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Subject[PATCH tip/core/rcu 10/11] rcu/nocb: Rename rcu_nocb_leader_stride kernel boot parameter
Date
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 <paulmck@linux.ibm.com>
---
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;
}

/*
--
2.17.1
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