Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH tip/core/rcu 06/10] rcu/nocb: Round down for number of no-CBs grace-period kthreads | Date | Thu, 1 Aug 2019 16:16:31 -0700 |
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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> --- 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
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