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-rw-r--r--kernel/sched/fair.c31
-rw-r--r--kernel/sched/sched.h3
2 files changed, 28 insertions, 6 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 043715612227..3cfb4be3d88f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4144,6 +4144,8 @@ static inline void hrtick_update(struct rq *rq)
}
#endif
+static bool cpu_overutilized(int cpu);
+
/*
* The enqueue_task method is called before nr_running is
* increased. Here we update the fair scheduling stats and
@@ -4154,6 +4156,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
{
struct cfs_rq *cfs_rq;
struct sched_entity *se = &p->se;
+ int task_new = !(flags & ENQUEUE_WAKEUP);
for_each_sched_entity(se) {
if (se->on_rq)
@@ -4185,9 +4188,12 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
update_cfs_shares(cfs_rq);
}
- if (!se)
+ if (!se) {
add_nr_running(rq, 1);
-
+ if (!task_new && !rq->rd->overutilized &&
+ cpu_overutilized(rq->cpu))
+ rq->rd->overutilized = true;
+ }
hrtick_update(rq);
}
@@ -6651,11 +6657,12 @@ group_type group_classify(struct sched_group *group,
* @local_group: Does group contain this_cpu.
* @sgs: variable to hold the statistics for this group.
* @overload: Indicate more than one runnable task for any CPU.
+ * @overutilized: Indicate overutilization for any CPU.
*/
static inline void update_sg_lb_stats(struct lb_env *env,
struct sched_group *group, int load_idx,
int local_group, struct sg_lb_stats *sgs,
- bool *overload)
+ bool *overload, bool *overutilized)
{
unsigned long load;
int i;
@@ -6685,6 +6692,9 @@ static inline void update_sg_lb_stats(struct lb_env *env,
sgs->sum_weighted_load += weighted_cpuload(i);
if (idle_cpu(i))
sgs->idle_cpus++;
+
+ if (cpu_overutilized(i))
+ *overutilized = true;
}
/* Adjust by relative CPU capacity of the group */
@@ -6790,7 +6800,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
struct sched_group *sg = env->sd->groups;
struct sg_lb_stats tmp_sgs;
int load_idx, prefer_sibling = 0;
- bool overload = false;
+ bool overload = false, overutilized = false;
if (child && child->flags & SD_PREFER_SIBLING)
prefer_sibling = 1;
@@ -6812,7 +6822,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
}
update_sg_lb_stats(env, sg, load_idx, local_group, sgs,
- &overload);
+ &overload, &overutilized);
if (local_group)
goto next_group;
@@ -6856,8 +6866,14 @@ next_group:
/* update overload indicator if we are at root domain */
if (env->dst_rq->rd->overload != overload)
env->dst_rq->rd->overload = overload;
- }
+ /* Update over-utilization (tipping point, U >= 0) indicator */
+ if (env->dst_rq->rd->overutilized != overutilized)
+ env->dst_rq->rd->overutilized = overutilized;
+ } else {
+ if (!env->dst_rq->rd->overutilized && overutilized)
+ env->dst_rq->rd->overutilized = true;
+ }
}
/**
@@ -8250,6 +8266,9 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
if (static_branch_unlikely(&sched_numa_balancing))
task_tick_numa(rq, curr);
+
+ if (!rq->rd->overutilized && cpu_overutilized(task_cpu(curr)))
+ rq->rd->overutilized = true;
}
/*
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index a618db2936d4..5323d4fc1109 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -528,6 +528,9 @@ struct root_domain {
/* Indicate more than one runnable task for any CPU */
bool overload;
+ /* Indicate one or more cpus over-utilized (tipping point) */
+ bool overutilized;
+
/*
* The bit corresponding to a CPU gets set here if such CPU has more
* than one runnable -deadline task (as it is below for RT tasks).