2022-03-03 14:48:23

by Henry Tseng

Subject: [PATCH v3] sched: Simplify __sched_init runtime checks

Improve runtime checks in __sched_init(void) by replacing if conditional
checks with preprocessor directives.

Signed-off-by: Chun-Hung Tseng <[email protected]>
---
kernel/sched/core.c | 29 +++++++++++++++--------------
1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9745613d531c..003e8677f6ba 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -9317,28 +9317,29 @@ void __init sched_init(void)
#ifdef CONFIG_RT_GROUP_SCHED
ptr += 2 * nr_cpu_ids * sizeof(void **);
#endif
- if (ptr) {
- ptr = (unsigned long)kzalloc(ptr, GFP_NOWAIT);
+
+#if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
+ ptr = (unsigned long)kzalloc(ptr, GFP_NOWAIT);

#ifdef CONFIG_FAIR_GROUP_SCHED
- root_task_group.se = (struct sched_entity **)ptr;
- ptr += nr_cpu_ids * sizeof(void **);
+ root_task_group.se = (struct sched_entity **)ptr;
+ ptr += nr_cpu_ids * sizeof(void **);

- root_task_group.cfs_rq = (struct cfs_rq **)ptr;
- ptr += nr_cpu_ids * sizeof(void **);
+ root_task_group.cfs_rq = (struct cfs_rq **)ptr;
+ ptr += nr_cpu_ids * sizeof(void **);

- root_task_group.shares = ROOT_TASK_GROUP_LOAD;
- init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
+ root_task_group.shares = ROOT_TASK_GROUP_LOAD;
+ init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
- root_task_group.rt_se = (struct sched_rt_entity **)ptr;
- ptr += nr_cpu_ids * sizeof(void **);
-
- root_task_group.rt_rq = (struct rt_rq **)ptr;
- ptr += nr_cpu_ids * sizeof(void **);
+ root_task_group.rt_se = (struct sched_rt_entity **)ptr;
+ ptr += nr_cpu_ids * sizeof(void **);

+ root_task_group.rt_rq = (struct rt_rq **)ptr;
+ ptr += nr_cpu_ids * sizeof(void **);
#endif /* CONFIG_RT_GROUP_SCHED */
- }
+#endif /* CONFIG_FAIR_GROUP_SCHED || CONFIG_RT_GROUP_SCHED */
+
#ifdef CONFIG_CPUMASK_OFFSTACK
for_each_possible_cpu(i) {
per_cpu(load_balance_mask, i) = (cpumask_var_t)kzalloc_node(
--
2.35.1

2022-05-22 09:08:28

by Henry Tseng

Subject: Re: [PATCH v3] sched: Simplify __sched_init runtime checks

A friendly ping on this patch!

On Thu, Mar 3, 2022 at 2:19 PM Chun-Hung Tseng <[email protected]> wrote:
>
> Improve runtime checks in __sched_init(void) by replacing if conditional
> checks with preprocessor directives.
>
> Signed-off-by: Chun-Hung Tseng <[email protected]>
> ---
> kernel/sched/core.c | 29 +++++++++++++++--------------
> 1 file changed, 15 insertions(+), 14 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 9745613d531c..003e8677f6ba 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -9317,28 +9317,29 @@ void __init sched_init(void)
> #ifdef CONFIG_RT_GROUP_SCHED
> ptr += 2 * nr_cpu_ids * sizeof(void **);
> #endif
> - if (ptr) {
> - ptr = (unsigned long)kzalloc(ptr, GFP_NOWAIT);
> +
> +#if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
> + ptr = (unsigned long)kzalloc(ptr, GFP_NOWAIT);
>
> #ifdef CONFIG_FAIR_GROUP_SCHED
> - root_task_group.se = (struct sched_entity **)ptr;
> - ptr += nr_cpu_ids * sizeof(void **);
> + root_task_group.se = (struct sched_entity **)ptr;
> + ptr += nr_cpu_ids * sizeof(void **);
>
> - root_task_group.cfs_rq = (struct cfs_rq **)ptr;
> - ptr += nr_cpu_ids * sizeof(void **);
> + root_task_group.cfs_rq = (struct cfs_rq **)ptr;
> + ptr += nr_cpu_ids * sizeof(void **);
>
> - root_task_group.shares = ROOT_TASK_GROUP_LOAD;
> - init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
> + root_task_group.shares = ROOT_TASK_GROUP_LOAD;
> + init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
> #endif /* CONFIG_FAIR_GROUP_SCHED */
> #ifdef CONFIG_RT_GROUP_SCHED
> - root_task_group.rt_se = (struct sched_rt_entity **)ptr;
> - ptr += nr_cpu_ids * sizeof(void **);
> -
> - root_task_group.rt_rq = (struct rt_rq **)ptr;
> - ptr += nr_cpu_ids * sizeof(void **);
> + root_task_group.rt_se = (struct sched_rt_entity **)ptr;
> + ptr += nr_cpu_ids * sizeof(void **);
>
> + root_task_group.rt_rq = (struct rt_rq **)ptr;
> + ptr += nr_cpu_ids * sizeof(void **);
> #endif /* CONFIG_RT_GROUP_SCHED */
> - }
> +#endif /* CONFIG_FAIR_GROUP_SCHED || CONFIG_RT_GROUP_SCHED */
> +
> #ifdef CONFIG_CPUMASK_OFFSTACK
> for_each_possible_cpu(i) {
> per_cpu(load_balance_mask, i) = (cpumask_var_t)kzalloc_node(
> --
> 2.35.1
>


--
Best wishes,
Henry