynamic_switching = true,
@@ -880,3 +903,36 @@ static int __init sugov_register(void)
return cpufreq_register_governor(&schedutil_gov);
}
fs_initcall(sugov_register);
+
+#ifdef CONFIG_ENERGY_MODEL
+extern bool sched_energy_update;
+extern struct mutex sched_energy_mutex;
+
+static void rebuild_sd_workfn(struct work_struct *work)
+{
+ mutex_lock(&sched_energy_mutex);
+ sched_energy_update = true;
+ rebuild_sched_domains();
+ sched_energy_update = false;
+ mutex_unlock(&sched_energy_mutex);
+}
+static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn);
+
+/*
+ * EAS shouldn't be attempted without sugov, so rebuild the sched_domains
+ * on governor changes to make sure the scheduler knows about it.
+ */
+void sched_cpufreq_governor_change(struct cpufreq_policy *policy,
+ struct cpufreq_governor *old_gov)
+{
+ if (old_gov == &schedutil_gov || policy->governor == &schedutil_gov) {
+ /*
+ * When called from the cpufreq_register_driver() path, the
+ * cpu_hotplug_lock is already held, so use a work item to
+ * avoid nested locking in rebuild_sched_domains().
+ */
+ schedule_work(&rebuild_sd_work);
+ }
+
+}
+#endif
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 0796f938c4f0df3988bd1afbb30e5df8ce549f5e..ba4a143bdcf313298e19dfab352d33d46b592a3e 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -525,7 +525,7 @@ void account_idle_ticks(unsigned long ticks)
/*
* Perform (stime * rtime) / total, but avoid multiplication overflow by
- * loosing precision when the numbers are big.
+ * losing precision when the numbers are big.
*/
static u64 scale_stime(u64 stime, u64 rtime, u64 total)
{
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 91e4202b0634569514659aa905fddf5b0ec6a6e7..fb8b7b5d745d69d72013ab7732dae6e83882e690 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -727,7 +727,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
* refill the runtime and set the deadline a period in the future,
* because keeping the current (absolute) deadline of the task would
* result in breaking guarantees promised to other tasks (refer to
- * Documentation/scheduler/sched-deadline.txt for more informations).
+ * Documentation/scheduler/sched-deadline.txt for more information).
*
* This function returns true if:
*
@@ -1695,6 +1695,14 @@ static void start_hrtick_dl(struct rq *rq, struct task_struct *p)
}
#endif
+static inline void set_next_task(struct rq *rq, struct task_struct *p)
+{
+ p->se.exec_start = rq_clock_task(rq);
+
+ /* You can't push away the running task */
+ dequeue_pushable_dl_task(rq, p);
+}
+
static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq,
struct dl_rq *dl_rq)
{
@@ -1750,10 +1758,8 @@ pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
BUG_ON(!dl_se);
p = dl_task_of(dl_se);
- p->se.exec_start = rq_clock_task(rq);
- /* Running task will never be pushed. */
- dequeue_pushable_dl_task(rq, p);
+ set_next_task(rq, p);
if (hrtick_enabled(rq))
start_hrtick_dl(rq, p);
@@ -1808,12 +1814,7 @@ static void task_fork_dl(struct task_struct *p)
static void set_curr_task_dl(struct rq *rq)
{
- struct task_struct *p = rq->curr;
-
- p->se.exec_start = rq_clock_task(rq);
-
- /* You can't push away the running task */
- dequeue_pushable_dl_task(rq, p);
+ set_next_task(rq, rq->curr);
}
#ifdef CONFIG_SMP
@@ -2041,10 +2042,8 @@ static int push_dl_task(struct rq *rq)
return 0;
retry:
- if (unlikely(next_task == rq->curr)) {
- WARN_ON(1);
+ if (WARN_ON(next_task == rq->curr))
return 0;
- }
/*
* If next_task preempts rq->curr, and rq->curr
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 6383aa6a60ca02b255077ac98e33589e0fddb3fe..02bd5f969b21a2690c4ab9c68415eaf13c58817d 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -974,7 +974,7 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
#endif
P(policy);
P(prio);
- if (p->policy == SCHED_DEADLINE) {
+ if (task_has_dl_policy(p)) {
P(dl.runtime);
P(dl.deadline);
}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index db514993565b2274b0b02466dd7ffc03b7e66140..1c1cfbf6ba0c99e026d5672c1d9879e483e189b0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -38,7 +38,7 @@
* (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds)
*/
unsigned int sysctl_sched_latency = 6000000ULL;
-unsigned int normalized_sysctl_sched_latency = 6000000ULL;
+static unsigned int normalized_sysctl_sched_latency = 6000000ULL;
/*
* The initial- and re-scaling of tunables is configurable
@@ -58,8 +58,8 @@ enum sched_tunable_scaling sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_L
*
* (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
-unsigned int sysctl_sched_min_granularity = 750000ULL;
-unsigned int normalized_sysctl_sched_min_granularity = 750000ULL;
+unsigned int sysctl_sched_min_granularity = 750000ULL;
+static unsigned int normalized_sysctl_sched_min_granularity = 750000ULL;
/*
* This value is kept at sysctl_sched_latency/sysctl_sched_min_granularity
@@ -81,8 +81,8 @@ unsigned int sysctl_sched_child_runs_first __read_mostly;
*
* (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
-unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
-unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
+unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
+static unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
@@ -116,7 +116,7 @@ unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL;
*
* (default: ~20%)
*/
-unsigned int capacity_margin = 1280;
+static unsigned int capacity_margin = 1280;
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
@@ -703,9 +703,9 @@ void init_entity_runnable_average(struct sched_entity *se)
memset(sa, 0, sizeof(*sa));
/*
- * Tasks are intialized with full load to be seen as heavy tasks until
+ * Tasks are initialized with full load to be seen as heavy tasks until
* they get a chance to stabilize to their real load level.
- * Group entities are intialized with zero load to reflect the fact that
+ * Group entities are initialized with zero load to reflect the fact that
* nothing has been attached to the task group yet.
*/
if (entity_is_task(se))
@@ -2734,6 +2734,17 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
WRITE_ONCE(*ptr, res); \
} while (0)
+/*
+ * Remove and clamp on negative, from a local variable.
