* [PATCH v2] sched/core: clean up sched_init() a bit
@ 2019-06-04 20:46 Qian Cai
2019-06-19 14:36 ` Qian Cai
0 siblings, 1 reply; 2+ messages in thread
From: Qian Cai @ 2019-06-04 20:46 UTC (permalink / raw)
To: akpm; +Cc: mingo, peterz, torvalds, tglx, linux-kernel, Qian Cai
Compiling a kernel with both FAIR_GROUP_SCHED=n and RT_GROUP_SCHED=n
will generate a warning using W=1:
kernel/sched/core.c: In function 'sched_init':
kernel/sched/core.c:5906:32: warning: variable 'ptr' set but not used
Use this opportunity to tidy up a code a bit by removing unnecssary
indentations, #endif comments and lines.
Signed-off-by: Qian Cai <cai@lca.pw>
---
v2: Fix an oversight when both FAIR_GROUP_SCHED and RT_GROUP_SCHED
selected which was found by the 0day kernel testing robot.
kernel/sched/core.c | 50 +++++++++++++++++++++++---------------------------
1 file changed, 23 insertions(+), 27 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 874c427742a9..edebd5e97542 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5903,36 +5903,31 @@ int in_sched_functions(unsigned long addr)
void __init sched_init(void)
{
int i, j;
- unsigned long alloc_size = 0, ptr;
-
- wait_bit_init();
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
- alloc_size += 2 * nr_cpu_ids * sizeof(void **);
+#if defined(CONFIG_FAIR_GROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED)
+ unsigned long alloc_size = 4 * nr_cpu_ids * sizeof(void **);
+ unsigned long ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
+#elif defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
+ unsigned long alloc_size = 2 * nr_cpu_ids * sizeof(void **);
+ unsigned long ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
#endif
-#ifdef CONFIG_RT_GROUP_SCHED
- alloc_size += 2 * nr_cpu_ids * sizeof(void **);
-#endif
- if (alloc_size) {
- ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
+ wait_bit_init();
#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 **);
-#endif /* CONFIG_FAIR_GROUP_SCHED */
+#endif
#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_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_rq = (struct rt_rq **)ptr;
+ ptr += nr_cpu_ids * sizeof(void **);
-#endif /* CONFIG_RT_GROUP_SCHED */
- }
+#endif
#ifdef CONFIG_CPUMASK_OFFSTACK
for_each_possible_cpu(i) {
per_cpu(load_balance_mask, i) = (cpumask_var_t)kzalloc_node(
@@ -5940,7 +5935,7 @@ void __init sched_init(void)
per_cpu(select_idle_mask, i) = (cpumask_var_t)kzalloc_node(
cpumask_size(), GFP_KERNEL, cpu_to_node(i));
}
-#endif /* CONFIG_CPUMASK_OFFSTACK */
+#endif
init_rt_bandwidth(&def_rt_bandwidth, global_rt_period(), global_rt_runtime());
init_dl_bandwidth(&def_dl_bandwidth, global_rt_period(), global_rt_runtime());
@@ -5950,9 +5945,9 @@ void __init sched_init(void)
#endif
#ifdef CONFIG_RT_GROUP_SCHED
- init_rt_bandwidth(&root_task_group.rt_bandwidth,
- global_rt_period(), global_rt_runtime());
-#endif /* CONFIG_RT_GROUP_SCHED */
+ init_rt_bandwidth(&root_task_group.rt_bandwidth, global_rt_period(),
+ global_rt_runtime());
+#endif
#ifdef CONFIG_CGROUP_SCHED
task_group_cache = KMEM_CACHE(task_group, 0);
@@ -5961,7 +5956,7 @@ void __init sched_init(void)
INIT_LIST_HEAD(&root_task_group.children);
INIT_LIST_HEAD(&root_task_group.siblings);
autogroup_init(&init_task);
-#endif /* CONFIG_CGROUP_SCHED */
+#endif
for_each_possible_cpu(i) {
struct rq *rq;
@@ -6031,6 +6026,7 @@ void __init sched_init(void)
rq->last_blocked_load_update_tick = jiffies;
atomic_set(&rq->nohz_flags, 0);
#endif
+
#endif /* CONFIG_SMP */
hrtick_rq_init(rq);
atomic_set(&rq->nr_iowait, 0);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] sched/core: clean up sched_init() a bit
2019-06-04 20:46 [PATCH v2] sched/core: clean up sched_init() a bit Qian Cai
@ 2019-06-19 14:36 ` Qian Cai
0 siblings, 0 replies; 2+ messages in thread
From: Qian Cai @ 2019-06-19 14:36 UTC (permalink / raw)
To: akpm; +Cc: mingo, peterz, torvalds, tglx, linux-kernel
Ping.
