Currently, when the square root of the number of CPUs is rounded down
by int_sqrt(), this round-down is applied to the number of callback
kthreads per grace-period kthreads. This makes almost no difference
for large systems, but results in oddities such as three no-CBs
grace-period kthreads for a five-CPU system, which is a bit excessive.
This commit therefore causes the round-down to apply to the number of
no-CBs grace-period kthreads, so that systems with from four to eight
CPUs have only two no-CBs grace period kthreads.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
---
kernel/rcu/tree_plugin.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index b6d9ed169edc..06b4fe275b3a 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2026,7 +2026,7 @@ static void __init rcu_organize_nocb_kthreads(void)
if (!cpumask_available(rcu_nocb_mask))
return;
if (ls == -1) {
- ls = int_sqrt(nr_cpu_ids);
+ ls = nr_cpu_ids / int_sqrt(nr_cpu_ids);
rcu_nocb_gp_stride = ls;
}
--
2.17.1
