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From:   Ionela Voinescu <ionela.voinescu@arm.com>
To:     mingo@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org,
        catalin.marinas@arm.com, will@kernel.org, rjw@rjwysocki.net,
        viresh.kumar@linaro.org
Cc:     dietmar.eggemann@arm.com, qperret@google.com,
        valentin.schneider@arm.com, linux-pm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        ionela.voinescu@arm.com
Subject: [PATCH 1/3] sched/topology,schedutil: wrap sched domains rebuild
Date:   Thu, 24 Sep 2020 13:39:35 +0100
Message-Id: <20200924123937.20938-2-ionela.voinescu@arm.com>
In-Reply-To: <20200924123937.20938-1-ionela.voinescu@arm.com>
References: <20200924123937.20938-1-ionela.voinescu@arm.com>
Precedence: bulk

Add the rebuild_sched_domains_energy() function to wrap the functionality
that rebuilds the scheduling domains if any of the Energy Aware Scheduling
(EAS) initialisation conditions change. This functionality is used when
schedutil is added or removed or when EAS is enabled or disabled
through the sched_energy_aware sysctl.

Therefore, create a single function that is used in both these cases and
that can be later reused.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
---
 include/linux/sched/topology.h   |  1 +
 kernel/sched/cpufreq_schedutil.c |  9 +--------
 kernel/sched/topology.c          | 19 ++++++++++++-------
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
index 9ef7bf686a9f..f122115d6c54 100644
--- a/include/linux/sched/topology.h
+++ b/include/linux/sched/topology.h
@@ -158,6 +158,7 @@ static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
 	return to_cpumask(sd->span);
 }
 
+extern void rebuild_sched_domains_energy(void);
 extern void partition_sched_domains_locked(int ndoms_new,
 					   cpumask_var_t doms_new[],
 					   struct sched_domain_attr *dattr_new);
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index e39008242cf4..0337a9b025e1 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -912,16 +912,9 @@ struct cpufreq_governor *cpufreq_default_governor(void)
 cpufreq_governor_init(schedutil_gov);
 
 #ifdef CONFIG_ENERGY_MODEL
-extern bool sched_energy_update;
-extern struct mutex sched_energy_mutex;
-
 static void rebuild_sd_workfn(struct work_struct *work)
 {
-	mutex_lock(&sched_energy_mutex);
-	sched_energy_update = true;
-	rebuild_sched_domains();
-	sched_energy_update = false;
-	mutex_unlock(&sched_energy_mutex);
+	rebuild_sched_domains_energy();
 }
 static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn);
 
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 55c453d140e9..4073f693e2b5 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -211,6 +211,15 @@ unsigned int sysctl_sched_energy_aware = 1;
 DEFINE_MUTEX(sched_energy_mutex);
 bool sched_energy_update;
 
+void rebuild_sched_domains_energy(void)
+{
+	mutex_lock(&sched_energy_mutex);
+	sched_energy_update = true;
+	rebuild_sched_domains();
+	sched_energy_update = false;
+	mutex_unlock(&sched_energy_mutex);
+}
+
 #ifdef CONFIG_PROC_SYSCTL
 int sched_energy_aware_handler(struct ctl_table *table, int write,
 		void *buffer, size_t *lenp, loff_t *ppos)
@@ -223,13 +232,8 @@ int sched_energy_aware_handler(struct ctl_table *table, int write,
 	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 	if (!ret && write) {
 		state = static_branch_unlikely(&sched_energy_present);
-		if (state != sysctl_sched_energy_aware) {
-			mutex_lock(&sched_energy_mutex);
-			sched_energy_update = 1;
-			rebuild_sched_domains();
-			sched_energy_update = 0;
-			mutex_unlock(&sched_energy_mutex);
-		}
+		if (state != sysctl_sched_energy_aware)
+			rebuild_sched_domains_energy();
 	}
 
 	return ret;
@@ -433,6 +437,7 @@ static bool build_perf_domains(const struct cpumask *cpu_map)
 }
 #else
 static void free_pd(struct perf_domain *pd) { }
+void rebuild_sched_domains_energy(void) { }
 #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL*/
 
 static void free_rootdomain(struct rcu_head *rcu)
-- 
2.17.1