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-rw-r--r--include/linux/sched.h53
-rw-r--r--include/linux/sched/sysctl.h5
-rw-r--r--include/trace/events/sched.h149
-rw-r--r--init/Kconfig9
-rw-r--r--kernel/sched/Makefile1
-rw-r--r--kernel/sched/core.c43
-rw-r--r--kernel/sched/fair.c20
-rw-r--r--kernel/sched/rt.c4
-rw-r--r--kernel/sched/sched.h34
-rw-r--r--kernel/sched/stop_task.c3
-rw-r--r--kernel/sched/walt.c1098
-rw-r--r--kernel/sched/walt.h57
-rw-r--r--kernel/sysctl.c23
13 files changed, 1498 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f1a28bafe7ea..ede29e8db82d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -317,6 +317,15 @@ extern char ___assert_task_state[1 - 2*!!(
/* Task command name length */
#define TASK_COMM_LEN 16
+enum task_event {
+ PUT_PREV_TASK = 0,
+ PICK_NEXT_TASK = 1,
+ TASK_WAKE = 2,
+ TASK_MIGRATE = 3,
+ TASK_UPDATE = 4,
+ IRQ_UPDATE = 5,
+};
+
#include <linux/spinlock.h>
/*
@@ -1276,6 +1285,41 @@ struct sched_statistics {
};
#endif
+#ifdef CONFIG_SCHED_WALT
+#define RAVG_HIST_SIZE_MAX 5
+
+/* ravg represents frequency scaled cpu-demand of tasks */
+struct ravg {
+ /*
+ * 'mark_start' marks the beginning of an event (task waking up, task
+ * starting to execute, task being preempted) within a window
+ *
+ * 'sum' represents how runnable a task has been within current
+ * window. It incorporates both running time and wait time and is
+ * frequency scaled.
+ *
+ * 'sum_history' keeps track of history of 'sum' seen over previous
+ * RAVG_HIST_SIZE windows. Windows where task was entirely sleeping are
+ * ignored.
+ *
+ * 'demand' represents maximum sum seen over previous
+ * sysctl_sched_ravg_hist_size windows. 'demand' could drive frequency
+ * demand for tasks.
+ *
+ * 'curr_window' represents task's contribution to cpu busy time
+ * statistics (rq->curr_runnable_sum) in current window
+ *
+ * 'prev_window' represents task's contribution to cpu busy time
+ * statistics (rq->prev_runnable_sum) in previous window
+ */
+ u64 mark_start;
+ u32 sum, demand;
+ u32 sum_history[RAVG_HIST_SIZE_MAX];
+ u32 curr_window, prev_window;
+ u16 active_windows;
+};
+#endif
+
struct sched_entity {
struct load_weight load; /* for load-balancing */
struct rb_node run_node;
@@ -1433,6 +1477,15 @@ struct task_struct {
const struct sched_class *sched_class;
struct sched_entity se;
struct sched_rt_entity rt;
+#ifdef CONFIG_SCHED_WALT
+ struct ravg ravg;
+ /*
+ * 'init_load_pct' represents the initial task load assigned to children
+ * of this task
+ */
+ u32 init_load_pct;
+#endif
+
#ifdef CONFIG_CGROUP_SCHED
struct task_group *sched_task_group;
#endif
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index 2834841c507e..710f58a28d63 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -43,6 +43,11 @@ extern unsigned int sysctl_sched_is_big_little;
extern unsigned int sysctl_sched_sync_hint_enable;
extern unsigned int sysctl_sched_initial_task_util;
extern unsigned int sysctl_sched_cstate_aware;
+#ifdef CONFIG_SCHED_WALT
+extern unsigned int sysctl_sched_use_walt_cpu_util;
+extern unsigned int sysctl_sched_use_walt_task_util;
+extern unsigned int sysctl_sched_walt_init_task_load_pct;
+#endif
enum sched_tunable_scaling {
SCHED_TUNABLESCALING_NONE,
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index debcf417c535..fa1b3df836bc 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -937,6 +937,155 @@ TRACE_EVENT(sched_tune_filter,
__entry->payoff, __entry->region)
);
+#ifdef CONFIG_SCHED_WALT
+struct rq;
+
+TRACE_EVENT(walt_update_task_ravg,
+
+ TP_PROTO(struct task_struct *p, struct rq *rq, int evt,
+ u64 wallclock, u64 irqtime),
+
+ TP_ARGS(p, rq, evt, wallclock, irqtime),
+
+ TP_STRUCT__entry(
+ __array( char, comm, TASK_COMM_LEN )
+ __field( pid_t, pid )
+ __field( pid_t, cur_pid )
+ __field(unsigned int, cur_freq )
+ __field( u64, wallclock )
+ __field( u64, mark_start )
+ __field( u64, delta_m )
+ __field( u64, win_start )
+ __field( u64, delta )
+ __field( u64, irqtime )
+ __field( int, evt )
+ __field(unsigned int, demand )
+ __field(unsigned int, sum )
+ __field( int, cpu )
+ __field( u64, cs )
+ __field( u64, ps )
+ __field( u32, curr_window )
+ __field( u32, prev_window )
+ __field( u64, nt_cs )
+ __field( u64, nt_ps )
+ __field( u32, active_windows )
+ ),
+
+ TP_fast_assign(
+ __entry->wallclock = wallclock;
+ __entry->win_start = rq->window_start;
+ __entry->delta = (wallclock - rq->window_start);
+ __entry->evt = evt;
+ __entry->cpu = rq->cpu;
+ __entry->cur_pid = rq->curr->pid;
+ __entry->cur_freq = rq->cur_freq;
+ memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
+ __entry->pid = p->pid;
+ __entry->mark_start = p->ravg.mark_start;
+ __entry->delta_m = (wallclock - p->ravg.mark_start);
+ __entry->demand = p->ravg.demand;
+ __entry->sum = p->ravg.sum;
+ __entry->irqtime = irqtime;
+ __entry->cs = rq->curr_runnable_sum;
+ __entry->ps = rq->prev_runnable_sum;
+ __entry->curr_window = p->ravg.curr_window;
+ __entry->prev_window = p->ravg.prev_window;
+ __entry->nt_cs = rq->nt_curr_runnable_sum;
+ __entry->nt_ps = rq->nt_prev_runnable_sum;
+ __entry->active_windows = p->ravg.active_windows;
+ ),
+
+ TP_printk("wc %llu ws %llu delta %llu event %d cpu %d cur_freq %u cur_pid %d task %d (%s) ms %llu delta %llu demand %u sum %u irqtime %llu"
+ " cs %llu ps %llu cur_window %u prev_window %u nt_cs %llu nt_ps %llu active_wins %u"
+ , __entry->wallclock, __entry->win_start, __entry->delta,
+ __entry->evt, __entry->cpu,
+ __entry->cur_freq, __entry->cur_pid,
+ __entry->pid, __entry->comm, __entry->mark_start,
+ __entry->delta_m, __entry->demand,
+ __entry->sum, __entry->irqtime,
+ __entry->cs, __entry->ps,
+ __entry->curr_window, __entry->prev_window,
+ __entry->nt_cs, __entry->nt_ps,
+ __entry->active_windows
+ )
+);
+
+TRACE_EVENT(walt_update_history,
+
+ TP_PROTO(struct rq *rq, struct task_struct *p, u32 runtime, int samples,
+ int evt),
+
+ TP_ARGS(rq, p, runtime, samples, evt),
+
+ TP_STRUCT__entry(
+ __array( char, comm, TASK_COMM_LEN )
+ __field( pid_t, pid )
+ __field(unsigned int, runtime )
+ __field( int, samples )
+ __field( int, evt )
+ __field( u64, demand )
+ __field(unsigned int, walt_avg )
+ __field(unsigned int, pelt_avg )
+ __array( u32, hist, RAVG_HIST_SIZE_MAX)
+ __field( int, cpu )
+ ),
+
+ TP_fast_assign(
+ memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
+ __entry->pid = p->pid;
+ __entry->runtime = runtime;
+ __entry->samples = samples;
