Commit 96fd6c65 authored by Tejun Heo's avatar Tejun Heo
Browse files

sched: Factor out update_other_load_avgs() from __update_blocked_others() 



RT, DL, thermal and irq load and utilization metrics need to be decayed and
updated periodically and before consumption to keep the numbers reasonable.
This is currently done from __update_blocked_others() as a part of the fair
class load balance path. Let's factor it out to update_other_load_avgs().
Pure refactor. No functional changes.

This will be used by the new BPF extensible scheduling class to ensure that
the above metrics are properly maintained.

v2: Refreshed on top of tip:sched/core.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarDavid Vernet <dvernet@meta.com>
parent 4f9c7ca8

kernel/sched/fair.c

+3 −13
Original line number Diff line number Diff line
@@ -9352,28 +9352,18 @@ static inline void update_blocked_load_status(struct rq *rq, bool has_blocked) { 


static bool __update_blocked_others(struct rq *rq, bool *done)

{

	const struct sched_class *curr_class;

	u64 now = rq_clock_pelt(rq);

	unsigned long hw_pressure;

	bool decayed;

	bool updated;



	/*

	 * update_load_avg() can call cpufreq_update_util(). Make sure that RT,

	 * DL and IRQ signals have been updated before updating CFS.

	 */

	curr_class = rq->curr->sched_class;



	hw_pressure = arch_scale_hw_pressure(cpu_of(rq));



	decayed = update_rt_rq_load_avg(now, rq, curr_class == &rt_sched_class) |

		  update_dl_rq_load_avg(now, rq, curr_class == &dl_sched_class) |

		  update_hw_load_avg(now, rq, hw_pressure) |

		  update_irq_load_avg(rq, 0);

	updated = update_other_load_avgs(rq);



	if (others_have_blocked(rq))

		*done = false;



	return decayed;

	return updated;

}



#ifdef CONFIG_FAIR_GROUP_SCHED

kernel/sched/sched.h

+4 −0
Original line number Diff line number Diff line
@@ -3074,6 +3074,8 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) { } 


#ifdef CONFIG_SMP



bool update_other_load_avgs(struct rq *rq);



unsigned long effective_cpu_util(int cpu, unsigned long util_cfs,

				 unsigned long *min,

				 unsigned long *max);
@@ -3117,6 +3119,8 @@ static inline unsigned long cpu_util_rt(struct rq *rq) 
	return READ_ONCE(rq->avg_rt.util_avg);

}



#else /* !CONFIG_SMP */

static inline bool update_other_load_avgs(struct rq *rq) { return false; }

#endif /* CONFIG_SMP */



#ifdef CONFIG_UCLAMP_TASK

kernel/sched/syscalls.c

+19 −0
Original line number Diff line number Diff line
@@ -259,6 +259,25 @@ int sched_core_idle_cpu(int cpu) 
#endif



#ifdef CONFIG_SMP

/*

 * Load avg and utiliztion metrics need to be updated periodically and before

 * consumption. This function updates the metrics for all subsystems except for

 * the fair class. @rq must be locked and have its clock updated.

 */

bool update_other_load_avgs(struct rq *rq)

{

	u64 now = rq_clock_pelt(rq);

	const struct sched_class *curr_class = rq->curr->sched_class;

	unsigned long hw_pressure = arch_scale_hw_pressure(cpu_of(rq));



	lockdep_assert_rq_held(rq);



	return update_rt_rq_load_avg(now, rq, curr_class == &rt_sched_class) |

		update_dl_rq_load_avg(now, rq, curr_class == &dl_sched_class) |

		update_hw_load_avg(now, rq, hw_pressure) |

		update_irq_load_avg(rq, 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.