From: Qian Cai <cai@lca.pw>
To: akpm@linux-foundation.org
Cc: mingo@kernel.org, peterz@infradead.org,
torvalds@linux-foundation.org, tglx@linutronix.de,
linux-kernel@vger.kernel.org, Qian Cai <cai@lca.pw>
Subject: [PATCH v2] sched/core: clean up sched_init() a bit
Date: Tue, 4 Jun 2019 16:46:02 -0400 [thread overview]
Message-ID: <1559681162-5385-1-git-send-email-cai@lca.pw> (raw)
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
next reply other threads:[~2019-06-04 20:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-04 20:46 Qian Cai [this message]
2019-06-19 14:36 ` [PATCH v2] sched/core: clean up sched_init() a bit Qian Cai
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