+ __entry->evt = evt;
+ __entry->demand = p->ravg.demand;
+ __entry->walt_avg = (__entry->demand << 10) / walt_ravg_window,
+ __entry->pelt_avg = p->se.avg.util_avg;
+ memcpy(__entry->hist, p->ravg.sum_history,
+ RAVG_HIST_SIZE_MAX * sizeof(u32));
+ __entry->cpu = rq->cpu;
+ ),
+
+ TP_printk("%d (%s): runtime %u samples %d event %d demand %llu"
+ " walt %u pelt %u (hist: %u %u %u %u %u) cpu %d",
+ __entry->pid, __entry->comm,
+ __entry->runtime, __entry->samples, __entry->evt,
+ __entry->demand,
+ __entry->walt_avg,
+ __entry->pelt_avg,
+ __entry->hist[0], __entry->hist[1],
+ __entry->hist[2], __entry->hist[3],
+ __entry->hist[4], __entry->cpu)
+);
+
+TRACE_EVENT(walt_migration_update_sum,
+
+ TP_PROTO(struct rq *rq, struct task_struct *p),
+
+ TP_ARGS(rq, p),
+
+ TP_STRUCT__entry(
+ __field(int, cpu )
+ __field(int, pid )
+ __field( u64, cs )
+ __field( u64, ps )
+ __field( s64, nt_cs )
+ __field( s64, nt_ps )
+ ),
+
+ TP_fast_assign(
+ __entry->cpu = cpu_of(rq);
+ __entry->cs = rq->curr_runnable_sum;
+ __entry->ps = rq->prev_runnable_sum;
+ __entry->nt_cs = (s64)rq->nt_curr_runnable_sum;
+ __entry->nt_ps = (s64)rq->nt_prev_runnable_sum;
+ __entry->pid = p->pid;
+ ),
+
+ TP_printk("cpu %d: cs %llu ps %llu nt_cs %lld nt_ps %lld pid %d",
+ __entry->cpu, __entry->cs, __entry->ps,
+ __entry->nt_cs, __entry->nt_ps, __entry->pid)
+);
+#endif /* CONFIG_SCHED_WALT */
+
#endif /* CONFIG_SMP */
#endif /* _TRACE_SCHED_H */
diff --git a/init/Kconfig b/init/Kconfig
index 71f3ce810734..e71e35cf723c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -392,6 +392,15 @@ config IRQ_TIME_ACCOUNTING
endchoice
+config SCHED_WALT
+ bool "Support window based load tracking"
+ depends on SMP
+ help
+ This feature will allow the scheduler to maintain a tunable window
+ based set of metrics for tasks and runqueues. These metrics can be
+ used to guide task placement as well as task frequency requirements
+ for cpufreq governors.
+
config BSD_PROCESS_ACCT
bool "BSD Process Accounting"
depends on MULTIUSER
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 174762d8695b..623ce4bde0d5 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -15,6 +15,7 @@ obj-y += core.o loadavg.o clock.o cputime.o
obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o
obj-y += wait.o completion.o idle.o
obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o energy.o
+obj-$(CONFIG_SCHED_WALT) += walt.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
obj-$(CONFIG_SCHED_DEBUG) += debug.o
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b814c13f850f..4c981dfc34ee 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -89,6 +89,7 @@
#define CREATE_TRACE_POINTS
#include <trace/events/sched.h>
+#include "walt.h"
DEFINE_MUTEX(sched_domains_mutex);
DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
@@ -1085,7 +1086,9 @@ static struct rq *move_queued_task(struct rq *rq, struct task_struct *p, int new
dequeue_task(rq, p, 0);
p->on_rq = TASK_ON_RQ_MIGRATING;
+ double_lock_balance(rq, cpu_rq(new_cpu));
set_task_cpu(p, new_cpu);
+ double_unlock_balance(rq, cpu_rq(new_cpu));
raw_spin_unlock(&rq->lock);
rq = cpu_rq(new_cpu);
@@ -1309,6 +1312,8 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
p->sched_class->migrate_task_rq(p);
p->se.nr_migrations++;
perf_event_task_migrate(p);
+
+ walt_fixup_busy_time(p, new_cpu);
}
__set_task_cpu(p, new_cpu);
@@ -1937,6 +1942,10 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
{
unsigned long flags;
int cpu, success = 0;
+#ifdef CONFIG_SMP
+ struct rq *rq;
+ u64 wallclock;
+#endif
/*
* If we are going to wake up a thread waiting for CONDITION we
@@ -1994,6 +2003,14 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
*/
smp_rmb();
+ rq = cpu_rq(task_cpu(p));
+
+ raw_spin_lock(&rq->lock);
+ wallclock = walt_ktime_clock();
+ walt_update_task_ravg(rq->curr, rq, TASK_UPDATE, wallclock, 0);
+ walt_update_task_ravg(p, rq, TASK_WAKE, wallclock, 0);
+ raw_spin_unlock(&rq->lock);
+
p->sched_contributes_to_load = !!task_contributes_to_load(p);
p->state = TASK_WAKING;
@@ -2001,10 +2018,12 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
p->sched_class->task_waking(p);
cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags);
+
if (task_cpu(p) != cpu) {
wake_flags |= WF_MIGRATED;
set_task_cpu(p, cpu);
}
+
#endif /* CONFIG_SMP */
ttwu_queue(p, cpu);
@@ -2053,8 +2072,13 @@ static void try_to_wake_up_local(struct task_struct *p)
trace_sched_waking(p);
- if (!task_on_rq_queued(p))
+ if (!task_on_rq_queued(p)) {
+ u64 wallclock = walt_ktime_clock();
+
+ walt_update_task_ravg(rq->curr, rq, TASK_UPDATE, wallclock, 0);
+ walt_update_task_ravg(p, rq, TASK_WAKE, wallclock, 0);
ttwu_activate(rq, p, ENQUEUE_WAKEUP);
+ }
ttwu_do_wakeup(rq, p, 0);
ttwu_stat(p, smp_processor_id(), 0);
@@ -2120,6 +2144,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
p->se.nr_migrations = 0;
p->se.vruntime = 0;
INIT_LIST_HEAD(&p->se.group_node);
+ walt_init_new_task_load(p);
#ifdef CONFIG_SCHEDSTATS
memset(&p->se.statistics, 0, sizeof(p->se.statistics));
@@ -2387,6 +2412,9 @@ void wake_up_new_task(struct task_struct *p)
struct rq *rq;
raw_spin_lock_irqsave(&p->pi_lock, flags);
+
+ walt_init_new_task_load(p);
+
/* Initialize new task's runnable average */
init_entity_runnable_average(&p->se);
#ifdef CONFIG_SMP
@@ -2399,6 +2427,7 @@ void wake_up_new_task(struct task_struct *p)
#endif
rq = __task_rq_lock(p);
+ walt_mark_task_starting(p);
activate_task(rq, p, ENQUEUE_WAKEUP_NEW);
p->on_rq = TASK_ON_RQ_QUEUED;
trace_sched_wakeup_new(p);
@@ -2948,9 +2977,12 @@ void scheduler_tick(void)
sched_clock_tick();
raw_spin_lock(&rq->lock);
+ walt_set_window_start(rq);
update_rq_clock(rq);
curr->sched_class->task_tick(rq, curr, 0);
update_cpu_load_active(rq);
+ walt_update_task_ravg(rq->curr, rq, TASK_UPDATE,
+ walt_ktime_clock(), 0);
calc_global_load_tick(rq);
sched_freq_tick(cpu);
raw_spin_unlock(&rq->lock);
@@ -3189,6 +3221,7 @@ static void __sched notrace __schedule(bool preempt)
unsigned long *switch_count;
struct rq *rq;
int cpu;
+ u64 wallclock;
cpu = smp_processor_id();
rq = cpu_rq(cpu);
@@ -3250,6 +3283,9 @@ static void __sched notrace __schedule(bool preempt)
update_rq_clock(rq);
next = pick_next_task(rq, prev);
+ wallclock = walt_ktime_clock();
+ walt_update_task_ravg(prev, rq, PUT_PREV_TASK, wallclock, 0);
+ walt_update_task_ravg(next, rq, PICK_NEXT_TASK, wallclock, 0);
clear_tsk_need_resched(prev);
clear_preempt_need_resched();
