From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
jiangshanlai@gmail.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
"Paul E. McKenney" <paulmck@linux.ibm.com>
Subject: [PATCH tip/core/rcu 10/11] rcu/nocb: Rename rcu_nocb_leader_stride kernel boot parameter
Date: Thu, 1 Aug 2019 15:50:27 -0700 [thread overview]
Message-ID: <20190801225028.18225-10-paulmck@linux.ibm.com> (raw)
In-Reply-To: <20190801225009.GA17155@linux.ibm.com>
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
next prev parent reply other threads:[~2019-08-01 22:50 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-01 22:50 [PATCH tip/core/rcu 0/11] No-CBs grace-period kthread updates for v5.3-rc2 Paul E. McKenney
2019-08-01 22:50 ` [PATCH tip/core/rcu 01/11] rcu/nocb: Rename rcu_data fields to prepare for forward-progress work Paul E. McKenney
2019-08-01 22:50 ` [PATCH tip/core/rcu 02/11] rcu/nocb: Update comments " Paul E. McKenney
2019-08-01 22:50 ` [PATCH tip/core/rcu 03/11] rcu/nocb: Provide separate no-CBs grace-period kthreads Paul E. McKenney
2019-08-03 17:41 ` Joel Fernandes
2019-08-03 19:46 ` Paul E. McKenney
2019-08-04 19:24 ` Joel Fernandes
2019-08-01 22:50 ` [PATCH tip/core/rcu 04/11] rcu/nocb: Rename nocb_follower_wait() to nocb_cb_wait() Paul E. McKenney
2019-08-01 22:50 ` [PATCH tip/core/rcu 05/11] rcu/nocb: Rename wake_nocb_leader() to wake_nocb_gp() Paul E. McKenney
2019-08-01 22:50 ` [PATCH tip/core/rcu 06/11] rcu/nocb: Rename __wake_nocb_leader() to __wake_nocb_gp() Paul E. McKenney
2019-08-01 22:50 ` [PATCH tip/core/rcu 07/11] rcu/nocb: Rename wake_nocb_leader_defer() to wake_nocb_gp_defer() Paul E. McKenney
2019-08-01 22:50 ` [PATCH tip/core/rcu 08/11] rcu/nocb: Rename rcu_organize_nocb_kthreads() local variable Paul E. McKenney
2019-08-01 22:50 ` [PATCH tip/core/rcu 09/11] rcu/nocb: Rename and document no-CB CB kthread sleep trace event Paul E. McKenney
2019-08-01 22:50 ` Paul E. McKenney [this message]
2019-08-01 22:50 ` [PATCH tip/core/rcu 11/11] rcu/nocb: Print gp/cb kthread hierarchy if dump_tree Paul E. McKenney
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