Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8544ede9 authored by Miguel de Dios's avatar Miguel de Dios Committed by Harshit Jain
Browse files

kernel: sched: Mitigate non-boosted tasks preempting boosted tasks 



Currently when a boosted task is scheduled we use prefer_idle to try and
get it to an idle core. Once it's scheduled, there is a possibility we
can schedule a non-boosted task on the same core where the boosted task
is running on. This change aims to mitigate that possibility by checking
if the core we're targeting has a boosted task and if so, use the next
best idle core instead.

Bug: 131626264
Bug: 144961676
Change-Id: I3d321e1c71f96526f55f7f3a56e32db411311aa2
Signed-off-by: default avatarMiguel de Dios <migueldedios@google.com>
Signed-off-by: default avatarJimmy Shiu <jimmyshiu@google.com>
Signed-off-by: default avatarminaripenguin <minaripenguin@users.noreply.github.com>
parent 334ba2f8

kernel/sched/fair.c

+8 −0
Original line number Diff line number Diff line
@@ -7464,6 +7464,7 @@ static inline int find_best_target(struct task_struct *p, int *backup_cpu, 
	bool next_group_higher_cap = false;

	int isolated_candidate = -1;

	struct root_domain *rd;

	struct task_struct *curr_tsk;



	*backup_cpu = -1;
@@ -7852,6 +7853,13 @@ static inline int find_best_target(struct task_struct *p, int *backup_cpu, 
	 *   b) IDLE CPU: best_idle_cpu

	 */



    if (target_cpu != -1 && !idle_cpu(target_cpu) &&

			best_idle_cpu != -1) {

		curr_tsk = READ_ONCE(cpu_rq(target_cpu)->curr);

		if (curr_tsk && schedtune_task_boost_rcu_locked(curr_tsk))

			target_cpu = best_idle_cpu;

	}



	if (prefer_idle && (best_idle_cpu != -1)) {

		trace_sched_find_best_target(p, prefer_idle, min_util, cpu,

					     best_idle_cpu, best_active_cpu,

kernel/sched/tune.c

+18 −0
Original line number Diff line number Diff line
@@ -592,6 +592,24 @@ int schedtune_task_boost(struct task_struct *p) 
	return task_boost;

}



/*  The same as schedtune_task_boost except assuming the caller has the rcu read

 *  lock.

 */

int schedtune_task_boost_rcu_locked(struct task_struct *p)

{

	struct schedtune *st;

	int task_boost;



	if (unlikely(!schedtune_initialized))

		return 0;



	/* Get task boost value */

	st = task_schedtune(p);

	task_boost = st->boost;



	return task_boost;

}



int schedtune_prefer_idle(struct task_struct *p)

{

	struct schedtune *st;

kernel/sched/tune.h

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ struct target_nrg { 


int schedtune_cpu_boost(int cpu);

int schedtune_task_boost(struct task_struct *tsk);

int schedtune_task_boost_rcu_locked(struct task_struct *tsk);



int schedtune_prefer_idle(struct task_struct *tsk);