rq->clock_skip_update = 0;
@@ -5672,6 +5708,9 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_UP_PREPARE:
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ walt_set_window_start(rq);
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
rq->calc_load_update = calc_load_update;
account_reset_rq(rq);
break;
@@ -5692,6 +5731,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
sched_ttwu_pending();
/* Update our root-domain */
raw_spin_lock_irqsave(&rq->lock, flags);
+ walt_migrate_sync_cpu(cpu);
if (rq->rd) {
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
set_rq_offline(rq);
@@ -7536,6 +7576,7 @@ void __init sched_init_smp(void)
{
cpumask_var_t non_isolated_cpus;
+ walt_init_cpu_efficiency();
alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 84f5e12c8e12..15b8a8f34bd9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -30,11 +30,13 @@
#include <linux/mempolicy.h>
#include <linux/migrate.h>
#include <linux/task_work.h>
+#include <linux/module.h>
#include <trace/events/sched.h>
#include "sched.h"
#include "tune.h"
+#include "walt.h"
/*
* Targeted preemption latency for CPU-bound tasks:
@@ -56,6 +58,10 @@ unsigned int sysctl_sched_sync_hint_enable = 1;
unsigned int sysctl_sched_initial_task_util = 0;
unsigned int sysctl_sched_cstate_aware = 1;
+#ifdef CONFIG_SCHED_WALT
+unsigned int sysctl_sched_use_walt_cpu_util = 1;
+unsigned int sysctl_sched_use_walt_task_util = 1;
+#endif
/*
* The initial- and re-scaling of tunables is configurable
* (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
@@ -4225,6 +4231,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
if (cfs_rq_throttled(cfs_rq))
break;
cfs_rq->h_nr_running++;
+ walt_inc_cfs_cumulative_runnable_avg(cfs_rq, p);
flags = ENQUEUE_WAKEUP;
}
@@ -4232,6 +4239,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
cfs_rq->h_nr_running++;
+ walt_inc_cfs_cumulative_runnable_avg(cfs_rq, p);
if (cfs_rq_throttled(cfs_rq))
break;
@@ -4246,6 +4254,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
#ifdef CONFIG_SMP
if (!se) {
+ walt_inc_cumulative_runnable_avg(rq, p);
if (!task_new && !rq->rd->overutilized &&
cpu_overutilized(rq->cpu))
rq->rd->overutilized = true;
@@ -4295,6 +4304,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
if (cfs_rq_throttled(cfs_rq))
break;
cfs_rq->h_nr_running--;
+ walt_dec_cfs_cumulative_runnable_avg(cfs_rq, p);
/* Don't dequeue parent if it has other entities besides us */
if (cfs_rq->load.weight) {
@@ -4315,6 +4325,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
cfs_rq->h_nr_running--;
+ walt_dec_cfs_cumulative_runnable_avg(cfs_rq, p);
if (cfs_rq_throttled(cfs_rq))
break;
@@ -4329,6 +4340,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
#ifdef CONFIG_SMP
if (!se) {
+ walt_dec_cumulative_runnable_avg(rq, p);
/*
* We want to potentially trigger a freq switch
@@ -5228,6 +5240,12 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
static inline unsigned long task_util(struct task_struct *p)
{
+#ifdef CONFIG_SCHED_WALT
+ if (!walt_disabled && sysctl_sched_use_walt_task_util) {
+ unsigned long demand = p->ravg.demand;
+ return (demand << 10) / walt_ravg_window;
+ }
+#endif
return p->se.avg.util_avg;
}
@@ -6620,7 +6638,9 @@ static void detach_task(struct task_struct *p, struct lb_env *env)
deactivate_task(env->src_rq, p, 0);
p->on_rq = TASK_ON_RQ_MIGRATING;
+ double_lock_balance(env->src_rq, env->dst_rq);
set_task_cpu(p, env->dst_cpu);
+ double_unlock_balance(env->src_rq, env->dst_rq);
}
/*
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 9694204660b7..be700bfa1ae4 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -8,6 +8,8 @@
#include <linux/slab.h>
#include <linux/irq_work.h>
+#include "walt.h"
+
int sched_rr_timeslice = RR_TIMESLICE;
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
@@ -1261,6 +1263,7 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
rt_se->timeout = 0;
enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD);
+ walt_inc_cumulative_runnable_avg(rq, p);
if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
enqueue_pushable_task(rq, p);
@@ -1272,6 +1275,7 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
update_curr_rt(rq);
dequeue_rt_entity(rt_se);
+ walt_dec_cumulative_runnable_avg(rq, p);
dequeue_pushable_task(rq, p);
}
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 1b838cff2f20..f48fb371913a 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -410,6 +410,10 @@ struct cfs_rq {
struct list_head leaf_cfs_rq_list;
struct task_group *tg; /* group that "owns" this runqueue */
+#ifdef CONFIG_SCHED_WALT
+ u64 cumulative_runnable_avg;
+#endif
+
#ifdef CONFIG_CFS_BANDWIDTH
int runtime_enabled;
u64 runtime_expires;
@@ -663,6 +667,27 @@ struct rq {
u64 max_idle_balance_cost;
#endif
+#ifdef CONFIG_SCHED_WALT
+ /*
+ * max_freq = user or thermal defined maximum
+ * max_possible_freq = maximum supported by hardware
+ */
+ unsigned int cur_freq, max_freq, min_freq, max_possible_freq;
+ struct cpumask freq_domain_cpumask;
+
+ u64 cumulative_runnable_avg;
+ int efficiency; /* Differentiate cpus with different IPC capability */
+ int load_scale_factor;
+ int capacity;
+ int max_possible_capacity;
+ u64 window_start;
+ u64 curr_runnable_sum;
+ u64 prev_runnable_sum;
+ u64 nt_curr_runnable_sum;
+ u64 nt_prev_runnable_sum;
+#endif /* CONFIG_SCHED_WALT */
+
+
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
u64 prev_irq_time;
#endif
@@ -1513,6 +1538,10 @@ static inline unsigned long capacity_orig_of(int cpu)
return cpu_rq(cpu)->cpu_capacity_orig;
}
+extern unsigned int sysctl_sched_use_walt_cpu_util;
+extern unsigned int walt_ravg_window;
+extern unsigned int walt_disabled;
+
/*
* cpu_util returns the amount of capacity of a CPU that is used by CFS
* tasks. The unit of the return value must be the one of capacity so we can
@@ -1544,6 +1573,11 @@ static inline unsigned long __cpu_util(int cpu, int delta)
unsigned long util = cpu_rq(cpu)->cfs.avg.util_avg;
unsigned long capacity = capacity_orig_of(cpu);
+#ifdef CONFIG_SCHED_WALT
+ if (!walt_disabled && sysctl_sched_use_walt_cpu_util)
+ util = (cpu_rq(cpu)->prev_runnable_sum << SCHED_LOAD_SHIFT) /
+ walt_ravg_window;
+#endif
delta += util;
if (delta < 0)
return 0;
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index cbc67da10954..61f852d46858 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -1,4 +1,5 @@
#include "sched.h"
+#include "walt.h"
/*
* stop-task scheduling class.