+ *
+ * A variant of sub_positive(), which does not use explicit load-store
+ * and is thus optimized for local variable updates.
+ */
+#define lsub_positive(_ptr, _val) do { \
+ typeof(_ptr) ptr = (_ptr); \
+ *ptr -= min_t(typeof(*ptr), *ptr, _val); \
+} while (0)
+
#ifdef CONFIG_SMP
static inline void
enqueue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -3604,7 +3615,7 @@ static inline unsigned long _task_util_est(struct task_struct *p)
{
struct util_est ue = READ_ONCE(p->se.avg.util_est);
- return max(ue.ewma, ue.enqueued);
+ return (max(ue.ewma, ue.enqueued) | UTIL_AVG_UNCHANGED);
}
static inline unsigned long task_util_est(struct task_struct *p)
@@ -3622,7 +3633,7 @@ static inline void util_est_enqueue(struct cfs_rq *cfs_rq,
/* Update root cfs_rq's estimated utilization */
enqueued = cfs_rq->avg.util_est.enqueued;
- enqueued += (_task_util_est(p) | UTIL_AVG_UNCHANGED);
+ enqueued += _task_util_est(p);
WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued);
}
@@ -3650,8 +3661,7 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
/* Update root cfs_rq's estimated utilization */
ue.enqueued = cfs_rq->avg.util_est.enqueued;
- ue.enqueued -= min_t(unsigned int, ue.enqueued,
- (_task_util_est(p) | UTIL_AVG_UNCHANGED));
+ ue.enqueued -= min_t(unsigned int, ue.enqueued, _task_util_est(p));
WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued);
/*
@@ -3966,8 +3976,8 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
/*
* When dequeuing a sched_entity, we must:
* - Update loads to have both entity and cfs_rq synced with now.
- * - Substract its load from the cfs_rq->runnable_avg.
- * - Substract its previous weight from cfs_rq->load.weight.
+ * - Subtract its load from the cfs_rq->runnable_avg.
+ * - Subtract its previous weight from cfs_rq->load.weight.
* - For group entity, update its weight to reflect the new share
* of its group cfs_rq.
*/
@@ -4640,7 +4650,7 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
cfs_b->distribute_running = 0;
throttled = !list_empty(&cfs_b->throttled_cfs_rq);
- cfs_b->runtime -= min(runtime, cfs_b->runtime);
+ lsub_positive(&cfs_b->runtime, runtime);
}
/*
@@ -4774,7 +4784,7 @@ static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
raw_spin_lock(&cfs_b->lock);
if (expires == cfs_b->runtime_expires)
- cfs_b->runtime -= min(runtime, cfs_b->runtime);
+ lsub_positive(&cfs_b->runtime, runtime);
cfs_b->distribute_running = 0;
raw_spin_unlock(&cfs_b->lock);
}
@@ -5072,6 +5082,24 @@ static inline void hrtick_update(struct rq *rq)
}
#endif
+#ifdef CONFIG_SMP
+static inline unsigned long cpu_util(int cpu);
+static unsigned long capacity_of(int cpu);
+
+static inline bool cpu_overutilized(int cpu)
+{
+ return (capacity_of(cpu) * 1024) < (cpu_util(cpu) * capacity_margin);
+}
+
+static inline void update_overutilized_status(struct rq *rq)
+{
+ if (!READ_ONCE(rq->rd->overutilized) && cpu_overutilized(rq->cpu))
+ WRITE_ONCE(rq->rd->overutilized, SG_OVERUTILIZED);
+}
+#else
+static inline void update_overutilized_status(struct rq *rq) { }
+#endif
+
/*
* The enqueue_task method is called before nr_running is
* increased. Here we update the fair scheduling stats and
@@ -5129,8 +5157,26 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
update_cfs_group(se);
}
- if (!se)
+ if (!se) {
add_nr_running(rq, 1);
+ /*
+ * Since new tasks are assigned an initial util_avg equal to
+ * half of the spare capacity of their CPU, tiny tasks have the
+ * ability to cross the overutilized threshold, which will
+ * result in the load balancer ruining all the task placement
+ * done by EAS. As a way to mitigate that effect, do not account
+ * for the first enqueue operation of new tasks during the
+ * overutilized flag detection.
+ *
+ * A better way of solving this problem would be to wait for
+ * the PELT signals of tasks to converge before taking them
+ * into account, but that is not straightforward to implement,
+ * and the following generally works well enough in practice.
+ */
+ if (flags & ENQUEUE_WAKEUP)
+ update_overutilized_status(rq);
+
+ }
hrtick_update(rq);
}
@@ -6241,7 +6287,7 @@ static unsigned long cpu_util_without(int cpu, struct task_struct *p)
util = READ_ONCE(cfs_rq->avg.util_avg);
/* Discount task's util from CPU's util */
- util -= min_t(unsigned int, util, task_util(p));
+ lsub_positive(&util, task_util(p));
/*
* Covered cases:
@@ -6290,10 +6336,9 @@ static unsigned long cpu_util_without(int cpu, struct task_struct *p)
* properly fix the execl regression and it helps in further
* reducing the chances for the above race.
*/
- if (unlikely(task_on_rq_queued(p) || current == p)) {
- estimated -= min_t(unsigned int, estimated,
- (_task_util_est(p) | UTIL_AVG_UNCHANGED));
- }
+ if (unlikely(task_on_rq_queued(p) || current == p))
+ lsub_positive(&estimated, _task_util_est(p));
+
util = max(util, estimated);
}
@@ -6332,6 +6377,213 @@ static int wake_cap(struct task_struct *p, int cpu, int prev_cpu)
return !task_fits_capacity(p, min_cap);
}
+/*
+ * Predicts what cpu_util(@cpu) would return if @p was migrated (and enqueued)
+ * to @dst_cpu.
