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Groups > linux.kernel > #1539204

[RFC 5/5] rcu: Use leaf_node_for_each_mask_*() for leaf node online CPU iteration

From Boqun Feng <boqun.feng@gmail.com>
Newsgroups linux.kernel
Subject [RFC 5/5] rcu: Use leaf_node_for_each_mask_*() for leaf node online CPU iteration
Date 2016-12-09 10:00 +0100
Message-ID <sMpc6-16k-23@gated-at.bofh.it> (permalink)
References <sMp2p-12O-13@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Though mostly identical, ->qsmaskinit(A.K.A rcu_rnp_online_cpus) is
sometimes more sparse than the corresponding part of cpu_possible_mask
for an RCU leaf node. So we use leaf_node_for_each_mask_possible_cpu()
in rcu_boost_kthread_setaffinity() instead to save some extra checks.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
 kernel/rcu/tree_plugin.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 69c6eb27c37f..c954c2a7a9ba 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1170,15 +1170,17 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
 	unsigned long mask = rcu_rnp_online_cpus(rnp);
 	cpumask_var_t cm;
 	int cpu;
+	unsigned long bit;
 
 	if (!t)
 		return;
 	if (!zalloc_cpumask_var(&cm, GFP_KERNEL))
 		return;
-	for_each_leaf_node_possible_cpu(rnp, cpu)
-		if ((mask & leaf_node_cpu_bit(rnp, cpu)) &&
-		    cpu != outgoingcpu)
+
+	leaf_node_for_each_mask_possible_cpu(rnp, mask, bit, cpu)
+		if (cpu != outgoingcpu)
 			cpumask_set_cpu(cpu, cm);
+
 	if (cpumask_weight(cm) == 0)
 		cpumask_setall(cm);
 	set_cpus_allowed_ptr(t, cm);
-- 
2.10.2

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[RFC 0/5] rcu: Introduce leaf_node_for_each_mask_possible_cpu() and its friend Boqun Feng <boqun.feng@gmail.com> - 2016-12-09 09:50 +0100
  [RFC 5/5] rcu: Use leaf_node_for_each_mask_*() for leaf node online CPU iteration Boqun Feng <boqun.feng@gmail.com> - 2016-12-09 10:00 +0100
  Re: [RFC 0/5] rcu: Introduce leaf_node_for_each_mask_possible_cpu()  and its friend "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-12-10 00:50 +0100
    Re: [RFC 0/5] rcu: Introduce leaf_node_for_each_mask_possible_cpu()  and its friend Boqun Feng <boqun.feng@gmail.com> - 2016-12-10 01:50 +0100
      Re: [RFC 0/5] rcu: Introduce leaf_node_for_each_mask_possible_cpu()  and its friend "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-12-10 05:30 +0100
        Re: [RFC 0/5] rcu: Introduce leaf_node_for_each_mask_possible_cpu()  and its friend Boqun Feng <boqun.feng@gmail.com> - 2016-12-10 14:40 +0100
          Re: [RFC 0/5] rcu: Introduce leaf_node_for_each_mask_possible_cpu()  and its friend "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-12-10 18:40 +0100
            Re: [RFC 0/5] rcu: Introduce leaf_node_for_each_mask_possible_cpu()  and its friend Boqun Feng <boqun.feng@gmail.com> - 2016-12-11 01:10 +0100

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