@@ -42,12 +43,14 @@ static void
enqueue_task_stop(struct rq *rq, struct task_struct *p, int flags)
{
add_nr_running(rq, 1);
+ walt_inc_cumulative_runnable_avg(rq, p);
}
static void
dequeue_task_stop(struct rq *rq, struct task_struct *p, int flags)
{
sub_nr_running(rq, 1);
+ walt_dec_cumulative_runnable_avg(rq, p);
}
static void yield_task_stop(struct rq *rq)
diff --git a/kernel/sched/walt.c b/kernel/sched/walt.c
new file mode 100644
index 000000000000..1dff3d2e2358
--- /dev/null
+++ b/kernel/sched/walt.c
@@ -0,0 +1,1098 @@
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ *
+ * Window Assisted Load Tracking (WALT) implementation credits:
+ * Srivatsa Vaddagiri, Steve Muckle, Syed Rameez Mustafa, Joonwoo Park,
+ * Pavan Kumar Kondeti, Olav Haugan
+ *
+ * 2016-03-06: Integration with EAS/refactoring by Vikram Mulukutla
+ * and Todd Kjos
+ */
+
+#include <linux/syscore_ops.h>
+#include <linux/cpufreq.h>
+#include <trace/events/sched.h>
+#include "sched.h"
+#include "walt.h"
+
+#define WINDOW_STATS_RECENT 0
+#define WINDOW_STATS_MAX 1
+#define WINDOW_STATS_MAX_RECENT_AVG 2
+#define WINDOW_STATS_AVG 3
+#define WINDOW_STATS_INVALID_POLICY 4
+
+#define EXITING_TASK_MARKER 0xdeaddead
+
+static __read_mostly unsigned int walt_ravg_hist_size = 5;
+static __read_mostly unsigned int walt_window_stats_policy =
+ WINDOW_STATS_MAX_RECENT_AVG;
+static __read_mostly unsigned int walt_account_wait_time = 1;
+static __read_mostly unsigned int walt_freq_account_wait_time = 0;
+static __read_mostly unsigned int walt_io_is_busy = 0;
+
+unsigned int sysctl_sched_walt_init_task_load_pct = 15;
+
+/* 1 -> use PELT based load stats, 0 -> use window-based load stats */
+unsigned int __read_mostly walt_disabled = 0;
+
+static unsigned int max_possible_efficiency = 1024;
+static unsigned int min_possible_efficiency = 1024;
+
+/*
+ * Maximum possible frequency across all cpus. Task demand and cpu
+ * capacity (cpu_power) metrics are scaled in reference to it.
+ */
+static unsigned int max_possible_freq = 1;
+
+/*
+ * Minimum possible max_freq across all cpus. This will be same as
+ * max_possible_freq on homogeneous systems and could be different from
+ * max_possible_freq on heterogenous systems. min_max_freq is used to derive
+ * capacity (cpu_power) of cpus.
+ */
+static unsigned int min_max_freq = 1;
+
+static unsigned int max_capacity = 1024;
+static unsigned int min_capacity = 1024;
+static unsigned int max_load_scale_factor = 1024;
+static unsigned int max_possible_capacity = 1024;
+
+/* Mask of all CPUs that have max_possible_capacity */
+static cpumask_t mpc_mask = CPU_MASK_ALL;
+
+/* Window size (in ns) */
+__read_mostly unsigned int walt_ravg_window = 20000000;
+
+/* Min window size (in ns) = 10ms */
+#define MIN_SCHED_RAVG_WINDOW 10000000
+
+/* Max window size (in ns) = 1s */
+#define MAX_SCHED_RAVG_WINDOW 1000000000
+
+static unsigned int sync_cpu;
+static ktime_t ktime_last;
+static bool walt_ktime_suspended;
+
+static unsigned int task_load(struct task_struct *p)
+{
+ return p->ravg.demand;
+}
+
+void
+walt_inc_cumulative_runnable_avg(struct rq *rq,
+ struct task_struct *p)
+{
+ rq->cumulative_runnable_avg += p->ravg.demand;
+}
+
+void
+walt_dec_cumulative_runnable_avg(struct rq *rq,
+ struct task_struct *p)
+{
+ rq->cumulative_runnable_avg -= p->ravg.demand;
+ BUG_ON((s64)rq->cumulative_runnable_avg < 0);
+}
+
+static void
+fixup_cumulative_runnable_avg(struct rq *rq,
+ struct task_struct *p, s64 task_load_delta)
+{
+ rq->cumulative_runnable_avg += task_load_delta;
+ if ((s64)rq->cumulative_runnable_avg < 0)
+ panic("cra less than zero: tld: %lld, task_load(p) = %u\n",
+ task_load_delta, task_load(p));
+}
+
+u64 walt_ktime_clock(void)
+{
+ if (unlikely(walt_ktime_suspended))
+ return ktime_to_ns(ktime_last);
+ return ktime_get_ns();
+}
+
+static void walt_resume(void)
+{
+ walt_ktime_suspended = false;
+}
+
+static int walt_suspend(void)
+{
+ ktime_last = ktime_get();
+ walt_ktime_suspended = true;
+ return 0;
+}
+
+static struct syscore_ops walt_syscore_ops = {
+ .resume = walt_resume,
+ .suspend = walt_suspend
+};
+
+static int __init walt_init_ops(void)
+{
+ register_syscore_ops(&walt_syscore_ops);
+ return 0;
+}
+late_initcall(walt_init_ops);
+
+void walt_inc_cfs_cumulative_runnable_avg(struct cfs_rq *cfs_rq,
+ struct task_struct *p)
+{
+ cfs_rq->cumulative_runnable_avg += p->ravg.demand;
+}
+
+void walt_dec_cfs_cumulative_runnable_avg(struct cfs_rq *cfs_rq,
+ struct task_struct *p)
+{
+ cfs_rq->cumulative_runnable_avg -= p->ravg.demand;
+}
+
+static int exiting_task(struct task_struct *p)
+{
+ if (p->flags & PF_EXITING) {
+ if (p->ravg.sum_history[0] != EXITING_TASK_MARKER) {
+ p->ravg.sum_history[0] = EXITING_TASK_MARKER;
+ }
+ return 1;
+ }
+ return 0;
+}
+
+static int __init set_walt_ravg_window(char *str)
+{
+ get_option(&str, &walt_ravg_window);
+
+ walt_disabled = (walt_ravg_window < MIN_SCHED_RAVG_WINDOW ||
+ walt_ravg_window > MAX_SCHED_RAVG_WINDOW);
+ return 0;
+}
+
+early_param("walt_ravg_window", set_walt_ravg_window);
+
+static void
+update_window_start(struct rq *rq, u64 wallclock)
+{
+ s64 delta;
+ int nr_windows;
+
+ delta = wallclock - rq->window_start;
+ BUG_ON(delta < 0);
+ if (delta < walt_ravg_window)
+ return;
+
+ nr_windows = div64_u64(delta, walt_ravg_window);
+ rq->window_start += (u64)nr_windows * (u64)walt_ravg_window;
+}
+
+static u64 scale_exec_time(u64 delta, struct rq *rq)
+{
+ unsigned int cur_freq = rq->cur_freq;
+ int sf;
+
+ if (unlikely(cur_freq > max_possible_freq))
+ cur_freq = rq->max_possible_freq;
+
+ /* round up div64 */
+ delta = div64_u64(delta * cur_freq + max_possible_freq - 1,
+ max_possible_freq);
+
+ sf = DIV_ROUND_UP(rq->efficiency * 1024, max_possible_efficiency);
+
+ delta *= sf;
+ delta >>= 10;
+
+ return delta;
+}
+
+static int cpu_is_waiting_on_io(struct rq *rq)
+{
+ if (!walt_io_is_busy)
+ return 0;
+
+ return atomic_read(&rq->nr_iowait);
+}
+
+static int account_busy_for_cpu_time(struct rq *rq, struct task_struct *p,
+ u64 irqtime, int event)
+{
+ if (is_idle_task(p)) {
+ /* TASK_WAKE && TASK_MIGRATE is not possible on idle task! */
+ if (event == PICK_NEXT_TASK)
+ return 0;
+
+ /* PUT_PREV_TASK, TASK_UPDATE && IRQ_UPDATE are left */
+ return irqtime || cpu_is_waiting_on_io(rq);
+ }
+
+ if (event == TASK_WAKE)
+ return 0;
+
+ if (event == PUT_PREV_TASK || event == IRQ_UPDATE ||
+ event == TASK_UPDATE)
+ return 1;
+
+ /* Only TASK_MIGRATE && PICK_NEXT_TASK left */
+ return walt_freq_account_wait_time;
+}
+
+/*
+ * Account cpu activity in its busy time counters (rq->curr/prev_runnable_sum)
+ */
+static void update_cpu_busy_time(struct task_struct *p, struct rq *rq,
+ int event, u64 wallclock, u64 irqtime)
+{
+ int new_window, nr_full_windows = 0;
+ int p_is_curr_task = (p == rq->curr);
+ u64 mark_start = p->ravg.mark_start;
+ u64 window_start = rq->window_start;
+ u32 window_size = walt_ravg_window;
+ u64 delta;
