linux-kernel - [tip: sched/core] sched/fair: Make per-cpu cpumasks static

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Date:   Wed, 03 Aug 2022 17:30:43 -0000
From:   "tip-bot2 for Bing Huang" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Bing Huang <huangbing@...inos.cn>, Ingo Molnar <mingo@...nel.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Vincent Guittot <vincent.guittot@...aro.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: sched/core] sched/fair: Make per-cpu cpumasks static

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

Commit-ID:     18c31c9711a90b48a77b78afb65012d9feec444c
Gitweb:        https://git.kernel.org/tip/18c31c9711a90b48a77b78afb65012d9feec444c
Author:        Bing Huang <huangbing@...inos.cn>
AuthorDate:    Sat, 23 Jul 2022 05:36:09 +08:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Wed, 03 Aug 2022 19:17:33 +02:00

sched/fair: Make per-cpu cpumasks static

The load_balance_mask and select_rq_mask percpu variables are only used in
kernel/sched/fair.c.

Make them static and move their allocation into init_sched_fair_class().

Replace kzalloc_node() with zalloc_cpumask_var_node() to get rid of the
CONFIG_CPUMASK_OFFSTACK #ifdef and to align with per-cpu cpumask
allocation for RT (local_cpu_mask in init_sched_rt_class()) and DL
class (local_cpu_mask_dl in init_sched_dl_class()).

[ mingo: Tidied up changelog & touched up the code. ]

Signed-off-by: Bing Huang <huangbing@...inos.cn>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@....com>
Reviewed-by: Vincent Guittot <vincent.guittot@...aro.org>
Link: https://lore.kernel.org/r/20220722213609.3901-1-huangbing775@126.com
---
 kernel/sched/core.c | 11 -----------
 kernel/sched/fair.c | 11 +++++++++--
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6785e3b..64c0899 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -9563,9 +9563,6 @@ LIST_HEAD(task_groups);
 static struct kmem_cache *task_group_cache __read_mostly;
 #endif
 
-DECLARE_PER_CPU(cpumask_var_t, load_balance_mask);
-DECLARE_PER_CPU(cpumask_var_t, select_rq_mask);
-
 void __init sched_init(void)
 {
 	unsigned long ptr = 0;
@@ -9609,14 +9606,6 @@ void __init sched_init(void)
 
 #endif /* CONFIG_RT_GROUP_SCHED */
 	}
-#ifdef CONFIG_CPUMASK_OFFSTACK
-	for_each_possible_cpu(i) {
-		per_cpu(load_balance_mask, i) = (cpumask_var_t)kzalloc_node(
-			cpumask_size(), GFP_KERNEL, cpu_to_node(i));
-		per_cpu(select_rq_mask, i) = (cpumask_var_t)kzalloc_node(
-			cpumask_size(), GFP_KERNEL, cpu_to_node(i));
-	}
-#endif /* CONFIG_CPUMASK_OFFSTACK */
 
 	init_rt_bandwidth(&def_rt_bandwidth, global_rt_period(), global_rt_runtime());
 
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d22c5e8..da38865 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5893,8 +5893,8 @@ dequeue_throttle:
 #ifdef CONFIG_SMP
 
 /* Working cpumask for: load_balance, load_balance_newidle. */
-DEFINE_PER_CPU(cpumask_var_t, load_balance_mask);
-DEFINE_PER_CPU(cpumask_var_t, select_rq_mask);
+static DEFINE_PER_CPU(cpumask_var_t, load_balance_mask);
+static DEFINE_PER_CPU(cpumask_var_t, select_rq_mask);
 
 #ifdef CONFIG_NO_HZ_COMMON
 
@@ -12074,6 +12074,13 @@ void show_numa_stats(struct task_struct *p, struct seq_file *m)
 __init void init_sched_fair_class(void)
 {
 #ifdef CONFIG_SMP
+	int i;
+
+	for_each_possible_cpu(i) {
+		zalloc_cpumask_var_node(&per_cpu(load_balance_mask, i), GFP_KERNEL, cpu_to_node(i));
+		zalloc_cpumask_var_node(&per_cpu(select_rq_mask,    i), GFP_KERNEL, cpu_to_node(i));
+	}
+
 	open_softirq(SCHED_SOFTIRQ, run_rebalance_domains);
 
 #ifdef CONFIG_NO_HZ_COMMON