Some validation for task moving is performed in move_tasks() and
move_one_task(). We can move these code to can_migrate_task()
which is already exist for this purpose.
Signed-off-by: Joonsoo Kim <iamjoonsoo....@lge.com>
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 97498f4..849bc8e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3874,19 +3874,40 @@ task_hot(struct task_struct *p, u64 now, struct
sched_domain *sd)
return delta < (s64)sysctl_sched_migration_cost;
}
+static unsigned long task_h_load(struct task_struct *p);
+
/*
* can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
+ * @load is only meaningful when !@lb_active and return value is true
*/
static
-int can_migrate_task(struct task_struct *p, struct lb_env *env)
+int can_migrate_task(struct task_struct *p, struct lb_env *env,
+ bool lb_active, unsigned long *load)
{
int tsk_cache_hot = 0;
/*
* We do not migrate tasks that are:
- * 1) running (obviously), or
- * 2) cannot be migrated to this CPU due to cpus_allowed, or
- * 3) are cache-hot on their current CPU.
+ * 1) throttled_lb_pair, or
+ * 2) task's load is too low, or
+ * 3) task's too large to imbalance, or
+ * 4) cannot be migrated to this CPU due to cpus_allowed, or
+ * 5) running (obviously), or
+ * 6) are cache-hot on their current CPU.
*/
+
+ if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
+ return 0;
+
+ if (!lb_active) {
+ *load = task_h_load(p);
+ if (sched_feat(LB_MIN) &&
+ *load < 16 && !env->sd->nr_balance_failed)
+ return 0;
+
+ if ((*load / 2) > env->imbalance)
+ return 0;
+ }
+
if (!cpumask_test_cpu(env->dst_cpu, tsk_cpus_allowed(p))) {
int new_dst_cpu;
@@ -3957,10 +3978,7 @@ static int move_one_task(struct lb_env *env)
struct task_struct *p, *n;
list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) {
- if (throttled_lb_pair(task_group(p), env->src_rq->cpu,
env->dst_cpu))
- continue;
-
- if (!can_migrate_task(p, env))
+ if (!can_migrate_task(p, env, true, NULL))
continue;
move_task(p, env);
@@ -3975,8 +3993,6 @@ static int move_one_task(struct lb_env *env)
return 0;
}
-static unsigned long task_h_load(struct task_struct *p);
-
static const unsigned int sched_nr_migrate_break = 32;
/*
@@ -4011,18 +4027,7 @@ static int move_tasks(struct lb_env *env)
break;
}
- if (throttled_lb_pair(task_group(p), env->src_cpu,
env->dst_cpu))
- goto next;
-
- load = task_h_load(p);
-
- if (sched_feat(LB_MIN) && load < 16 &&
!env->sd->nr_balance_failed)
- goto next;
-
- if ((load / 2) > env->imbalance)
- goto next;
-
- if (!can_migrate_task(p, env))
+ if (!can_migrate_task(p, env, false, &load))
goto next;
move_task(p, env);
--
1.7.9.5
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