+
+ new_window = mark_start < window_start;
+ if (new_window) {
+ nr_full_windows = div64_u64((window_start - mark_start),
+ window_size);
+ if (p->ravg.active_windows < USHRT_MAX)
+ p->ravg.active_windows++;
+ }
+
+ /* Handle per-task window rollover. We don't care about the idle
+ * task or exiting tasks. */
+ if (new_window && !is_idle_task(p) && !exiting_task(p)) {
+ u32 curr_window = 0;
+
+ if (!nr_full_windows)
+ curr_window = p->ravg.curr_window;
+
+ p->ravg.prev_window = curr_window;
+ p->ravg.curr_window = 0;
+ }
+
+ if (!account_busy_for_cpu_time(rq, p, irqtime, event)) {
+ /* account_busy_for_cpu_time() = 0, so no update to the
+ * task's current window needs to be made. This could be
+ * for example
+ *
+ * - a wakeup event on a task within the current
+ * window (!new_window below, no action required),
+ * - switching to a new task from idle (PICK_NEXT_TASK)
+ * in a new window where irqtime is 0 and we aren't
+ * waiting on IO */
+
+ if (!new_window)
+ return;
+
+ /* A new window has started. The RQ demand must be rolled
+ * over if p is the current task. */
+ if (p_is_curr_task) {
+ u64 prev_sum = 0;
+
+ /* p is either idle task or an exiting task */
+ if (!nr_full_windows) {
+ prev_sum = rq->curr_runnable_sum;
+ }
+
+ rq->prev_runnable_sum = prev_sum;
+ rq->curr_runnable_sum = 0;
+ }
+
+ return;
+ }
+
+ if (!new_window) {
+ /* account_busy_for_cpu_time() = 1 so busy time needs
+ * to be accounted to the current window. No rollover
+ * since we didn't start a new window. An example of this is
+ * when a task starts execution and then sleeps within the
+ * same window. */
+
+ if (!irqtime || !is_idle_task(p) || cpu_is_waiting_on_io(rq))
+ delta = wallclock - mark_start;
+ else
+ delta = irqtime;
+ delta = scale_exec_time(delta, rq);
+ rq->curr_runnable_sum += delta;
+ if (!is_idle_task(p) && !exiting_task(p))
+ p->ravg.curr_window += delta;
+
+ return;
+ }
+
+ if (!p_is_curr_task) {
+ /* account_busy_for_cpu_time() = 1 so busy time needs
+ * to be accounted to the current window. A new window
+ * has also started, but p is not the current task, so the
+ * window is not rolled over - just split up and account
+ * as necessary into curr and prev. The window is only
+ * rolled over when a new window is processed for the current
+ * task.
+ *
+ * Irqtime can't be accounted by a task that isn't the
+ * currently running task. */
+
+ if (!nr_full_windows) {
+ /* A full window hasn't elapsed, account partial
+ * contribution to previous completed window. */
+ delta = scale_exec_time(window_start - mark_start, rq);
+ if (!exiting_task(p))
+ p->ravg.prev_window += delta;
+ } else {
+ /* Since at least one full window has elapsed,
+ * the contribution to the previous window is the
+ * full window (window_size). */
+ delta = scale_exec_time(window_size, rq);
+ if (!exiting_task(p))
+ p->ravg.prev_window = delta;
+ }
+ rq->prev_runnable_sum += delta;
+
+ /* Account piece of busy time in the current window. */
+ delta = scale_exec_time(wallclock - window_start, rq);
+ rq->curr_runnable_sum += delta;
+ if (!exiting_task(p))
+ p->ravg.curr_window = delta;
+
+ return;
+ }
+
+ if (!irqtime || !is_idle_task(p) || cpu_is_waiting_on_io(rq)) {
+ /* account_busy_for_cpu_time() = 1 so busy time needs
+ * to be accounted to the current window. A new window
+ * has started and p is the current task so rollover is
+ * needed. If any of these three above conditions are true
+ * then this busy time can't be accounted as irqtime.
+ *
+ * Busy time for the idle task or exiting tasks need not
+ * be accounted.
+ *
+ * An example of this would be a task that starts execution
+ * and then sleeps once a new window has begun. */
+
+ if (!nr_full_windows) {
+ /* A full window hasn't elapsed, account partial
+ * contribution to previous completed window. */
+ delta = scale_exec_time(window_start - mark_start, rq);
+ if (!is_idle_task(p) && !exiting_task(p))
+ p->ravg.prev_window += delta;
+
+ delta += rq->curr_runnable_sum;
+ } else {
+ /* Since at least one full window has elapsed,
+ * the contribution to the previous window is the
+ * full window (window_size). */
+ delta = scale_exec_time(window_size, rq);
+ if (!is_idle_task(p) && !exiting_task(p))
+ p->ravg.prev_window = delta;
+
+ }
+ /*
+ * Rollover for normal runnable sum is done here by overwriting
+ * the values in prev_runnable_sum and curr_runnable_sum.
+ * Rollover for new task runnable sum has completed by previous
+ * if-else statement.
+ */
+ rq->prev_runnable_sum = delta;
+
+ /* Account piece of busy time in the current window. */
+ delta = scale_exec_time(wallclock - window_start, rq);
+ rq->curr_runnable_sum = delta;
+ if (!is_idle_task(p) && !exiting_task(p))
+ p->ravg.curr_window = delta;
+
+ return;
+ }
+
+ if (irqtime) {
+ /* account_busy_for_cpu_time() = 1 so busy time needs
+ * to be accounted to the current window. A new window
+ * has started and p is the current task so rollover is
+ * needed. The current task must be the idle task because
+ * irqtime is not accounted for any other task.
+ *
+ * Irqtime will be accounted each time we process IRQ activity
+ * after a period of idleness, so we know the IRQ busy time
+ * started at wallclock - irqtime. */
+
+ BUG_ON(!is_idle_task(p));
+ mark_start = wallclock - irqtime;
+
+ /* Roll window over. If IRQ busy time was just in the current
+ * window then that is all that need be accounted. */
+ rq->prev_runnable_sum = rq->curr_runnable_sum;
+ if (mark_start > window_start) {
+ rq->curr_runnable_sum = scale_exec_time(irqtime, rq);
+ return;
+ }
+
+ /* The IRQ busy time spanned multiple windows. Process the
+ * busy time preceding the current window start first. */
+ delta = window_start - mark_start;
+ if (delta > window_size)
+ delta = window_size;
+ delta = scale_exec_time(delta, rq);
+ rq->prev_runnable_sum += delta;
+
+ /* Process the remaining IRQ busy time in the current window. */
+ delta = wallclock - window_start;
+ rq->curr_runnable_sum = scale_exec_time(delta, rq);
+
+ return;
+ }
+
+ BUG();
+}
+
+static int account_busy_for_task_demand(struct task_struct *p, int event)
+{
+ /* No need to bother updating task demand for exiting tasks
+ * or the idle task. */
+ if (exiting_task(p) || is_idle_task(p))
+ return 0;
+
+ /* When a task is waking up it is completing a segment of non-busy
+ * time. Likewise, if wait time is not treated as busy time, then
+ * when a task begins to run or is migrated, it is not running and
+ * is completing a segment of non-busy time. */
+ if (event == TASK_WAKE || (!walt_account_wait_time &&
+ (event == PICK_NEXT_TASK || event == TASK_MIGRATE)))
+ return 0;
+
+ return 1;
+}
+
+/*
+ * Called when new window is starting for a task, to record cpu usage over
+ * recently concluded window(s). Normally 'samples' should be 1. It can be > 1
+ * when, say, a real-time task runs without preemption for several windows at a
+ * stretch.