+ */
+static unsigned long cpu_util_next(int cpu, struct task_struct *p, int dst_cpu)
+{
+ struct cfs_rq *cfs_rq = &cpu_rq(cpu)->cfs;
+ unsigned long util_est, util = READ_ONCE(cfs_rq->avg.util_avg);
+
+ /*
+ * If @p migrates from @cpu to another, remove its contribution. Or,
+ * if @p migrates from another CPU to @cpu, add its contribution. In
+ * the other cases, @cpu is not impacted by the migration, so the
+ * util_avg should already be correct.
+ */
+ if (task_cpu(p) == cpu && dst_cpu != cpu)
+ sub_positive(&util, task_util(p));
+ else if (task_cpu(p) != cpu && dst_cpu == cpu)
+ util += task_util(p);
+
+ if (sched_feat(UTIL_EST)) {
+ util_est = READ_ONCE(cfs_rq->avg.util_est.enqueued);
+
+ /*
+ * During wake-up, the task isn't enqueued yet and doesn't
+ * appear in the cfs_rq->avg.util_est.enqueued of any rq,
+ * so just add it (if needed) to "simulate" what will be
+ * cpu_util() after the task has been enqueued.
+ */
+ if (dst_cpu == cpu)
+ util_est += _task_util_est(p);
+
+ util = max(util, util_est);
+ }
+
+ return min(util, capacity_orig_of(cpu));
+}
+
+/*
+ * compute_energy(): Estimates the energy that would be consumed if @p was
+ * migrated to @dst_cpu. compute_energy() predicts what will be the utilization
+ * landscape of the * CPUs after the task migration, and uses the Energy Model
+ * to compute what would be the energy if we decided to actually migrate that
+ * task.
+ */
+static long
+compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd)
+{
+ long util, max_util, sum_util, energy = 0;
+ int cpu;
+
+ for (; pd; pd = pd->next) {
+ max_util = sum_util = 0;
+ /*
+ * The capacity state of CPUs of the current rd can be driven by
+ * CPUs of another rd if they belong to the same performance
+ * domain. So, account for the utilization of these CPUs too
+ * by masking pd with cpu_online_mask instead of the rd span.
+ *
+ * If an entire performance domain is outside of the current rd,
+ * it will not appear in its pd list and will not be accounted
+ * by compute_energy().
+ */
+ for_each_cpu_and(cpu, perf_domain_span(pd), cpu_online_mask) {
+ util = cpu_util_next(cpu, p, dst_cpu);
+ util = schedutil_energy_util(cpu, util);
+ max_util = max(util, max_util);
+ sum_util += util;
+ }
+
+ energy += em_pd_energy(pd->em_pd, max_util, sum_util);
+ }
+
+ return energy;
+}
+
+/*
+ * find_energy_efficient_cpu(): Find most energy-efficient target CPU for the
+ * waking task. find_energy_efficient_cpu() looks for the CPU with maximum
+ * spare capacity in each performance domain and uses it as a potential
+ * candidate to execute the task. Then, it uses the Energy Model to figure
+ * out which of the CPU candidates is the most energy-efficient.
+ *
+ * The rationale for this heuristic is as follows. In a performance domain,
+ * all the most energy efficient CPU candidates (according to the Energy
+ * Model) are those for which we'll request a low frequency. When there are
+ * several CPUs for which the frequency request will be the same, we don't
+ * have enough data to break the tie between them, because the Energy Model
+ * only includes active power costs. With this model, if we assume that
+ * frequency requests follow utilization (e.g. using schedutil), the CPU with
+ * the maximum spare capacity in a performance domain is guaranteed to be among
+ * the best candidates of the performance domain.
+ *
+ * In practice, it could be preferable from an energy standpoint to pack
+ * small tasks on a CPU in order to let other CPUs go in deeper idle states,
+ * but that could also hurt our chances to go cluster idle, and we have no
+ * ways to tell with the current Energy Model if this is actually a good
+ * idea or not. So, find_energy_efficient_cpu() basically favors
+ * cluster-packing, and spreading inside a cluster. That should at least be
+ * a good thing for latency, and this is consistent with the idea that most
+ * of the energy savings of EAS come from the asymmetry of the system, and
+ * not so much from breaking the tie between identical CPUs. That's also the
+ * reason why EAS is enabled in the topology code only for systems where
+ * SD_ASYM_CPUCAPACITY is set.
+ *
+ * NOTE: Forkees are not accepted in the energy-aware wake-up path because
+ * they don't have any useful utilization data yet and it's not possible to
+ * forecast their impact on energy consumption. Consequently, they will be
+ * placed by find_idlest_cpu() on the least loaded CPU, which might turn out
+ * to be energy-inefficient in some use-cases. The alternative would be to
+ * bias new tasks towards specific types of CPUs first, or to try to infer
+ * their util_avg from the parent task, but those heuristics could hurt
+ * other use-cases too. So, until someone finds a better way to solve this,
+ * let's keep things simple by re-using the existing slow path.
+ */
+
+static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu)
+{
+ unsigned long prev_energy = ULONG_MAX, best_energy = ULONG_MAX;
+ struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
+ int cpu, best_energy_cpu = prev_cpu;
+ struct perf_domain *head, *pd;
+ unsigned long cpu_cap, util;
+ struct sched_domain *sd;
+
+ rcu_read_lock();
+ pd = rcu_dereference(rd->pd);
+ if (!pd || READ_ONCE(rd->overutilized))
+ goto fail;
+ head = pd;
+
+ /*
+ * Energy-aware wake-up happens on the lowest sched_domain starting
+ * from sd_asym_cpucapacity spanning over this_cpu and prev_cpu.
