Commit 9fcb09bd authored Jun 01, 2019 by Paul E. McKenney

rcu/nocb: Round down for number of no-CBs grace-period kthreads

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@linux.ibm.com>

parent 81c0b3d7

kernel/rcu/tree_plugin.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -2028,7 +2028,7 @@ 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;
		}

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