[PATCH v2 2/2] sched/fair: Use helper functions to access rd->overload

From: Shrikanth Hegde
Date: Fri Mar 22 2024 - 10:17:56 EST


rd->overload is accessed at multiple places. Instead it could use helper
get/set functions. This would make the code more readable and easy to
maintain.

No change in functionality intended.

Suggested-by: Qais Yousef <qyousef@xxxxxxxxxxx>
Signed-off-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
Reviewed-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
kernel/sched/fair.c | 7 ++++---
kernel/sched/sched.h | 14 ++++++++++++--
2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index eeebadd7d9ae..cee99c93e6a4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10621,8 +10621,9 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd

if (!env->sd->parent) {
/* update overload indicator if we are at root domain */
- if (READ_ONCE(env->dst_rq->rd->overload) != (sg_status & SG_OVERLOAD))
- WRITE_ONCE(env->dst_rq->rd->overload, sg_status & SG_OVERLOAD);
+ if (is_rd_overloaded(env->dst_rq->rd) != (sg_status & SG_OVERLOAD))
+ set_rd_overload_status(env->dst_rq->rd,
+ sg_status & SG_OVERLOAD);

/* Update over-utilization (tipping point, U >= 0) indicator */
set_rd_overutilized_status(env->dst_rq->rd,
@@ -12344,7 +12345,7 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
rcu_read_lock();
sd = rcu_dereference_check_sched_domain(this_rq->sd);

- if (!READ_ONCE(this_rq->rd->overload) ||
+ if (!is_rd_overloaded(this_rq->rd) ||
(sd && this_rq->avg_idle < sd->max_newidle_lb_cost)) {

if (sd)
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 41024c1c49b4..c91eb8811bef 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -918,6 +918,16 @@ extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
extern void sched_get_rd(struct root_domain *rd);
extern void sched_put_rd(struct root_domain *rd);

+static inline int is_rd_overloaded(struct root_domain *rd)
+{
+ return READ_ONCE(rd->overload);
+}
+
+static inline void set_rd_overload_status(struct root_domain *rd, int status)
+{
+ WRITE_ONCE(rd->overload, status);
+}
+
#ifdef HAVE_RT_PUSH_IPI
extern void rto_push_irq_work_func(struct irq_work *work);
#endif
@@ -2518,8 +2528,8 @@ static inline void add_nr_running(struct rq *rq, unsigned count)

#ifdef CONFIG_SMP
if (prev_nr < 2 && rq->nr_running >= 2) {
- if (!READ_ONCE(rq->rd->overload))
- WRITE_ONCE(rq->rd->overload, 1);
+ if (!is_rd_overloaded(rq->rd))
+ set_rd_overload_status(rq->rd, 1);
}
#endif

--
2.39.3