sched: add comments for ifdefs in sched.c
make sched.c easier to read.
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/sched.c b/kernel/sched.c
index 84a3606..ef4e256 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -292,15 +292,15 @@
static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
/* Default task group's cfs_rq on each cpu */
static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
-#endif
-#else
+#endif /* CONFIG_RT_GROUP_SCHED */
+#else /* !CONFIG_FAIR_GROUP_SCHED */
#define root_task_group init_task_group
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
/* task_group_lock serializes add/remove of task groups and also changes to
* a task group's cpu shares.
@@ -310,9 +310,9 @@
#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_USER_SCHED
# define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD)
-#else
+#else /* !CONFIG_USER_SCHED */
# define INIT_TASK_GROUP_LOAD NICE_0_LOAD
-#endif
+#endif /* CONFIG_USER_SCHED */
/*
* A weight of 0, 1 or ULONG_MAX can cause arithmetics problems.
@@ -1316,15 +1316,15 @@
if (!tsk_is_polling(rq->idle))
smp_send_reschedule(cpu);
}
-#endif
+#endif /* CONFIG_NO_HZ */
-#else
+#else /* !CONFIG_SMP */
static void __resched_task(struct task_struct *p, int tif_bit)
{
assert_spin_locked(&task_rq(p)->lock);
set_tsk_thread_flag(p, tif_bit);
}
-#endif
+#endif /* CONFIG_SMP */
#if BITS_PER_LONG == 32
# define WMULT_CONST (~0UL)
@@ -2129,7 +2129,7 @@
}
}
}
-#endif
+#endif /* CONFIG_SCHEDSTATS */
out_activate:
#endif /* CONFIG_SMP */
@@ -2329,7 +2329,7 @@
notifier->ops->sched_out(notifier, next);
}
-#else
+#else /* !CONFIG_PREEMPT_NOTIFIERS */
static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
{
@@ -2341,7 +2341,7 @@
{
}
-#endif
+#endif /* CONFIG_PREEMPT_NOTIFIERS */
/**
* prepare_task_switch - prepare to switch tasks
@@ -6300,9 +6300,9 @@
}
kfree(groupmask);
}
-#else
+#else /* !CONFIG_SCHED_DEBUG */
# define sched_domain_debug(sd, cpu) do { } while (0)
-#endif
+#endif /* CONFIG_SCHED_DEBUG */
static int sd_degenerate(struct sched_domain *sd)
{
@@ -6598,7 +6598,7 @@
cpus_or(*span, *span, *nodemask);
}
}
-#endif
+#endif /* CONFIG_NUMA */
int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
@@ -6617,7 +6617,7 @@
*sg = &per_cpu(sched_group_cpus, cpu);
return cpu;
}
-#endif
+#endif /* CONFIG_SCHED_SMT */
/*
* multi-core sched-domains:
@@ -6625,7 +6625,7 @@
#ifdef CONFIG_SCHED_MC
static DEFINE_PER_CPU(struct sched_domain, core_domains);
static DEFINE_PER_CPU(struct sched_group, sched_group_core);
-#endif
+#endif /* CONFIG_SCHED_MC */
#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
static int
@@ -6727,7 +6727,7 @@
sg = sg->next;
} while (sg != group_head);
}
-#endif
+#endif /* CONFIG_NUMA */
#ifdef CONFIG_NUMA
/* Free memory allocated for various sched_group structures */
@@ -6764,11 +6764,11 @@
sched_group_nodes_bycpu[cpu] = NULL;
}
}
-#else
+#else /* !CONFIG_NUMA */
static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask)
{
}
-#endif
+#endif /* CONFIG_NUMA */
/*
* Initialize sched groups cpu_power.
@@ -7459,7 +7459,7 @@
#endif
return err;
}
-#endif
+#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
/*
* Force a reinitialization of the sched domains hierarchy. The domains
@@ -7677,8 +7677,8 @@
root_task_group.cfs_rq = (struct cfs_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
init_task_group.rt_se = (struct sched_rt_entity **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
@@ -7692,8 +7692,8 @@
root_task_group.rt_rq = (struct rt_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_RT_GROUP_SCHED */
}
#ifdef CONFIG_SMP
@@ -7709,8 +7709,8 @@
#ifdef CONFIG_USER_SCHED
init_rt_bandwidth(&root_task_group.rt_bandwidth,
global_rt_period(), RUNTIME_INF);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_GROUP_SCHED
list_add(&init_task_group.list, &task_groups);
@@ -7720,8 +7720,8 @@
INIT_LIST_HEAD(&root_task_group.children);
init_task_group.parent = &root_task_group;
list_add(&init_task_group.siblings, &root_task_group.children);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_GROUP_SCHED */
for_each_possible_cpu(i) {
struct rq *rq;
@@ -8040,7 +8040,7 @@
{
list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list);
}
-#else
+#else /* !CONFG_FAIR_GROUP_SCHED */
static inline void free_fair_sched_group(struct task_group *tg)
{
}
@@ -8058,7 +8058,7 @@
static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
{
}
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
static void free_rt_sched_group(struct task_group *tg)
@@ -8129,7 +8129,7 @@
{
list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list);
}
-#else
+#else /* !CONFIG_RT_GROUP_SCHED */
static inline void free_rt_sched_group(struct task_group *tg)
{
}
@@ -8147,7 +8147,7 @@
static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
{
}
-#endif
+#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_GROUP_SCHED
static void free_sched_group(struct task_group *tg)
@@ -8258,7 +8258,7 @@
task_rq_unlock(rq, &flags);
}
-#endif
+#endif /* CONFIG_GROUP_SCHED */
#ifdef CONFIG_FAIR_GROUP_SCHED
static void set_se_shares(struct sched_entity *se, unsigned long shares)
@@ -8508,7 +8508,7 @@
return ret;
}
-#else
+#else /* !CONFIG_RT_GROUP_SCHED */
static int sched_rt_global_constraints(void)
{
unsigned long flags;
@@ -8526,7 +8526,7 @@
return 0;
}
-#endif
+#endif /* CONFIG_RT_GROUP_SCHED */
int sched_rt_handler(struct ctl_table *table, int write,
struct file *filp, void __user *buffer, size_t *lenp,
@@ -8634,7 +8634,7 @@
return (u64) tg->shares;
}
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
@@ -8658,7 +8658,7 @@
{
return sched_group_rt_period(cgroup_tg(cgrp));
}
-#endif
+#endif /* CONFIG_RT_GROUP_SCHED */
static struct cftype cpu_files[] = {
#ifdef CONFIG_FAIR_GROUP_SCHED