+ */
+static void update_history(struct rq *rq, struct task_struct *p,
+ u32 runtime, int samples, int event)
+{
+ u32 *hist = &p->ravg.sum_history[0];
+ int ridx, widx;
+ u32 max = 0, avg, demand;
+ u64 sum = 0;
+
+ /* Ignore windows where task had no activity */
+ if (!runtime || is_idle_task(p) || exiting_task(p) || !samples)
+ goto done;
+
+ /* Push new 'runtime' value onto stack */
+ widx = walt_ravg_hist_size - 1;
+ ridx = widx - samples;
+ for (; ridx >= 0; --widx, --ridx) {
+ hist[widx] = hist[ridx];
+ sum += hist[widx];
+ if (hist[widx] > max)
+ max = hist[widx];
+ }
+
+ for (widx = 0; widx < samples && widx < walt_ravg_hist_size; widx++) {
+ hist[widx] = runtime;
+ sum += hist[widx];
+ if (hist[widx] > max)
+ max = hist[widx];
+ }
+
+ p->ravg.sum = 0;
+
+ if (walt_window_stats_policy == WINDOW_STATS_RECENT) {
+ demand = runtime;
+ } else if (walt_window_stats_policy == WINDOW_STATS_MAX) {
+ demand = max;
+ } else {
+ avg = div64_u64(sum, walt_ravg_hist_size);
+ if (walt_window_stats_policy == WINDOW_STATS_AVG)
+ demand = avg;
+ else
+ demand = max(avg, runtime);
+ }
+
+ /*
+ * A throttled deadline sched class task gets dequeued without
+ * changing p->on_rq. Since the dequeue decrements hmp stats
+ * avoid decrementing it here again.
+ */
+ if (task_on_rq_queued(p) && (!task_has_dl_policy(p) ||
+ !p->dl.dl_throttled))
+ fixup_cumulative_runnable_avg(rq, p, demand);
+
+ p->ravg.demand = demand;
+
+done:
+ trace_walt_update_history(rq, p, runtime, samples, event);
+ return;
+}
+
+static void add_to_task_demand(struct rq *rq, struct task_struct *p,
+ u64 delta)
+{
+ delta = scale_exec_time(delta, rq);
+ p->ravg.sum += delta;
+ if (unlikely(p->ravg.sum > walt_ravg_window))
+ p->ravg.sum = walt_ravg_window;
+}
+
+/*
+ * Account cpu demand of task and/or update task's cpu demand history
+ *
+ * ms = p->ravg.mark_start;
+ * wc = wallclock
+ * ws = rq->window_start
+ *
+ * Three possibilities:
+ *
+ * a) Task event is contained within one window.
+ * window_start < mark_start < wallclock
+ *
+ * ws ms wc
+ * | | |
+ * V V V
+ * |---------------|
+ *
+ * In this case, p->ravg.sum is updated *iff* event is appropriate
+ * (ex: event == PUT_PREV_TASK)
+ *
+ * b) Task event spans two windows.
+ * mark_start < window_start < wallclock
+ *
+ * ms ws wc
+ * | | |
+ * V V V
+ * -----|-------------------
+ *
+ * In this case, p->ravg.sum is updated with (ws - ms) *iff* event
+ * is appropriate, then a new window sample is recorded followed
+ * by p->ravg.sum being set to (wc - ws) *iff* event is appropriate.
+ *
+ * c) Task event spans more than two windows.
+ *
+ * ms ws_tmp ws wc
+ * | | | |
+ * V V V V
+ * ---|-------|-------|-------|-------|------
+ * | |
+ * |<------ nr_full_windows ------>|
+ *
+ * In this case, p->ravg.sum is updated with (ws_tmp - ms) first *iff*
+ * event is appropriate, window sample of p->ravg.sum is recorded,
+ * 'nr_full_window' samples of window_size is also recorded *iff*
+ * event is appropriate and finally p->ravg.sum is set to (wc - ws)
+ * *iff* event is appropriate.
+ *
+ * IMPORTANT : Leave p->ravg.mark_start unchanged, as update_cpu_busy_time()
+ * depends on it!
+ */
+static void update_task_demand(struct task_struct *p, struct rq *rq,
+ int event, u64 wallclock)
+{
+ u64 mark_start = p->ravg.mark_start;
+ u64 delta, window_start = rq->window_start;
+ int new_window, nr_full_windows;
+ u32 window_size = walt_ravg_window;
+
+ new_window = mark_start < window_start;
+ if (!account_busy_for_task_demand(p, event)) {
+ if (new_window)
+ /* If the time accounted isn't being accounted as
+ * busy time, and a new window started, only the
+ * previous window need be closed out with the
+ * pre-existing demand. Multiple windows may have
+ * elapsed, but since empty windows are dropped,
+ * it is not necessary to account those. */
+ update_history(rq, p, p->ravg.sum, 1, event);
+ return;
+ }
+
+ if (!new_window) {
+ /* The simple case - busy time contained within the existing
+ * window. */
+ add_to_task_demand(rq, p, wallclock - mark_start);
+ return;
+ }
+
+ /* Busy time spans at least two windows. Temporarily rewind
+ * window_start to first window boundary after mark_start. */
+ delta = window_start - mark_start;
+ nr_full_windows = div64_u64(delta, window_size);
+ window_start -= (u64)nr_full_windows * (u64)window_size;
+
+ /* Process (window_start - mark_start) first */
+ add_to_task_demand(rq, p, window_start - mark_start);
+
+ /* Push new sample(s) into task's demand history */
+ update_history(rq, p, p->ravg.sum, 1, event);
+ if (nr_full_windows)
+ update_history(rq, p, scale_exec_time(window_size, rq),
+ nr_full_windows, event);
+
+ /* Roll window_start back to current to process any remainder
+ * in current window. */
+ window_start += (u64)nr_full_windows * (u64)window_size;
+
+ /* Process (wallclock - window_start) next */
+ mark_start = window_start;
+ add_to_task_demand(rq, p, wallclock - mark_start);
+}
+
+/* Reflect task activity on its demand and cpu's busy time statistics */
+void walt_update_task_ravg(struct task_struct *p, struct rq *rq,
+ int event, u64 wallclock, u64 irqtime)
+{
+ if (walt_disabled || !rq->window_start)
+ return;
+
+ lockdep_assert_held(&rq->lock);
+
+ update_window_start(rq, wallclock);
+
+ if (!p->ravg.mark_start)
+ goto done;
+
+ update_task_demand(p, rq, event, wallclock);
+ update_cpu_busy_time(p, rq, event, wallclock, irqtime);
+
+done:
+ trace_walt_update_task_ravg(p, rq, event, wallclock, irqtime);
+
+ p->ravg.mark_start = wallclock;
+}
+
+unsigned long __weak arch_get_cpu_efficiency(int cpu)
+{
+ return SCHED_LOAD_SCALE;
+}
+
+void walt_init_cpu_efficiency(void)
+{
+ int i, efficiency;
+ unsigned int max = 0, min = UINT_MAX;
+
+ for_each_possible_cpu(i) {
+ efficiency = arch_get_cpu_efficiency(i);
+ cpu_rq(i)->efficiency = efficiency;
+
+ if (efficiency > max)
+ max = efficiency;
+ if (efficiency < min)
+ min = efficiency;
+ }
+
+ if (max)
+ max_possible_efficiency = max;
+
+ if (min)
+ min_possible_efficiency = min;
+}
+
+static void reset_task_stats(struct task_struct *p)
+{
+ u32 sum = 0;
+
+ if (exiting_task(p))
+ sum = EXITING_TASK_MARKER;
+
+ memset(&p->ravg, 0, sizeof(struct ravg));
+ /* Retain EXITING_TASK marker */
+ p->ravg.sum_history[0] = sum;
+}
+