+ */
+ sd = rcu_dereference(*this_cpu_ptr(&sd_asym_cpucapacity));
+ while (sd && !cpumask_test_cpu(prev_cpu, sched_domain_span(sd)))
+ sd = sd->parent;
+ if (!sd)
+ goto fail;
+
+ sync_entity_load_avg(&p->se);
+ if (!task_util_est(p))
+ goto unlock;
+
+ for (; pd; pd = pd->next) {
+ unsigned long cur_energy, spare_cap, max_spare_cap = 0;
+ int max_spare_cap_cpu = -1;
+
+ for_each_cpu_and(cpu, perf_domain_span(pd), sched_domain_span(sd)) {
+ if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
+ continue;
+
+ /* Skip CPUs that will be overutilized. */
+ util = cpu_util_next(cpu, p, cpu);
+ cpu_cap = capacity_of(cpu);
+ if (cpu_cap * 1024 < util * capacity_margin)
+ continue;
+
+ /* Always use prev_cpu as a candidate. */
+ if (cpu == prev_cpu) {
+ prev_energy = compute_energy(p, prev_cpu, head);
+ best_energy = min(best_energy, prev_energy);
+ continue;
+ }
+
+ /*
+ * Find the CPU with the maximum spare capacity in
+ * the performance domain
+ */
+ spare_cap = cpu_cap - util;
+ if (spare_cap > max_spare_cap) {
+ max_spare_cap = spare_cap;
+ max_spare_cap_cpu = cpu;
+ }
+ }
+
+ /* Evaluate the energy impact of using this CPU. */
+ if (max_spare_cap_cpu >= 0) {
+ cur_energy = compute_energy(p, max_spare_cap_cpu, head);
+ if (cur_energy < best_energy) {
+ best_energy = cur_energy;
+ best_energy_cpu = max_spare_cap_cpu;
+ }
+ }
+ }
+unlock:
+ rcu_read_unlock();
+
+ /*
+ * Pick the best CPU if prev_cpu cannot be used, or if it saves at
+ * least 6% of the energy used by prev_cpu.
+ */
+ if (prev_energy == ULONG_MAX)
+ return best_energy_cpu;
+
+ if ((prev_energy - best_energy) > (prev_energy >> 4))
+ return best_energy_cpu;
+
+ return prev_cpu;
+
+fail:
+ rcu_read_unlock();
+
+ return -1;
+}
+
/*
* select_task_rq_fair: Select target runqueue for the waking task in domains
* that have the 'sd_flag' flag set. In practice, this is SD_BALANCE_WAKE,
@@ -6355,8 +6607,16 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
if (sd_flag & SD_BALANCE_WAKE) {
record_wakee(p);
- want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu)
- && cpumask_test_cpu(cpu, &p->cpus_allowed);
+
+ if (static_branch_unlikely(&sched_energy_present)) {
+ new_cpu = find_energy_efficient_cpu(p, prev_cpu);
+ if (new_cpu >= 0)
+ return new_cpu;
+ new_cpu = prev_cpu;
+ }
+
+ want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu) &&
+ cpumask_test_cpu(cpu, &p->cpus_allowed);
}
rcu_read_lock();
@@ -6520,7 +6780,7 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
static void set_last_buddy(struct sched_entity *se)
{
- if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
+ if (entity_is_task(se) && unlikely(task_has_idle_policy(task_of(se))))
return;
for_each_sched_entity(se) {
@@ -6532,7 +6792,7 @@ static void set_last_buddy(struct sched_entity *se)
static void set_next_buddy(struct sched_entity *se)
{
- if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
+ if (entity_is_task(se) && unlikely(task_has_idle_policy(task_of(se))))
return;
for_each_sched_entity(se) {
@@ -6590,8 +6850,8 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
return;
/* Idle tasks are by definition preempted by non-idle tasks. */
- if (unlikely(curr->policy == SCHED_IDLE) &&
- likely(p->policy != SCHED_IDLE))
+ if (unlikely(task_has_idle_policy(curr)) &&
+ likely(!task_has_idle_policy(p)))
goto preempt;
/*
@@ -7012,7 +7272,7 @@ static int task_hot(struct task_struct *p, struct lb_env *env)
if (p->sched_class != &fair_sched_class)
return 0;
- if (unlikely(p->policy == SCHED_IDLE))
+ if (unlikely(task_has_idle_policy(p)))
return 0;
/*
@@ -7896,16 +8156,16 @@ static bool update_nohz_stats(struct rq *rq, bool force)
* update_sg_lb_stats - Update sched_group's statistics for load balancing.
* @env: The load balancing environment.
* @group: sched_group whose statistics are to be updated.
- * @load_idx: Load index of sched_domain of this_cpu for load calc.
- * @local_group: Does group contain this_cpu.
* @sgs: variable to hold the statistics for this group.
- * @overload: Indicate pullable load (e.g. >1 runnable task).
+ * @sg_status: Holds flag indicating the status of the sched_group
*/
static inline void update_sg_lb_stats(struct lb_env *env,
- struct sched_group *group, int load_idx,
- int local_group, struct sg_lb_stats *sgs,
- bool *overload)
+ struct sched_group *group,
+ struct sg_lb_stats *sgs,
+ int *sg_status)
{
+ int local_group = cpumask_test_cpu(env->dst_cpu, sched_group_span(group));
+ int load_idx = get_sd_load_idx(env->sd, env->idle);
unsigned long load;
int i, nr_running;
@@ -7929,7 +8189,10 @@ static inline void update_sg_lb_stats(struct lb_env *env,
nr_running = rq->nr_running;
if (nr_running > 1)
- *overload = true;
+ *sg_status |= SG_OVERLOAD;
+
+ if (cpu_overutilized(i))
+ *sg_status |= SG_OVERUTILIZED;
#ifdef CONFIG_NUMA_BALANCING
sgs->nr_numa_running += rq->nr_numa_running;
@@ -7945,7 +8208,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
if (env->sd->flags & SD_ASYM_CPUCAPACITY &&
sgs->group_misfit_task_load < rq->misfit_task_load) {
sgs->group_misfit_task_load = rq->misfit_task_load;
- *overload = 1;
+ *sg_status |= SG_OVERLOAD;
}
}
@@ -8090,17 +8353,14 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
struct sched_group *sg = env->sd->groups;
struct sg_lb_stats *local = &sds->local_stat;
struct sg_lb_stats tmp_sgs;
- int load_idx;
- bool overload = false;
bool prefer_sibling = child && child->flags & SD_PREFER_SIBLING;
+ int sg_status = 0;
#ifdef CONFIG_NO_HZ_COMMON
if (env->idle == CPU_NEWLY_IDLE && READ_ONCE(nohz.has_blocked))
env->flags |= LBF_NOHZ_STATS;
#endif
- load_idx = get_sd_load_idx(env->sd, env->idle);
-
do {
struct sg_lb_stats *sgs = &tmp_sgs;
int local_group;
@@ -8115,8 +8375,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
update_group_capacity(env->sd, env->dst_cpu);
}
- update_sg_lb_stats(env, sg, load_idx, local_group, sgs,
- &overload);
+ update_sg_lb_stats(env, sg, sgs, &sg_status);
if (local_group)
goto next_group;
@@ -8165,9 +8424,15 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
env->fbq_type = fbq_classify_group(&sds->busiest_stat);
if (!env->sd->parent) {
+ struct root_domain *rd = env->dst_rq->rd;
+
/* update overload indicator if we are at root domain */
- if (READ_ONCE(env->dst_rq->rd->overload) != overload)
- WRITE_ONCE(env->dst_rq->rd->overload, overload);
+ WRITE_ONCE(rd->overload, sg_status & SG_OVERLOAD);
+
+ /* Update over-utilization (tipping point, U >= 0) indicator */
+ WRITE_ONCE(rd->overutilized, sg_status & SG_OVERUTILIZED);
+ } else if (sg_status & SG_OVERUTILIZED) {
+ WRITE_ONCE(env->dst_rq->rd->overutilized, SG_OVERUTILIZED);
}
}
@@ -8394,6 +8659,14 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
* this level.
