[PATCH] sched: fix a compilation warning in sched_init()

[PATCH] sched: fix a compilation warning in sched_init()

[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
[-Wunused-but-set-variable]
  unsigned long alloc_size = 0, ptr;
                                ^~~
Use this opportunity to tidy up a code a bit by removing unnecssary
indentations and lines.

Signed-off-by: Qian Cai <cai@lca.pw>
---
 kernel/sched/core.c | 31 ++++++++++++-------------------
 1 file changed, 12 insertions(+), 19 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 874c427742a9..e7aff6d173a3 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5903,36 +5903,29 @@ int in_sched_functions(unsigned long addr)
 void __init sched_init(void)
 {
 	int i, j;
-	unsigned long alloc_size = 0, ptr;
+#if 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);
 
-	wait_bit_init();
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
-	alloc_size += 2 * nr_cpu_ids * sizeof(void **);
 #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 */
 #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 */
-	}
 #ifdef CONFIG_CPUMASK_OFFSTACK
 	for_each_possible_cpu(i) {
 		per_cpu(load_balance_mask, i) = (cpumask_var_t)kzalloc_node(
-- 
1.8.3.1

[tip:sched/core] sched/core: Clean up sched_init() a bit

[tip-bot for Qian Cai]

Commit-ID:  8d2bd61bd89260d5da5eaef7cf264587f19a7e0d
Gitweb:     https://git.kernel.org/tip/8d2bd61bd89260d5da5eaef7cf264587f19a7e0d
Author:     Qian Cai <cai@lca.pw>
AuthorDate: Wed, 22 May 2019 14:20:06 -0400
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 24 May 2019 08:57:29 +0200

sched/core: Clean up sched_init() a bit

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 and lines.

Signed-off-by: Qian Cai <cai@lca.pw>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1558549206-13031-1-git-send-email-cai@lca.pw
[ Also remove some of the unnecessary #endif comments. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/core.c | 45 +++++++++++++++++++--------------------------
 1 file changed, 19 insertions(+), 26 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 874c427742a9..9dc65b2957d1 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5903,36 +5903,29 @@ DECLARE_PER_CPU(cpumask_var_t, select_idle_mask);
 void __init sched_init(void)
 {
 	int i, j;
-	unsigned long alloc_size = 0, ptr;
+#if 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);
 
-	wait_bit_init();
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
-	alloc_size += 2 * nr_cpu_ids * sizeof(void **);
-#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 +5933,7 @@ 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 +5943,8 @@ 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 +5953,7 @@ 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 +6023,7 @@ 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);