sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c (5d871a63) · Commits · git / linux-nf

kernel/sched/fair.c

+99 −0

Original line number	Diff line number	Diff line
		@@ -8084,6 +8084,105 @@ static unsigned long cpu_util_without(int cpu, struct task_struct *p)
		return cpu_util(cpu, p, -1, 0);
		}

		/*
		* 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 effective_cpu_util(int cpu, unsigned long util_cfs,
		unsigned long *min,
		unsigned long *max)
		{
		unsigned long util, irq, scale;
		struct rq *rq = cpu_rq(cpu);

		scale = arch_scale_cpu_capacity(cpu);

		/*
		* 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 >= scale)) {
		if (min)
		*min = scale;
		if (max)
		*max = scale;
		return scale;
		}

		if (min) {
		/*
		* The minimum utilization returns the highest level between:
		* - the computed DL bandwidth needed with the IRQ pressure which
		* steals time to the deadline task.
		* - The minimum performance requirement for CFS and/or RT.
		*/
		*min = max(irq + cpu_bw_dl(rq), uclamp_rq_get(rq, UCLAMP_MIN));

		/*
		* When an RT task is runnable and uclamp is not used, we must
		* ensure that the task will run at maximum compute capacity.
		*/
		if (!uclamp_is_used() && rt_rq_is_runnable(&rq->rt))
		min = max(min, scale);
		}

		/*
		* 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.
		*/
		util = util_cfs + cpu_util_rt(rq);
		util += cpu_util_dl(rq);

		/*
		* The maximum hint is a soft bandwidth requirement, which can be lower
		* than the actual utilization because of uclamp_max requirements.
		*/
		if (max)
		*max = min(scale, uclamp_rq_get(rq, UCLAMP_MAX));

		if (util >= scale)
		return scale;

		/*
		* 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, scale);
		util += irq;

		return min(scale, util);
		}

		unsigned long sched_cpu_util(int cpu)
		{
		return effective_cpu_util(cpu, cpu_util_cfs(cpu), NULL, NULL);
		}

		/*
		* energy_env - Utilization landscape for energy estimation.
		* @task_busy_time: Utilization contribution by the task for which we test the

kernel/sched/syscalls.c

+0 −101

Original line number	Diff line number	Diff line
		@@ -258,107 +258,6 @@ int sched_core_idle_cpu(int cpu)

		#endif

		#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 effective_cpu_util(int cpu, unsigned long util_cfs,
		unsigned long *min,
		unsigned long *max)
		{
		unsigned long util, irq, scale;
		struct rq *rq = cpu_rq(cpu);

		scale = arch_scale_cpu_capacity(cpu);

		/*
		* 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 >= scale)) {
		if (min)
		*min = scale;
		if (max)
		*max = scale;
		return scale;
		}

		if (min) {
		/*
		* The minimum utilization returns the highest level between:
		* - the computed DL bandwidth needed with the IRQ pressure which
		* steals time to the deadline task.
		* - The minimum performance requirement for CFS and/or RT.
		*/
		*min = max(irq + cpu_bw_dl(rq), uclamp_rq_get(rq, UCLAMP_MIN));

		/*
		* When an RT task is runnable and uclamp is not used, we must
		* ensure that the task will run at maximum compute capacity.
		*/
		if (!uclamp_is_used() && rt_rq_is_runnable(&rq->rt))
		min = max(min, scale);
		}

		/*
		* 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.
		*/
		util = util_cfs + cpu_util_rt(rq);
		util += cpu_util_dl(rq);

		/*
		* The maximum hint is a soft bandwidth requirement, which can be lower
		* than the actual utilization because of uclamp_max requirements.
		*/
		if (max)
		*max = min(scale, uclamp_rq_get(rq, UCLAMP_MAX));

		if (util >= scale)
		return scale;

		/*
		* 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, scale);
		util += irq;

		return min(scale, util);
		}

		unsigned long sched_cpu_util(int cpu)
		{
		return effective_cpu_util(cpu, cpu_util_cfs(cpu), NULL, NULL);
		}
		#endif /* CONFIG_SMP */

		/**
		* find_process_by_pid - find a process with a matching PID value.
		* @pid: the pid in question.