*/
update_sd_lb_stats(env, &sds);
+
+ if (static_branch_unlikely(&sched_energy_present)) {
+ struct root_domain *rd = env->dst_rq->rd;
+
+ if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized))
+ goto out_balanced;
+ }
+
local = &sds.local_stat;
busiest = &sds.busiest_stat;
@@ -8910,13 +9183,22 @@ static int load_balance(int this_cpu, struct rq *this_rq,
sd->nr_balance_failed = 0;
out_one_pinned:
+ ld_moved = 0;
+
+ /*
+ * idle_balance() disregards balance intervals, so we could repeatedly
+ * reach this code, which would lead to balance_interval skyrocketting
+ * in a short amount of time. Skip the balance_interval increase logic
+ * to avoid that.
+ */
+ if (env.idle == CPU_NEWLY_IDLE)
+ goto out;
+
/* tune up the balancing interval */
- if (((env.flags & LBF_ALL_PINNED) &&
- sd->balance_interval < MAX_PINNED_INTERVAL) ||
- (sd->balance_interval < sd->max_interval))
+ if ((env.flags & LBF_ALL_PINNED &&
+ sd->balance_interval < MAX_PINNED_INTERVAL) ||
+ sd->balance_interval < sd->max_interval)
sd->balance_interval *= 2;
-
- ld_moved = 0;
out:
return ld_moved;
}
@@ -9281,7 +9563,7 @@ static void nohz_balancer_kick(struct rq *rq)
}
}
- sd = rcu_dereference(per_cpu(sd_asym, cpu));
+ sd = rcu_dereference(per_cpu(sd_asym_packing, cpu));
if (sd) {
for_each_cpu(i, sched_domain_span(sd)) {
if (i == cpu ||
@@ -9783,6 +10065,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
task_tick_numa(rq, curr);
update_misfit_status(curr, rq);
+ update_overutilized_status(task_rq(curr));
}
/*
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index e6802181900f6cd22e151170e4e63a1876dd4cb8..81faddba9e2011e2dff9a83f64e28fcc932e81c2 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -8,14 +8,14 @@
*/
#include "sched.h"
-DEFINE_STATIC_KEY_FALSE(housekeeping_overriden);
-EXPORT_SYMBOL_GPL(housekeeping_overriden);
+DEFINE_STATIC_KEY_FALSE(housekeeping_overridden);
+EXPORT_SYMBOL_GPL(housekeeping_overridden);
static cpumask_var_t housekeeping_mask;
static unsigned int housekeeping_flags;
int housekeeping_any_cpu(enum hk_flags flags)
{
- if (static_branch_unlikely(&housekeeping_overriden))
+ if (static_branch_unlikely(&housekeeping_overridden))
if (housekeeping_flags & flags)
return cpumask_any_and(housekeeping_mask, cpu_online_mask);
return smp_processor_id();
@@ -24,7 +24,7 @@ EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
const struct cpumask *housekeeping_cpumask(enum hk_flags flags)
{
- if (static_branch_unlikely(&housekeeping_overriden))
+ if (static_branch_unlikely(&housekeeping_overridden))
if (housekeeping_flags & flags)
return housekeeping_mask;
return cpu_possible_mask;
@@ -33,7 +33,7 @@ EXPORT_SYMBOL_GPL(housekeeping_cpumask);
void housekeeping_affine(struct task_struct *t, enum hk_flags flags)
{
- if (static_branch_unlikely(&housekeeping_overriden))
+ if (static_branch_unlikely(&housekeeping_overridden))
if (housekeeping_flags & flags)
set_cpus_allowed_ptr(t, housekeeping_mask);
}
@@ -41,7 +41,7 @@ EXPORT_SYMBOL_GPL(housekeeping_affine);
bool housekeeping_test_cpu(int cpu, enum hk_flags flags)
{
- if (static_branch_unlikely(&housekeeping_overriden))
+ if (static_branch_unlikely(&housekeeping_overridden))
if (housekeeping_flags & flags)
return cpumask_test_cpu(cpu, housekeeping_mask);
return true;
@@ -53,7 +53,7 @@ void __init housekeeping_init(void)
if (!housekeeping_flags)
return;
- static_branch_enable(&housekeeping_overriden);
+ static_branch_enable(&housekeeping_overridden);
if (housekeeping_flags & HK_FLAG_TICK)
sched_tick_offload_init();
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index a21ea60219293a0be6cc65ee63918f650b2606e1..e4f398ad9e73b778099cba7cd51553aea46bc6e0 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1498,6 +1498,14 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flag
#endif
}
+static inline void set_next_task(struct rq *rq, struct task_struct *p)
+{
+ p->se.exec_start = rq_clock_task(rq);
+
+ /* The running task is never eligible for pushing */
+ dequeue_pushable_task(rq, p);
+}
+
static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,
struct rt_rq *rt_rq)
{
@@ -1518,7 +1526,6 @@ static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,
static struct task_struct *_pick_next_task_rt(struct rq *rq)
{
struct sched_rt_entity *rt_se;
- struct task_struct *p;
struct rt_rq *rt_rq = &rq->rt;
do {
@@ -1527,10 +1534,7 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq)
rt_rq = group_rt_rq(rt_se);
} while (rt_rq);
- p = rt_task_of(rt_se);
- p->se.exec_start = rq_clock_task(rq);
-
- return p;
+ return rt_task_of(rt_se);
}
static struct task_struct *
@@ -1573,8 +1577,7 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
p = _pick_next_task_rt(rq);
- /* The running task is never eligible for pushing */
- dequeue_pushable_task(rq, p);
+ set_next_task(rq, p);
rt_queue_push_tasks(rq);
@@ -1810,10 +1813,8 @@ static int push_rt_task(struct rq *rq)
return 0;
retry:
- if (unlikely(next_task == rq->curr)) {
- WARN_ON(1);
