diff mbox series

[v3,2/2] sched/fair: Use helper function to access rd->overutilized

Message ID 20240229104010.747411-3-sshegde@linux.ibm.com
State New
Headers
Series sched/fair: Limit access to overutilized |

Commit Message

Shrikanth Hegde Feb. 29, 2024, 10:40 a.m. UTC 
  Overutilized field is accessed directly in multiple places.
So it could use a helper function. That way one might be more
informed that it needs to be used only in case of EAS.

No change in functionality intended.

Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
---
 kernel/sched/fair.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

--
2.39.3
diff mbox series

Patch

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1f7d62b7c26f..99b5ddf92924 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6670,6 +6670,15 @@  static inline bool cpu_overutilized(int cpu)
 	return !util_fits_cpu(cpu_util_cfs(cpu), rq_util_min, rq_util_max, cpu);
 }

+/*
+ * Ensure that caller can do EAS. overutilized value
+ * make sense only if EAS is enabled
+ */
+static inline int is_rd_overutilized(struct root_domain *rd)
+{
+	return READ_ONCE(rd->overutilized);
+}
+
 static inline void set_rd_overutilized_status(struct root_domain *rd,
 					      unsigned int status)
 {
@@ -6686,13 +6695,14 @@  static inline void check_update_overutilized_status(struct rq *rq)
 	if (!sched_energy_enabled())
 		return;

-	if (!READ_ONCE(rq->rd->overutilized) && cpu_overutilized(rq->cpu))
+	if (!is_rd_overutilized(rq->rd) && cpu_overutilized(rq->cpu))
 		set_rd_overutilized_status(rq->rd, SG_OVERUTILIZED);
 }
 #else
 static inline void check_update_overutilized_status(struct rq *rq) { }
 static inline void set_rd_overutilized_status(struct root_domain *rd,
 					      unsigned int status) { }
+static inline int is_rd_overutilized(struct root_domain *rd) { }
 #endif

 /* Runqueue only has SCHED_IDLE tasks enqueued */
@@ -7974,7 +7984,7 @@  static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu)

 	rcu_read_lock();
 	pd = rcu_dereference(rd->pd);
-	if (!pd || READ_ONCE(rd->overutilized))
+	if (!pd || is_rd_overutilized(rd))
 		goto unlock;

 	/*
@@ -10859,7 +10869,7 @@  static struct sched_group *find_busiest_group(struct lb_env *env)
 	if (sched_energy_enabled()) {
 		struct root_domain *rd = env->dst_rq->rd;

-		if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized))
+		if (rcu_dereference(rd->pd) && !is_rd_overutilized(rd))
 			goto out_balanced;
 	}