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

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9afe0c69a3c110bce60142b3f1605720c41b431e..4ae06ce4a9168ecbaaafc9b47c0203cc51a49914 100644 (file)
--- 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) {