+ if (WARN_ON(next_task == rq->curr))
return 0;
- }
/*
* It's possible that the next_task slipped in of
@@ -2355,12 +2356,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
static void set_curr_task_rt(struct rq *rq)
{
- struct task_struct *p = rq->curr;
-
- p->se.exec_start = rq_clock_task(rq);
-
- /* The running task is never eligible for pushing */
- dequeue_pushable_task(rq, p);
+ set_next_task(rq, rq->curr);
}
static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 4e524ab589c9b406d0f3bffa43e8da2793e20259..0ba08924e017e50711e0d26c0f737da0d5987141 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -45,6 +45,7 @@
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/delayacct.h>
+#include <linux/energy_model.h>
#include <linux/init_task.h>
#include <linux/kprobes.h>
#include <linux/kthread.h>
@@ -177,6 +178,11 @@ static inline bool valid_policy(int policy)
rt_policy(policy) || dl_policy(policy);
}
+static inline int task_has_idle_policy(struct task_struct *p)
+{
+ return idle_policy(p->policy);
+}
+
static inline int task_has_rt_policy(struct task_struct *p)
{
return rt_policy(p->policy);
@@ -632,7 +638,7 @@ struct dl_rq {
/*
* Deadline values of the currently executing and the
* earliest ready task on this rq. Caching these facilitates
- * the decision wether or not a ready but not running task
+ * the decision whether or not a ready but not running task
* should migrate somewhere else.
*/
struct {
@@ -704,6 +710,16 @@ static inline bool sched_asym_prefer(int a, int b)
return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b);
}
+struct perf_domain {
+ struct em_perf_domain *em_pd;
+ struct perf_domain *next;
+ struct rcu_head rcu;
+};
+
+/* Scheduling group status flags */
+#define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */
+#define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */
+
/*
* We add the notion of a root-domain which will be used to define per-domain
* variables. Each exclusive cpuset essentially defines an island domain by
@@ -726,6 +742,9 @@ struct root_domain {
*/
int overload;
+ /* Indicate one or more cpus over-utilized (tipping point) */
+ int overutilized;
+
/*
* The bit corresponding to a CPU gets set here if such CPU has more
* than one runnable -deadline task (as it is below for RT tasks).
@@ -756,6 +775,12 @@ struct root_domain {
struct cpupri cpupri;
unsigned long max_cpu_capacity;
+
+ /*
+ * NULL-terminated list of performance domains intersecting with the
+ * CPUs of the rd. Protected by RCU.
+ */
+ struct perf_domain *pd;
};
extern struct root_domain def_root_domain;
@@ -1285,7 +1310,8 @@ DECLARE_PER_CPU(int, sd_llc_size);
DECLARE_PER_CPU(int, sd_llc_id);
DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared);
DECLARE_PER_CPU(struct sched_domain *, sd_numa);
-DECLARE_PER_CPU(struct sched_domain *, sd_asym);
+DECLARE_PER_CPU(struct sched_domain *, sd_asym_packing);
+DECLARE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity);
extern struct static_key_false sched_asym_cpucapacity;
struct sched_group_capacity {
@@ -1429,7 +1455,7 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
#ifdef CONFIG_SMP
/*
* After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
- * successfuly executed on another CPU. We must ensure that updates of
+ * successfully executed on another CPU. We must ensure that updates of
* per-task data have been completed by this moment.
*/
smp_wmb();
@@ -1794,12 +1820,12 @@ static inline void add_nr_running(struct rq *rq, unsigned count)
rq->nr_running = prev_nr + count;
- if (prev_nr < 2 && rq->nr_running >= 2) {
#ifdef CONFIG_SMP
+ if (prev_nr < 2 && rq->nr_running >= 2) {
if (!READ_ONCE(rq->rd->overload))
WRITE_ONCE(rq->rd->overload, 1);
-#endif
}
+#endif
sched_update_tick_dependency(rq);
}
@@ -1854,27 +1880,6 @@ unsigned long arch_scale_freq_capacity(int cpu)
}
#endif
-#ifdef CONFIG_SMP
-#ifndef arch_scale_cpu_capacity
-static __always_inline
-unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
-{
- if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
- return sd->smt_gain / sd->span_weight;
-
- return SCHED_CAPACITY_SCALE;
-}
-#endif
-#else
-#ifndef arch_scale_cpu_capacity
-static __always_inline
-unsigned long arch_scale_cpu_capacity(void __always_unused *sd, int cpu)
-{
- return SCHED_CAPACITY_SCALE;
-}
-#endif
-#endif
-
#ifdef CONFIG_SMP
#ifdef CONFIG_PREEMPT
@@ -2207,6 +2212,31 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
#endif
#ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
+/**
+ * enum schedutil_type - CPU utilization type
+ * @FREQUENCY_UTIL: Utilization used to select frequency
+ * @ENERGY_UTIL: Utilization used during energy calculation
+ *
+ * The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time
+ * need to be aggregated differently depending on the usage made of them. This
+ * enum is used within schedutil_freq_util() to differentiate the types of
+ * utilization expected by the callers, and adjust the aggregation accordingly.
