[tip: core/rcu] rcu: Switch force_qs_rnp() to for_each_leaf_node_cpu_mask()

From: tip-bot2 for Paul E. McKenney
Date: Sat Jan 25 2020 - 05:42:46 EST


The following commit has been merged into the core/rcu branch of tip:

Commit-ID: 7441e7661d6586ae36329b7956e4d713d81e9903
Gitweb: https://git.kernel.org/tip/7441e7661d6586ae36329b7956e4d713d81e9903
Author: Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate: Wed, 30 Oct 2019 09:37:11 -07:00
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Fri, 24 Jan 2020 10:33:51 -08:00

rcu: Switch force_qs_rnp() to for_each_leaf_node_cpu_mask()

Currently, force_qs_rnp() uses a for_each_leaf_node_possible_cpu()
loop containing a check of the current CPU's bit in ->qsmask.
This works, but this commit saves three lines by instead using
for_each_leaf_node_cpu_mask(), which combines the functionality of
for_each_leaf_node_possible_cpu() and leaf_node_cpu_bit(). This commit
also replaces the use of the local variable "bit" with rdp->grpmask.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/tree.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index bbb60ed..d950764 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2298,14 +2298,11 @@ static void force_qs_rnp(int (*f)(struct rcu_data *rdp))
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
continue;
}
- for_each_leaf_node_possible_cpu(rnp, cpu) {
- unsigned long bit = leaf_node_cpu_bit(rnp, cpu);
- if ((rnp->qsmask & bit) != 0) {
- rdp = per_cpu_ptr(&rcu_data, cpu);
- if (f(rdp)) {
- mask |= bit;
- rcu_disable_urgency_upon_qs(rdp);
- }
+ for_each_leaf_node_cpu_mask(rnp, cpu, rnp->qsmask) {
+ rdp = per_cpu_ptr(&rcu_data, cpu);
+ if (f(rdp)) {
+ mask |= rdp->grpmask;
+ rcu_disable_urgency_upon_qs(rdp);
}
}
if (mask != 0) {