[tip: sched/core] sched/fair: Change likelyhood of nohz.nr_cpus

tip-bot2 for Shrikanth Hegde posted 1 patch 3 weeks, 2 days ago
kernel/sched/fair.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
[tip: sched/core] sched/fair: Change likelyhood of nohz.nr_cpus
Posted by tip-bot2 for Shrikanth Hegde 3 weeks, 2 days ago
The following commit has been merged into the sched/core branch of tip:

Commit-ID:     94e70734b4d034b9df795bd1ad3452ea96e742ca
Gitweb:        https://git.kernel.org/tip/94e70734b4d034b9df795bd1ad3452ea96e742ca
Author:        Shrikanth Hegde <sshegde@linux.ibm.com>
AuthorDate:    Thu, 15 Jan 2026 13:05:23 +05:30
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 15 Jan 2026 22:41:27 +01:00

sched/fair: Change likelyhood of nohz.nr_cpus

These days most of the system have multi cores. The likelyhood of
at least one or more CPUs in nohz (idle state) is higher.

Give accurate hint to the branch predictor.

Reviewed-and-tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://patch.msgid.link/20260115073524.376643-3-sshegde@linux.ibm.com
---
 kernel/sched/fair.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9afe0c6..4ae06ce 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -12459,9 +12459,9 @@ static void nohz_balancer_kick(struct rq *rq)
 
 	/*
 	 * None are in tickless mode and hence no need for NOHZ idle load
-	 * balancing:
+	 * balancing
 	 */
-	if (likely(!atomic_read(&nohz.nr_cpus)))
+	if (unlikely(!atomic_read(&nohz.nr_cpus)))
 		return;
 
 	if (rq->nr_running >= 2) {