+ */
+enum schedutil_type {
+ FREQUENCY_UTIL,
+ ENERGY_UTIL,
+};
+
+unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs,
+ unsigned long max, enum schedutil_type type);
+
+static inline unsigned long schedutil_energy_util(int cpu, unsigned long cfs)
+{
+ unsigned long max = arch_scale_cpu_capacity(NULL, cpu);
+
+ return schedutil_freq_util(cpu, cfs, max, ENERGY_UTIL);
+}
+
static inline unsigned long cpu_bw_dl(struct rq *rq)
{
return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;
@@ -2233,6 +2263,11 @@ static inline unsigned long cpu_util_rt(struct rq *rq)
{
return READ_ONCE(rq->avg_rt.util_avg);
}
+#else /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
+static inline unsigned long schedutil_energy_util(int cpu, unsigned long cfs)
+{
+ return cfs;
+}
#endif
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
@@ -2262,3 +2297,13 @@ unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned
return util;
}
#endif
+
+#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
+#define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus)))
+#else
+#define perf_domain_span(pd) NULL
+#endif
+
+#ifdef CONFIG_SMP
+extern struct static_key_false sched_energy_present;
+#endif
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 8d7f15ba59163c3a496f0284c2473a0575d57958..3f35ba1d8fde51589b8234a5fb0f7dc831aa0140 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -201,6 +201,199 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
return 1;
}
+DEFINE_STATIC_KEY_FALSE(sched_energy_present);
+#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
+DEFINE_MUTEX(sched_energy_mutex);
+bool sched_energy_update;
+
+static void free_pd(struct perf_domain *pd)
+{
+ struct perf_domain *tmp;
+
+ while (pd) {
+ tmp = pd->next;
+ kfree(pd);
+ pd = tmp;
+ }
+}
+
+static struct perf_domain *find_pd(struct perf_domain *pd, int cpu)
+{
+ while (pd) {
+ if (cpumask_test_cpu(cpu, perf_domain_span(pd)))
+ return pd;
+ pd = pd->next;
+ }
+
+ return NULL;
+}
+
+static struct perf_domain *pd_init(int cpu)
+{
+ struct em_perf_domain *obj = em_cpu_get(cpu);
+ struct perf_domain *pd;
+
+ if (!obj) {
+ if (sched_debug())
+ pr_info("%s: no EM found for CPU%d\n", __func__, cpu);
+ return NULL;
+ }
+
+ pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+ if (!pd)
+ return NULL;
+ pd->em_pd = obj;
+
+ return pd;
+}
+
+static void perf_domain_debug(const struct cpumask *cpu_map,
+ struct perf_domain *pd)
+{
+ if (!sched_debug() || !pd)
+ return;
+
+ printk(KERN_DEBUG "root_domain %*pbl:", cpumask_pr_args(cpu_map));
+
+ while (pd) {
+ printk(KERN_CONT " pd%d:{ cpus=%*pbl nr_cstate=%d }",
+ cpumask_first(perf_domain_span(pd)),
+ cpumask_pr_args(perf_domain_span(pd)),
+ em_pd_nr_cap_states(pd->em_pd));
+ pd = pd->next;
+ }
+
+ printk(KERN_CONT "\n");
+}
+
+static void destroy_perf_domain_rcu(struct rcu_head *rp)
+{
+ struct perf_domain *pd;
+
+ pd = container_of(rp, struct perf_domain, rcu);
+ free_pd(pd);
+}
+
+static void sched_energy_set(bool has_eas)
+{
+ if (!has_eas && static_branch_unlikely(&sched_energy_present)) {
+ if (sched_debug())
+ pr_info("%s: stopping EAS\n", __func__);
+ static_branch_disable_cpuslocked(&sched_energy_present);
+ } else if (has_eas && !static_branch_unlikely(&sched_energy_present)) {
+ if (sched_debug())
+ pr_info("%s: starting EAS\n", __func__);
+ static_branch_enable_cpuslocked(&sched_energy_present);
+ }
+}
+
+/*
+ * EAS can be used on a root domain if it meets all the following conditions:
+ * 1. an Energy Model (EM) is available;
+ * 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
+ * 3. the EM complexity is low enough to keep scheduling overheads low;
+ * 4. schedutil is driving the frequency of all CPUs of the rd;
+ *
+ * The complexity of the Energy Model is defined as:
+ *
+ * C = nr_pd * (nr_cpus + nr_cs)
+ *
+ * with parameters defined as:
+ * - nr_pd: the number of performance domains
+ * - nr_cpus: the number of CPUs
+ * - nr_cs: the sum of the number of capacity states of all performance
+ * domains (for example, on a system with 2 performance domains,
+ * with 10 capacity states each, nr_cs = 2 * 10 = 20).
+ *
+ * It is generally not a good idea to use such a model in the wake-up path on
+ * very complex platforms because of the associated scheduling overheads. The
+ * arbitrary constraint below prevents that. It makes EAS usable up to 16 CPUs
+ * with per-CPU DVFS and less than 8 capacity states each, for example.
+ */
+#define EM_MAX_COMPLEXITY 2048
+
+extern struct cpufreq_governor schedutil_gov;
+static bool build_perf_domains(const struct cpumask *cpu_map)
+{
+ int i, nr_pd = 0, nr_cs = 0, nr_cpus = cpumask_weight(cpu_map);
+ struct perf_domain *pd = NULL, *tmp;
+ int cpu = cpumask_first(cpu_map);
+ struct root_domain *rd = cpu_rq(cpu)->rd;
+ struct cpufreq_policy *policy;
+ struct cpufreq_governor *gov;
+
+ /* EAS is enabled for asymmetric CPU capacity topologies. */
+ if (!per_cpu(sd_asym_cpucapacity, cpu)) {
+ if (sched_debug()) {
+ pr_info("rd %*pbl: CPUs do not have asymmetric capacities\n",
+ cpumask_pr_args(cpu_map));
+ }
+ goto free;
+ }
+
+ for_each_cpu(i, cpu_map) {
+ /* Skip already covered CPUs. */
+ if (find_pd(pd, i))
+ continue;
+
+ /* Do not attempt EAS if schedutil is not being used. */
+ policy = cpufreq_cpu_get(i);
+ if (!policy)
+ goto free;
+ gov = policy->governor;
+ cpufreq_cpu_put(policy);
+ if (gov != &schedutil_gov) {
+ if (rd->pd)
+ pr_warn("rd %*pbl: Disabling EAS, schedutil is mandatory\n",
+ cpumask_pr_args(cpu_map));
+ goto free;
+ }
+
+ /* Create the new pd and add it to the local list. */
+ tmp = pd_init(i);
+ if (!tmp)
+ goto free;
+ tmp->next = pd;
+ pd = tmp;
+
+ /*
+ * Count performance domains and capacity states for the
+ * complexity check.