+void walt_mark_task_starting(struct task_struct *p)
+{
+ u64 wallclock;
+ struct rq *rq = task_rq(p);
+
+ if (!rq->window_start) {
+ reset_task_stats(p);
+ return;
+ }
+
+ wallclock = walt_ktime_clock();
+ p->ravg.mark_start = wallclock;
+}
+
+void walt_set_window_start(struct rq *rq)
+{
+ int cpu = cpu_of(rq);
+ struct rq *sync_rq = cpu_rq(sync_cpu);
+
+ if (rq->window_start)
+ return;
+
+ if (cpu == sync_cpu) {
+ rq->window_start = walt_ktime_clock();
+ } else {
+ raw_spin_unlock(&rq->lock);
+ double_rq_lock(rq, sync_rq);
+ rq->window_start = cpu_rq(sync_cpu)->window_start;
+ rq->curr_runnable_sum = rq->prev_runnable_sum = 0;
+ raw_spin_unlock(&sync_rq->lock);
+ }
+
+ rq->curr->ravg.mark_start = rq->window_start;
+}
+
+void walt_migrate_sync_cpu(int cpu)
+{
+ if (cpu == sync_cpu)
+ sync_cpu = smp_processor_id();
+}
+
+void walt_fixup_busy_time(struct task_struct *p, int new_cpu)
+{
+ struct rq *src_rq = task_rq(p);
+ struct rq *dest_rq = cpu_rq(new_cpu);
+ u64 wallclock;
+
+ if (!p->on_rq && p->state != TASK_WAKING)
+ return;
+
+ if (exiting_task(p)) {
+ return;
+ }
+
+ if (p->state == TASK_WAKING)
+ double_rq_lock(src_rq, dest_rq);
+
+ wallclock = walt_ktime_clock();
+
+ walt_update_task_ravg(task_rq(p)->curr, task_rq(p),
+ TASK_UPDATE, wallclock, 0);
+ walt_update_task_ravg(dest_rq->curr, dest_rq,
+ TASK_UPDATE, wallclock, 0);
+
+ walt_update_task_ravg(p, task_rq(p), TASK_MIGRATE, wallclock, 0);
+
+ if (p->ravg.curr_window) {
+ src_rq->curr_runnable_sum -= p->ravg.curr_window;
+ dest_rq->curr_runnable_sum += p->ravg.curr_window;
+ }
+
+ if (p->ravg.prev_window) {
+ src_rq->prev_runnable_sum -= p->ravg.prev_window;
+ dest_rq->prev_runnable_sum += p->ravg.prev_window;
+ }
+
+ if ((s64)src_rq->prev_runnable_sum < 0) {
+ src_rq->prev_runnable_sum = 0;
+ WARN_ON(1);
+ }
+ if ((s64)src_rq->curr_runnable_sum < 0) {
+ src_rq->curr_runnable_sum = 0;
+ WARN_ON(1);
+ }
+
+ trace_walt_migration_update_sum(src_rq, p);
+ trace_walt_migration_update_sum(dest_rq, p);
+
+ if (p->state == TASK_WAKING)
+ double_rq_unlock(src_rq, dest_rq);
+}
+
+/* Keep track of max/min capacity possible across CPUs "currently" */
+static void __update_min_max_capacity(void)
+{
+ int i;
+ int max = 0, min = INT_MAX;
+
+ for_each_online_cpu(i) {
+ if (cpu_rq(i)->capacity > max)
+ max = cpu_rq(i)->capacity;
+ if (cpu_rq(i)->capacity < min)
+ min = cpu_rq(i)->capacity;
+ }
+
+ max_capacity = max;
+ min_capacity = min;
+}
+
+static void update_min_max_capacity(void)
+{
+ unsigned long flags;
+ int i;
+
+ local_irq_save(flags);
+ for_each_possible_cpu(i)
+ raw_spin_lock(&cpu_rq(i)->lock);
+
+ __update_min_max_capacity();
+
+ for_each_possible_cpu(i)
+ raw_spin_unlock(&cpu_rq(i)->lock);
+ local_irq_restore(flags);
+}
+
+/*
+ * Return 'capacity' of a cpu in reference to "least" efficient cpu, such that
+ * least efficient cpu gets capacity of 1024
+ */
+static unsigned long capacity_scale_cpu_efficiency(int cpu)
+{
+ return (1024 * cpu_rq(cpu)->efficiency) / min_possible_efficiency;
+}
+
+/*
+ * Return 'capacity' of a cpu in reference to cpu with lowest max_freq
+ * (min_max_freq), such that one with lowest max_freq gets capacity of 1024.
+ */
+static unsigned long capacity_scale_cpu_freq(int cpu)
+{
+ return (1024 * cpu_rq(cpu)->max_freq) / min_max_freq;
+}
+
+/*
+ * Return load_scale_factor of a cpu in reference to "most" efficient cpu, so
+ * that "most" efficient cpu gets a load_scale_factor of 1
+ */
+static unsigned long load_scale_cpu_efficiency(int cpu)
+{
+ return DIV_ROUND_UP(1024 * max_possible_efficiency,
+ cpu_rq(cpu)->efficiency);
+}
+
+/*
+ * Return load_scale_factor of a cpu in reference to cpu with best max_freq
+ * (max_possible_freq), so that one with best max_freq gets a load_scale_factor
+ * of 1.
+ */
+static unsigned long load_scale_cpu_freq(int cpu)
+{
+ return DIV_ROUND_UP(1024 * max_possible_freq, cpu_rq(cpu)->max_freq);
+}
+
+static int compute_capacity(int cpu)
+{
+ int capacity = 1024;
+
+ capacity *= capacity_scale_cpu_efficiency(cpu);
+ capacity >>= 10;
+
+ capacity *= capacity_scale_cpu_freq(cpu);
+ capacity >>= 10;
+
+ return capacity;
+}
+
+static int compute_load_scale_factor(int cpu)
+{
+ int load_scale = 1024;
+
+ /*
+ * load_scale_factor accounts for the fact that task load
+ * is in reference to "best" performing cpu. Task's load will need to be
+ * scaled (up) by a factor to determine suitability to be placed on a
+ * (little) cpu.
+ */
+ load_scale *= load_scale_cpu_efficiency(cpu);
+ load_scale >>= 10;
+
+ load_scale *= load_scale_cpu_freq(cpu);
+ load_scale >>= 10;
+
+ return load_scale;
+}
+
+static int cpufreq_notifier_policy(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct cpufreq_policy *policy = (struct cpufreq_policy *)data;
+ int i, update_max = 0;
+ u64 highest_mpc = 0, highest_mplsf = 0;
+ const struct cpumask *cpus = policy->related_cpus;
+ unsigned int orig_min_max_freq = min_max_freq;
+ unsigned int orig_max_possible_freq = max_possible_freq;
+ /* Initialized to policy->max in case policy->related_cpus is empty! */
+ unsigned int orig_max_freq = policy->max;
+
+ if (val != CPUFREQ_NOTIFY && val != CPUFREQ_REMOVE_POLICY &&
+ val != CPUFREQ_CREATE_POLICY)
+ return 0;
+
+ if (val == CPUFREQ_REMOVE_POLICY || val == CPUFREQ_CREATE_POLICY) {
+ update_min_max_capacity();
+ return 0;
+ }
+
+ for_each_cpu(i, policy->related_cpus) {
+ cpumask_copy(&cpu_rq(i)->freq_domain_cpumask,
+ policy->related_cpus);
+ orig_max_freq = cpu_rq(i)->max_freq;
+ cpu_rq(i)->min_freq = policy->min;
+ cpu_rq(i)->max_freq = policy->max;
+ cpu_rq(i)->cur_freq = policy->cur;
+ cpu_rq(i)->max_possible_freq = policy->cpuinfo.max_freq;
+ }
+
+ max_possible_freq = max(max_possible_freq, policy->cpuinfo.max_freq);
+ if (min_max_freq == 1)
+ min_max_freq = UINT_MAX;
+ min_max_freq = min(min_max_freq, policy->cpuinfo.max_freq);
+ BUG_ON(!min_max_freq);
+ BUG_ON(!policy->max);
+
+ /* Changes to policy other than max_freq don't require any updates */
+ if (orig_max_freq == policy->max)
+ return 0;
+
+ /*
+ * A changed min_max_freq or max_possible_freq (possible during bootup)
+ * needs to trigger re-computation of load_scale_factor and capacity for
+ * all possible cpus (even those offline). It also needs to trigger
+ * re-computation of nr_big_task count on all online cpus.
