From f7c612b000d7e974826089b5a6f6eecd6805862a Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 2 Apr 2019 08:05:55 -0700 Subject: [PATCH] rcu/nocb: Rename rcu_nocb_leader_stride kernel boot parameter This commit changes the name of the rcu_nocb_leader_stride kernel boot parameter to rcu_nocb_gp_stride in order to account for the new distinction between callback and grace-period no-CBs kthreads. Signed-off-by: Paul E. McKenney --- Documentation/admin-guide/kernel-parameters.txt | 13 +++++++------ kernel/rcu/tree_plugin.h | 8 ++++---- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index f3fcd6140ee1..79b983bedcaa 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3837,12 +3837,13 @@ RCU_BOOST is not set, valid values are 0-99 and the default is zero (non-realtime operation). - rcutree.rcu_nocb_leader_stride= [KNL] - Set the number of NOCB kthread groups, which - defaults to the square root of the number of - CPUs. Larger numbers reduces the wakeup overhead - on the per-CPU grace-period kthreads, but increases - that same overhead on each group's leader. + rcutree.rcu_nocb_gp_stride= [KNL] + Set the number of NOCB callback kthreads in + each group, which defaults to the square root + of the number of CPUs. Larger numbers reduce + the wakeup overhead on the global grace-period + kthread, but increases that same overhead on + each group's NOCB grace-period kthread. rcutree.qhimark= [KNL] Set threshold of queued RCU callbacks beyond which diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index be065aacd63b..80b27a9f306d 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2126,8 +2126,8 @@ static void __init rcu_spawn_nocb_kthreads(void) } /* How many CB CPU IDs per GP kthread? Default of -1 for sqrt(nr_cpu_ids). */ -static int rcu_nocb_leader_stride = -1; -module_param(rcu_nocb_leader_stride, int, 0444); +static int rcu_nocb_gp_stride = -1; +module_param(rcu_nocb_gp_stride, int, 0444); /* * Initialize GP-CB relationships for all no-CBs CPU. @@ -2135,7 +2135,7 @@ module_param(rcu_nocb_leader_stride, int, 0444); static void __init rcu_organize_nocb_kthreads(void) { int cpu; - int ls = rcu_nocb_leader_stride; + int ls = rcu_nocb_gp_stride; int nl = 0; /* Next GP kthread. */ struct rcu_data *rdp; struct rcu_data *rdp_gp = NULL; /* Suppress misguided gcc warn. */ @@ -2145,7 +2145,7 @@ static void __init rcu_organize_nocb_kthreads(void) return; if (ls == -1) { ls = int_sqrt(nr_cpu_ids); - rcu_nocb_leader_stride = ls; + rcu_nocb_gp_stride = ls; } /*