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Message-Id: <c921a362c78e1324f8ebc5aaa12f53e309c5a8a2.1607400596.git.viresh.kumar@linaro.org>
Date: Tue, 8 Dec 2020 09:46:55 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Ingo Molnar <mingo@...hat.com>,
Peter Zijlstra <peterz@...radead.org>,
Vincent Guittot <vincent.guittot@...aro.org>,
Juri Lelli <juri.lelli@...hat.com>,
Dietmar Eggemann <dietmar.eggemann@....com>,
Steven Rostedt <rostedt@...dmis.org>,
Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
Daniel Bristot de Oliveira <bristot@...hat.com>,
"Rafael J. Wysocki" <rjw@...ysocki.net>,
Viresh Kumar <viresh.kumar@...aro.org>
Cc: linux-kernel@...r.kernel.org, Quentin Perret <qperret@...gle.com>,
Lukasz Luba <lukasz.luba@....com>,
"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
linux-pm@...r.kernel.org
Subject: [PATCH V5 1/3] sched/core: Move schedutil_cpu_util() to core.c
There is nothing schedutil specific in schedutil_cpu_util(), move it to
core.c and define it only for CONFIG_SMP.
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
kernel/sched/core.c | 108 +++++++++++++++++++++++++++++++
kernel/sched/cpufreq_schedutil.c | 106 ------------------------------
kernel/sched/sched.h | 12 +---
3 files changed, 109 insertions(+), 117 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d2003a7d5ab5..b81265aec4a0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5117,6 +5117,114 @@ struct task_struct *idle_task(int cpu)
return cpu_rq(cpu)->idle;
}
+#ifdef CONFIG_SMP
+/*
+ * This function computes an effective utilization for the given CPU, to be
+ * used for frequency selection given the linear relation: f = u * f_max.
+ *
+ * The scheduler tracks the following metrics:
+ *
+ * cpu_util_{cfs,rt,dl,irq}()
+ * cpu_bw_dl()
+ *
+ * Where the cfs,rt and dl util numbers are tracked with the same metric and
+ * synchronized windows and are thus directly comparable.
+ *
+ * The cfs,rt,dl utilization are the running times measured with rq->clock_task
+ * which excludes things like IRQ and steal-time. These latter are then accrued
+ * in the irq utilization.
+ *
+ * The DL bandwidth number otoh is not a measured metric but a value computed
+ * based on the task model parameters and gives the minimal utilization
+ * required to meet deadlines.
+ */
+unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
+ unsigned long max, enum schedutil_type type,
+ struct task_struct *p)
+{
+ unsigned long dl_util, util, irq;
+ struct rq *rq = cpu_rq(cpu);
+
+ if (!uclamp_is_used() &&
+ type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) {
+ return max;
+ }
+
+ /*
+ * Early check to see if IRQ/steal time saturates the CPU, can be
+ * because of inaccuracies in how we track these -- see
+ * update_irq_load_avg().
+ */
+ irq = cpu_util_irq(rq);
+ if (unlikely(irq >= max))
+ return max;
+
+ /*
+ * Because the time spend on RT/DL tasks is visible as 'lost' time to
+ * CFS tasks and we use the same metric to track the effective
+ * utilization (PELT windows are synchronized) we can directly add them
+ * to obtain the CPU's actual utilization.
+ *
+ * CFS and RT utilization can be boosted or capped, depending on
+ * utilization clamp constraints requested by currently RUNNABLE
+ * tasks.
+ * When there are no CFS RUNNABLE tasks, clamps are released and
+ * frequency will be gracefully reduced with the utilization decay.
+ */
+ util = util_cfs + cpu_util_rt(rq);
+ if (type == FREQUENCY_UTIL)
+ util = uclamp_rq_util_with(rq, util, p);
+
+ dl_util = cpu_util_dl(rq);
+
+ /*
+ * 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 + 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
+ * need to scale the task numbers:
+ *
+ * max - irq
+ * U' = irq + --------- * U
+ * max
+ */
+ util = scale_irq_capacity(util, irq, max);
+ util += irq;
+
+ /*
+ * Bandwidth required by DEADLINE must always be granted while, for
+ * FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism
+ * to gracefully reduce the frequency when no tasks show up for longer
+ * periods of time.