+ *
+ * A changed rq->max_freq otoh needs to trigger re-computation of
+ * load_scale_factor and capacity for just the cluster of cpus involved.
+ * Since small task definition depends on max_load_scale_factor, a
+ * changed load_scale_factor of one cluster could influence
+ * classification of tasks in another cluster. Hence a changed
+ * rq->max_freq will need to trigger re-computation of nr_big_task
+ * count on all online cpus.
+ *
+ * While it should be sufficient for nr_big_tasks to be
+ * re-computed for only online cpus, we have inadequate context
+ * information here (in policy notifier) with regard to hotplug-safety
+ * context in which notification is issued. As a result, we can't use
+ * get_online_cpus() here, as it can lead to deadlock. Until cpufreq is
+ * fixed up to issue notification always in hotplug-safe context,
+ * re-compute nr_big_task for all possible cpus.
+ */
+
+ if (orig_min_max_freq != min_max_freq ||
+ orig_max_possible_freq != max_possible_freq) {
+ cpus = cpu_possible_mask;
+ update_max = 1;
+ }
+
+ /*
+ * Changed load_scale_factor can trigger reclassification of tasks as
+ * big or small. Make this change "atomic" so that tasks are accounted
+ * properly due to changed load_scale_factor
+ */
+ for_each_cpu(i, cpus) {
+ struct rq *rq = cpu_rq(i);
+
+ rq->capacity = compute_capacity(i);
+ rq->load_scale_factor = compute_load_scale_factor(i);
+
+ if (update_max) {
+ u64 mpc, mplsf;
+
+ mpc = div_u64(((u64) rq->capacity) *
+ rq->max_possible_freq, rq->max_freq);
+ rq->max_possible_capacity = (int) mpc;
+
+ mplsf = div_u64(((u64) rq->load_scale_factor) *
+ rq->max_possible_freq, rq->max_freq);
+
+ if (mpc > highest_mpc) {
+ highest_mpc = mpc;
+ cpumask_clear(&mpc_mask);
+ cpumask_set_cpu(i, &mpc_mask);
+ } else if (mpc == highest_mpc) {
+ cpumask_set_cpu(i, &mpc_mask);
+ }
+
+ if (mplsf > highest_mplsf)
+ highest_mplsf = mplsf;
+ }
+ }
+
+ if (update_max) {
+ max_possible_capacity = highest_mpc;
+ max_load_scale_factor = highest_mplsf;
+ }
+
+ __update_min_max_capacity();
+
+ return 0;
+}
+
+static int cpufreq_notifier_trans(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct cpufreq_freqs *freq = (struct cpufreq_freqs *)data;
+ unsigned int cpu = freq->cpu, new_freq = freq->new;
+ unsigned long flags;
+ int i;
+
+ if (val != CPUFREQ_POSTCHANGE)
+ return 0;
+
+ BUG_ON(!new_freq);
+
+ if (cpu_rq(cpu)->cur_freq == new_freq)
+ return 0;
+
+ for_each_cpu(i, &cpu_rq(cpu)->freq_domain_cpumask) {
+ struct rq *rq = cpu_rq(i);
+
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ walt_update_task_ravg(rq->curr, rq, TASK_UPDATE,
+ walt_ktime_clock(), 0);
+ rq->cur_freq = new_freq;
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+ }
+
+ return 0;
+}
+
+static struct notifier_block notifier_policy_block = {
+ .notifier_call = cpufreq_notifier_policy
+};
+
+static struct notifier_block notifier_trans_block = {
+ .notifier_call = cpufreq_notifier_trans
+};
+
+static int register_sched_callback(void)
+{
+ int ret;
+
+ ret = cpufreq_register_notifier(&notifier_policy_block,
+ CPUFREQ_POLICY_NOTIFIER);
+
+ if (!ret)
+ ret = cpufreq_register_notifier(&notifier_trans_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+
+ return 0;
+}
+
+/*
+ * cpufreq callbacks can be registered at core_initcall or later time.
+ * Any registration done prior to that is "forgotten" by cpufreq. See
+ * initialization of variable init_cpufreq_transition_notifier_list_called
+ * for further information.
+ */
+core_initcall(register_sched_callback);
+
+void walt_init_new_task_load(struct task_struct *p)
+{
+ int i;
+ u32 init_load_windows =
+ div64_u64((u64)sysctl_sched_walt_init_task_load_pct *
+ (u64)walt_ravg_window, 100);
+ u32 init_load_pct = current->init_load_pct;
+
+ p->init_load_pct = 0;
+ memset(&p->ravg, 0, sizeof(struct ravg));
+
+ if (init_load_pct) {
+ init_load_windows = div64_u64((u64)init_load_pct *
+ (u64)walt_ravg_window, 100);
+ }
+
+ p->ravg.demand = init_load_windows;
+ for (i = 0; i < RAVG_HIST_SIZE_MAX; ++i)
+ p->ravg.sum_history[i] = init_load_windows;
+}
diff --git a/kernel/sched/walt.h b/kernel/sched/walt.h
new file mode 100644
index 000000000000..cabc193a683d
--- /dev/null
+++ b/kernel/sched/walt.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __WALT_H
+#define __WALT_H
+
+#ifdef CONFIG_SCHED_WALT
+
+void walt_update_task_ravg(struct task_struct *p, struct rq *rq, int event,
+ u64 wallclock, u64 irqtime);
+void walt_inc_cumulative_runnable_avg(struct rq *rq, struct task_struct *p);
+void walt_dec_cumulative_runnable_avg(struct rq *rq, struct task_struct *p);
+void walt_inc_cfs_cumulative_runnable_avg(struct cfs_rq *rq,
+ struct task_struct *p);
+void walt_dec_cfs_cumulative_runnable_avg(struct cfs_rq *rq,
+ struct task_struct *p);
+void walt_fixup_busy_time(struct task_struct *p, int new_cpu);
+void walt_init_new_task_load(struct task_struct *p);
+void walt_mark_task_starting(struct task_struct *p);
+void walt_set_window_start(struct rq *rq);
+void walt_migrate_sync_cpu(int cpu);
+void walt_init_cpu_efficiency(void);
+u64 walt_ktime_clock(void);
+
+#else /* CONFIG_SCHED_WALT */
+
+static inline void walt_update_task_ravg(struct task_struct *p, struct rq *rq,
+ int event, u64 wallclock, u64 irqtime) { }
+static inline void walt_inc_cumulative_runnable_avg(struct rq *rq, struct task_struct *p) { }
+static inline void walt_dec_cumulative_runnable_avg(struct rq *rq, struct task_struct *p) { }
+static inline void walt_inc_cfs_cumulative_runnable_avg(struct cfs_rq *rq,
+ struct task_struct *p) { }
+static inline void walt_dec_cfs_cumulative_runnable_avg(struct cfs_rq *rq,
+ struct task_struct *p) { }
+static inline void walt_fixup_busy_time(struct task_struct *p, int new_cpu) { }
+static inline void walt_init_new_task_load(struct task_struct *p) { }
+static inline void walt_mark_task_starting(struct task_struct *p) { }
+static inline void walt_set_window_start(struct rq *rq) { }
+static inline void walt_migrate_sync_cpu(int cpu) { }
+static inline void walt_init_cpu_efficiency(void) { }
+static inline u64 walt_ktime_clock(void) { return 0; }
+
+#endif /* CONFIG_SCHED_WALT */
+
+extern unsigned int walt_disabled;
+
+#endif
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index dd46f370b73a..e2d9953822be 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -311,6 +311,29 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
+#ifdef CONFIG_SCHED_WALT
+ {
+ .procname = "sched_use_walt_cpu_util",
+ .data = &sysctl_sched_use_walt_cpu_util,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "sched_use_walt_task_util",
+ .data = &sysctl_sched_use_walt_task_util,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "sched_walt_init_task_load_pct",
+ .data = &sysctl_sched_walt_init_task_load_pct,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+#endif
{
.procname = "sched_sync_hint_enable",
.data = &sysctl_sched_sync_hint_enable,
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-16 18:58:25 +0000