linux-kernel - [tip: sched/core] sched/uclamp: Make select_idle_capacity() use util_fits

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Date:   Fri, 28 Oct 2022 06:42:22 -0000
From:   "tip-bot2 for Qais Yousef" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Qais Yousef <qais.yousef@....com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: sched/core] sched/uclamp: Make select_idle_capacity() use
 util_fits_cpu()

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     b759caa1d9f667b94727b2ad12589cbc4ce13a82
Gitweb:        https://git.kernel.org/tip/b759caa1d9f667b94727b2ad12589cbc4ce13a82
Author:        Qais Yousef <qais.yousef@....com>
AuthorDate:    Thu, 04 Aug 2022 15:36:04 +01:00
Committer:     Peter Zijlstra <peterz@...radead.org>
CommitterDate: Thu, 27 Oct 2022 11:01:18 +02:00

sched/uclamp: Make select_idle_capacity() use util_fits_cpu()

Use the new util_fits_cpu() to ensure migration margin and capacity
pressure are taken into account correctly when uclamp is being used
otherwise we will fail to consider CPUs as fitting in scenarios where
they should.

Fixes: b4c9c9f15649 ("sched/fair: Prefer prev cpu in asymmetric wakeup path")
Signed-off-by: Qais Yousef <qais.yousef@....com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Link: https://lore.kernel.org/r/20220804143609.515789-5-qais.yousef@arm.com
---
 kernel/sched/fair.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c8eb5ff..c877bbf 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6779,21 +6779,23 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool 
 static int
 select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target)
 {
-	unsigned long task_util, best_cap = 0;
+	unsigned long task_util, util_min, util_max, best_cap = 0;
 	int cpu, best_cpu = -1;
 	struct cpumask *cpus;
 
 	cpus = this_cpu_cpumask_var_ptr(select_rq_mask);
 	cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
 
-	task_util = uclamp_task_util(p);
+	task_util = task_util_est(p);
+	util_min = uclamp_eff_value(p, UCLAMP_MIN);
+	util_max = uclamp_eff_value(p, UCLAMP_MAX);
 
 	for_each_cpu_wrap(cpu, cpus, target) {
 		unsigned long cpu_cap = capacity_of(cpu);
 
 		if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu))
 			continue;
-		if (fits_capacity(task_util, cpu_cap))
+		if (util_fits_cpu(task_util, util_min, util_max, cpu))
 			return cpu;
 
 		if (cpu_cap > best_cap) {