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

From: tip-bot2 for Bing Huang
Date: Wed Aug 03 2022 - 13:31:00 EST


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@xxxxxxxxxx>
AuthorDate: Sat, 23 Jul 2022 05:36:09 +08:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Reviewed-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220722213609.3901-1-huangbing775@xxxxxxx
---
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