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Groups > linux.kernel > #1542452

[RFC v2 5/5] rcu: Use for_each_leaf_node_cpu() in online CPU iteration

From Boqun Feng <boqun.feng@gmail.com>
Newsgroups linux.kernel
Subject [RFC v2 5/5] rcu: Use for_each_leaf_node_cpu() in online CPU iteration
Date 2016-12-15 03:50 +0100
Message-ID <sOuhj-8sr-13@gated-at.bofh.it> (permalink)
References <sOuhj-8sr-5@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 for_each_leaf_node_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 | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 69c6eb27c37f..93cebd940a93 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1175,10 +1175,11 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
 		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)
+
+	for_each_leaf_node_cpu(rnp, mask, 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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Thread

[RFC v2 0/5] rcu: Introduce for_each_leaf_node_cpu() Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 03:50 +0100
  [RFC v2 1/5] rcu: Introduce for_each_leaf_node_cpu() Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 03:50 +0100
    Re: [RFC v2 1/5] rcu: Introduce for_each_leaf_node_cpu() Mark Rutland <mark.rutland@arm.com> - 2016-12-15 12:50 +0100
      Re: [RFC v2 1/5] rcu: Introduce for_each_leaf_node_cpu() Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 15:40 +0100
        Re: [RFC v2 1/5] rcu: Introduce for_each_leaf_node_cpu() Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 16:20 +0100
        Re: [RFC v2 1/5] rcu: Introduce for_each_leaf_node_cpu() Mark Rutland <mark.rutland@arm.com> - 2016-12-15 16:20 +0100
    [RFC v2.1 1/5] rcu: Introduce for_each_leaf_node_cpu() Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 16:30 +0100
      Re: [RFC v2.1 1/5] rcu: Introduce for_each_leaf_node_cpu() Mark Rutland <mark.rutland@arm.com> - 2016-12-15 16:40 +0100
  [RFC v2 2/5] rcu: Use for_each_leaf_node_cpu() in RCU stall checking Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 03:50 +0100
  [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 03:50 +0100
    Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Mark Rutland <mark.rutland@arm.com> - 2016-12-15 13:10 +0100
      Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 15:50 +0100
        Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Colin Ian King <colin.king@canonical.com> - 2016-12-15 16:00 +0100
          Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Boqun Feng <boqun.feng@gmail.com> - 2016-12-19 16:20 +0100
            Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-12-20 06:10 +0100
              Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Boqun Feng <boqun.feng@gmail.com> - 2016-12-20 07:00 +0100
                Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Boqun Feng <boqun.feng@gmail.com> - 2016-12-20 09:20 +0100
                Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-12-20 16:40 +0100
                Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-12-20 16:30 +0100
                Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Boqun Feng <boqun.feng@gmail.com> - 2016-12-21 03:40 +0100
                Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-12-21 04:50 +0100
                Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Boqun Feng <boqun.feng@gmail.com> - 2016-12-21 05:20 +0100
                Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-12-21 17:50 +0100
                Re: [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Boqun Feng <boqun.feng@gmail.com> - 2016-12-22 02:10 +0100
  [RFC v2 5/5] rcu: Use for_each_leaf_node_cpu() in online CPU iteration Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 03:50 +0100
  [RFC v2 3/5] rcu: Use for_each_leaf_node_cpu() in ->expmask iteration Boqun Feng <boqun.feng@gmail.com> - 2016-12-15 03:50 +0100

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