+ */
+ nr_pd++;
+ nr_cs += em_pd_nr_cap_states(pd->em_pd);
+ }
+
+ /* Bail out if the Energy Model complexity is too high. */
+ if (nr_pd * (nr_cs + nr_cpus) > EM_MAX_COMPLEXITY) {
+ WARN(1, "rd %*pbl: Failed to start EAS, EM complexity is too high\n",
+ cpumask_pr_args(cpu_map));
+ goto free;
+ }
+
+ perf_domain_debug(cpu_map, pd);
+
+ /* Attach the new list of performance domains to the root domain. */
+ tmp = rd->pd;
+ rcu_assign_pointer(rd->pd, pd);
+ if (tmp)
+ call_rcu(&tmp->rcu, destroy_perf_domain_rcu);
+
+ return !!pd;
+
+free:
+ free_pd(pd);
+ tmp = rd->pd;
+ rcu_assign_pointer(rd->pd, NULL);
+ if (tmp)
+ call_rcu(&tmp->rcu, destroy_perf_domain_rcu);
+
+ return false;
+}
+#else
+static void free_pd(struct perf_domain *pd) { }
+#endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL*/
+
static void free_rootdomain(struct rcu_head *rcu)
{
struct root_domain *rd = container_of(rcu, struct root_domain, rcu);
@@ -211,6 +404,7 @@ static void free_rootdomain(struct rcu_head *rcu)
free_cpumask_var(rd->rto_mask);
free_cpumask_var(rd->online);
free_cpumask_var(rd->span);
+ free_pd(rd->pd);
kfree(rd);
}
@@ -397,7 +591,8 @@ DEFINE_PER_CPU(int, sd_llc_size);
DEFINE_PER_CPU(int, sd_llc_id);
DEFINE_PER_CPU(struct sched_domain_shared *, sd_llc_shared);
DEFINE_PER_CPU(struct sched_domain *, sd_numa);
-DEFINE_PER_CPU(struct sched_domain *, sd_asym);
+DEFINE_PER_CPU(struct sched_domain *, sd_asym_packing);
+DEFINE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity);
DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity);
static void update_top_cache_domain(int cpu)
@@ -423,7 +618,10 @@ static void update_top_cache_domain(int cpu)
rcu_assign_pointer(per_cpu(sd_numa, cpu), sd);
sd = highest_flag_domain(cpu, SD_ASYM_PACKING);
- rcu_assign_pointer(per_cpu(sd_asym, cpu), sd);
+ rcu_assign_pointer(per_cpu(sd_asym_packing, cpu), sd);
+
+ sd = lowest_flag_domain(cpu, SD_ASYM_CPUCAPACITY);
+ rcu_assign_pointer(per_cpu(sd_asym_cpucapacity, cpu), sd);
}
/*
@@ -1133,7 +1331,6 @@ sd_init(struct sched_domain_topology_level *tl,
.last_balance = jiffies,
.balance_interval = sd_weight,
- .smt_gain = 0,
.max_newidle_lb_cost = 0,
.next_decay_max_lb_cost = jiffies,
.child = child,
@@ -1164,7 +1361,6 @@ sd_init(struct sched_domain_topology_level *tl,
if (sd->flags & SD_SHARE_CPUCAPACITY) {
sd->imbalance_pct = 110;
- sd->smt_gain = 1178; /* ~15% */
} else if (sd->flags & SD_SHARE_PKG_RESOURCES) {
sd->imbalance_pct = 117;
@@ -1934,6 +2130,7 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
struct sched_domain_attr *dattr_new)
{
+ bool __maybe_unused has_eas = false;
int i, j, n;
int new_topology;
@@ -1961,8 +2158,8 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
/* Destroy deleted domains: */
for (i = 0; i < ndoms_cur; i++) {
for (j = 0; j < n && !new_topology; j++) {
- if (cpumask_equal(doms_cur[i], doms_new[j])
- && dattrs_equal(dattr_cur, i, dattr_new, j))
+ if (cpumask_equal(doms_cur[i], doms_new[j]) &&
+ dattrs_equal(dattr_cur, i, dattr_new, j))
goto match1;
}
/* No match - a current sched domain not in new doms_new[] */
@@ -1982,8 +2179,8 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
/* Build new domains: */
for (i = 0; i < ndoms_new; i++) {
for (j = 0; j < n && !new_topology; j++) {
- if (cpumask_equal(doms_new[i], doms_cur[j])
- && dattrs_equal(dattr_new, i, dattr_cur, j))
+ if (cpumask_equal(doms_new[i], doms_cur[j]) &&
+ dattrs_equal(dattr_new, i, dattr_cur, j))
goto match2;
}
/* No match - add a new doms_new */
@@ -1992,6 +2189,24 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
;
}
+#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
+ /* Build perf. domains: */
+ for (i = 0; i < ndoms_new; i++) {
+ for (j = 0; j < n && !sched_energy_update; j++) {
+ if (cpumask_equal(doms_new[i], doms_cur[j]) &&
+ cpu_rq(cpumask_first(doms_cur[j]))->rd->pd) {
+ has_eas = true;
+ goto match3;
+ }
+ }
+ /* No match - add perf. domains for a new rd */
+ has_eas |= build_perf_domains(doms_new[i]);
+match3:
+ ;
+ }
+ sched_energy_set(has_eas);
+#endif
+
/* Remember the new sched domains: */
if (doms_cur != &fallback_doms)
free_sched_domains(doms_cur, ndoms_cur);