The following commit has been merged into the sched/core branch of tip:
Commit-ID: c829d6818b60c591f70c060b2bb75d76cf0cec6d
Gitweb: https://git.kernel.org/tip/c829d6818b60c591f70c060b2bb75d76cf0cec6d
Author: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
AuthorDate: Mon, 25 Mar 2024 21:09:26 +05:30
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 26 Mar 2024 20:16:20 +01:00
sched/fair: Simplify the continue_balancing logic in sched_balance_newidle()
newidle(CPU_NEWLY_IDLE) balancing doesn't stop the load-balancing if the
continue_balancing flag is reset, but the other two balancing (IDLE, BUSY)
cases do that.
newidle balance stops the load balancing if rq has a task or there
is wakeup pending. The same checks are present in should_we_balance for
newidle. Hence use the return value and simplify continue_balancing
mechanism for newidle. Update the comment surrounding it as well.
No change in functionality intended.
Signed-off-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Link: https://lore.kernel.org/r/20240325153926.274284-1-sshegde@xxxxxxxxxxxxx
---
kernel/sched/fair.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 24a7530..1856e58 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -12358,6 +12358,7 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
{
unsigned long next_balance = jiffies + HZ;
int this_cpu = this_rq->cpu;
+ int continue_balancing = 1;
u64 t0, t1, curr_cost = 0;
struct sched_domain *sd;
int pulled_task = 0;
@@ -12372,8 +12373,9 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
return 0;
/*
- * We must set idle_stamp _before_ calling idle_balance(), such that we
- * measure the duration of idle_balance() as idle time.
+ * We must set idle_stamp _before_ calling sched_balance_rq()
+ * for CPU_NEWLY_IDLE, such that we measure the this duration
+ * as idle time.
*/
this_rq->idle_stamp = rq_clock(this_rq);
@@ -12412,7 +12414,6 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
rcu_read_lock();
for_each_domain(this_cpu, sd) {
- int continue_balancing = 1;
u64 domain_cost;
update_next_balance(sd, &next_balance);
@@ -12438,8 +12439,7 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
* Stop searching for tasks to pull if there are
* now runnable tasks on this rq.
*/
- if (pulled_task || this_rq->nr_running > 0 ||
- this_rq->ttwu_pending)
+ if (pulled_task || !continue_balancing)
break;
}
rcu_read_unlock();
|