From: Boqun Feng <boqun.feng@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: "Paul E . McKenney " <paulmck@linux.vnet.ibm.com>,
Josh Triplett <josh@joshtriplett.org>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Colin King <colin.king@canonical.com>,
Mark Rutland <mark.rutland@arm.com>,
Boqun Feng <boqun.feng@gmail.com>
Subject: [RFC v2 2/5] rcu: Use for_each_leaf_node_cpu() in RCU stall checking
Date: Thu, 15 Dec 2016 10:42:01 +0800 [thread overview]
Message-ID: <20161215024204.28620-3-boqun.feng@gmail.com> (raw)
In-Reply-To: <20161215024204.28620-1-boqun.feng@gmail.com>
Use for_each_leaf_node_cpu() in RCU stall checking code, to save some
extra checks, based on the fact that ->qsmask is mostly more sparse than
cpu_possible_mask.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
kernel/rcu/tree.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index b56e2dc31ba5..4e5b81c843de 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1417,10 +1417,11 @@ static void rcu_dump_cpu_stacks(struct rcu_state *rsp)
rcu_for_each_leaf_node(rsp, rnp) {
raw_spin_lock_irqsave_rcu_node(rnp, flags);
- for_each_leaf_node_possible_cpu(rnp, cpu)
- if (rnp->qsmask & leaf_node_cpu_bit(rnp, cpu))
- if (!trigger_single_cpu_backtrace(cpu))
- dump_cpu_task(cpu);
+
+ for_each_leaf_node_cpu(rnp, rnp->qsmask, cpu)
+ if (!trigger_single_cpu_backtrace(cpu))
+ dump_cpu_task(cpu);
+
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
}
@@ -1490,13 +1491,12 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
rcu_for_each_leaf_node(rsp, rnp) {
raw_spin_lock_irqsave_rcu_node(rnp, flags);
ndetected += rcu_print_task_stall(rnp);
- if (rnp->qsmask != 0) {
- for_each_leaf_node_possible_cpu(rnp, cpu)
- if (rnp->qsmask & leaf_node_cpu_bit(rnp, cpu)) {
- print_cpu_stall_info(rsp, cpu);
- ndetected++;
- }
+
+ for_each_leaf_node_cpu(rnp, rnp->qsmask, cpu) {
+ print_cpu_stall_info(rsp, cpu);
+ ndetected++;
}
+
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
--
2.10.2
next prev parent reply other threads:[~2016-12-15 2:43 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-15 2:41 [RFC v2 0/5] rcu: Introduce for_each_leaf_node_cpu() Boqun Feng
2016-12-15 2:42 ` [RFC v2 1/5] " Boqun Feng
2016-12-15 11:43 ` Mark Rutland
2016-12-15 14:38 ` Boqun Feng
2016-12-15 15:10 ` Mark Rutland
2016-12-15 15:14 ` Boqun Feng
2016-12-15 15:21 ` [RFC v2.1 " Boqun Feng
2016-12-15 15:29 ` Mark Rutland
2016-12-15 2:42 ` Boqun Feng [this message]
2016-12-15 2:42 ` [RFC v2 3/5] rcu: Use for_each_leaf_node_cpu() in ->expmask iteration Boqun Feng
2016-12-15 2:42 ` [RFC v2 4/5] rcu: Use for_each_leaf_node_cpu() in force_qs_rnp() Boqun Feng
2016-12-15 12:04 ` Mark Rutland
2016-12-15 14:42 ` Boqun Feng
2016-12-15 14:51 ` Colin Ian King
2016-12-19 15:15 ` Boqun Feng
2016-12-20 5:09 ` Paul E. McKenney
2016-12-20 5:59 ` Boqun Feng
2016-12-20 8:11 ` Boqun Feng
2016-12-20 15:32 ` Paul E. McKenney
2016-12-20 15:23 ` Paul E. McKenney
2016-12-21 2:34 ` Boqun Feng
2016-12-21 3:40 ` Paul E. McKenney
2016-12-21 4:18 ` Boqun Feng
2016-12-21 16:48 ` Paul E. McKenney
2016-12-22 1:08 ` Boqun Feng
2016-12-15 2:42 ` [RFC v2 5/5] rcu: Use for_each_leaf_node_cpu() in online CPU iteration Boqun Feng
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