+ *
+ * Ideally we would like to set bw_dl as min/guaranteed freq and util +
+ * bw_dl as requested freq. However, cpufreq is not yet ready for such
+ * an interface. So, we only do the latter for now.
+ */
+ if (type == FREQUENCY_UTIL)
+ util += cpu_bw_dl(rq);
+
+ return min(max, util);
+}
+#endif /* CONFIG_SMP */
+
/**
* find_process_by_pid - find a process with a matching PID value.
* @pid: the pid in question.
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index e254745a82cb..2d44befb322b 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -169,112 +169,6 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy,
return cpufreq_driver_resolve_freq(policy, freq);
}
-/*
- * This function computes an effective utilization for the given CPU, to be
- * used for frequency selection given the linear relation: f = u * f_max.
- *
- * The scheduler tracks the following metrics:
- *
- * cpu_util_{cfs,rt,dl,irq}()
- * cpu_bw_dl()
- *
- * Where the cfs,rt and dl util numbers are tracked with the same metric and
- * synchronized windows and are thus directly comparable.
- *
- * The cfs,rt,dl utilization are the running times measured with rq->clock_task
- * which excludes things like IRQ and steal-time. These latter are then accrued
- * in the irq utilization.
- *
- * The DL bandwidth number otoh is not a measured metric but a value computed
- * based on the task model parameters and gives the minimal utilization
- * required to meet deadlines.
- */
-unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
- unsigned long max, enum schedutil_type type,
- struct task_struct *p)
-{
- unsigned long dl_util, util, irq;
- struct rq *rq = cpu_rq(cpu);
-
- if (!uclamp_is_used() &&
- type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) {
- return max;
- }
-
- /*
- * Early check to see if IRQ/steal time saturates the CPU, can be
- * because of inaccuracies in how we track these -- see
- * update_irq_load_avg().
- */
- irq = cpu_util_irq(rq);
- if (unlikely(irq >= max))
- return max;
-
- /*
- * Because the time spend on RT/DL tasks is visible as 'lost' time to
- * CFS tasks and we use the same metric to track the effective
- * utilization (PELT windows are synchronized) we can directly add them
- * to obtain the CPU's actual utilization.
- *
- * CFS and RT utilization can be boosted or capped, depending on
- * utilization clamp constraints requested by currently RUNNABLE
- * tasks.
- * When there are no CFS RUNNABLE tasks, clamps are released and
- * frequency will be gracefully reduced with the utilization decay.
- */
- util = util_cfs + cpu_util_rt(rq);
- if (type == FREQUENCY_UTIL)
- util = uclamp_rq_util_with(rq, util, p);
-
- dl_util = cpu_util_dl(rq);
-
- /*
- * 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 + 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
- * need to scale the task numbers:
- *
- * max - irq
- * U' = irq + --------- * U
- * max
- */
- util = scale_irq_capacity(util, irq, max);
- util += irq;
-
- /*
- * Bandwidth required by DEADLINE must always be granted while, for
- * FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism
- * to gracefully reduce the frequency when no tasks show up for longer
- * periods of time.
- *
- * Ideally we would like to set bw_dl as min/guaranteed freq and util +
- * bw_dl as requested freq. However, cpufreq is not yet ready for such
- * an interface. So, we only do the latter for now.
- */
- 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);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index df80bfcea92e..0db6bcf0881f 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2484,7 +2484,6 @@ static inline unsigned long capacity_orig_of(int cpu)
{
return cpu_rq(cpu)->cpu_capacity_orig;
}
-#endif
/**
* enum schedutil_type - CPU utilization type
@@ -2501,8 +2500,6 @@ enum schedutil_type {
ENERGY_UTIL,
};
-#ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
-
unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
unsigned long max, enum schedutil_type type,
struct task_struct *p);
@@ -2533,14 +2530,7 @@ 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_cpu_util(int cpu, unsigned long util_cfs,
- unsigned long max, enum schedutil_type type,
- struct task_struct *p)
-{
- return 0;
-}
-#endif /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
+#endif
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
static inline unsigned long cpu_util_irq(struct rq *rq)
--
2.25.0.rc1.19.g042ed3e048af
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