On Tue, 2019-06-04 at 16:46 -0400, Qian Cai wrote:
> Compiling a kernel with both FAIR_GROUP_SCHED=n and RT_GROUP_SCHED=n
> will generate a warning using W=1:
>
> kernel/sched/core.c: In function 'sched_init':
> kernel/sched/core.c:5906:32: warning: variable 'ptr' set but not used
>
> Use this opportunity to tidy up a code a bit by removing unnecssary
> indentations, #endif comments and lines.
>
> Signed-off-by: Qian Cai <cai@lca.pw>
> ---
>
> v2: Fix an oversight when both FAIR_GROUP_SCHED and RT_GROUP_SCHED
> selected which was found by the 0day kernel testing robot.
>
> kernel/sched/core.c | 50 +++++++++++++++++++++++---------------------------
> 1 file changed, 23 insertions(+), 27 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 874c427742a9..edebd5e97542 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -5903,36 +5903,31 @@ int in_sched_functions(unsigned long addr)
> void __init sched_init(void)
> {
> int i, j;
> - unsigned long alloc_size = 0, ptr;
> -
> - wait_bit_init();
> -
> -#ifdef CONFIG_FAIR_GROUP_SCHED
> - alloc_size += 2 * nr_cpu_ids * sizeof(void **);
> +#if defined(CONFIG_FAIR_GROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED)
> + unsigned long alloc_size = 4 * nr_cpu_ids * sizeof(void **);
> + unsigned long ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
> +#elif defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
> + unsigned long alloc_size = 2 * nr_cpu_ids * sizeof(void **);
> + unsigned long ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
> #endif
> -#ifdef CONFIG_RT_GROUP_SCHED
> - alloc_size += 2 * nr_cpu_ids * sizeof(void **);
> -#endif
> - if (alloc_size) {
> - ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
> + wait_bit_init();
>
> #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 **);
>
> -#endif /* CONFIG_FAIR_GROUP_SCHED */
> +#endif
> #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_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_rq = (struct rt_rq **)ptr;
> + ptr += nr_cpu_ids * sizeof(void **);
>
> -#endif /* CONFIG_RT_GROUP_SCHED */
> - }
> +#endif
> #ifdef CONFIG_CPUMASK_OFFSTACK
> for_each_possible_cpu(i) {
> per_cpu(load_balance_mask, i) = (cpumask_var_t)kzalloc_node(
> @@ -5940,7 +5935,7 @@ void __init sched_init(void)
> per_cpu(select_idle_mask, i) = (cpumask_var_t)kzalloc_node(
> cpumask_size(), GFP_KERNEL, cpu_to_node(i));
> }
> -#endif /* CONFIG_CPUMASK_OFFSTACK */
> +#endif
>
> init_rt_bandwidth(&def_rt_bandwidth, global_rt_period(),
> global_rt_runtime());
> init_dl_bandwidth(&def_dl_bandwidth, global_rt_period(),
> global_rt_runtime());
> @@ -5950,9 +5945,9 @@ void __init sched_init(void)
> #endif
>
> #ifdef CONFIG_RT_GROUP_SCHED
> - init_rt_bandwidth(&root_task_group.rt_bandwidth,
> - global_rt_period(), global_rt_runtime());
> -#endif /* CONFIG_RT_GROUP_SCHED */
> + init_rt_bandwidth(&root_task_group.rt_bandwidth, global_rt_period(),
> + global_rt_runtime());
> +#endif
>
> #ifdef CONFIG_CGROUP_SCHED
> task_group_cache = KMEM_CACHE(task_group, 0);
> @@ -5961,7 +5956,7 @@ void __init sched_init(void)
> INIT_LIST_HEAD(&root_task_group.children);
> INIT_LIST_HEAD(&root_task_group.siblings);
> autogroup_init(&init_task);
> -#endif /* CONFIG_CGROUP_SCHED */
> +#endif
>
> for_each_possible_cpu(i) {
> struct rq *rq;
> @@ -6031,6 +6026,7 @@ void __init sched_init(void)
> rq->last_blocked_load_update_tick = jiffies;
> atomic_set(&rq->nohz_flags, 0);
> #endif
> +
> #endif /* CONFIG_SMP */
> hrtick_rq_init(rq);
> atomic_set(&rq->nr_iowait, 0);
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