Commit f7c612b0 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

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: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
parent f7c9a9b6

Documentation/admin-guide/kernel-parameters.txt

+7 −6
Original line number Diff line number Diff line
@@ -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

kernel/rcu/tree_plugin.h

+4 −4
Original line number Diff line number Diff line
@@ -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;

	}



	/*