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From: Lai Jiangshan <laijs@linux.alibaba.com>
To: linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@linux.alibaba.com>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Josh Triplett <josh@joshtriplett.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	rcu@vger.kernel.org
Subject: [PATCH 03/11] rcu: clean up rcu_preempt_deferred_qs_irqrestore()
Date: Thu, 31 Oct 2019 10:07:58 +0000	[thread overview]
Message-ID: <20191031100806.1326-4-laijs@linux.alibaba.com> (raw)
In-Reply-To: <20191031100806.1326-1-laijs@linux.alibaba.com>

Remove several unneeded return.

It doesn't need to return earlier after every code block.
The code protects itself and be safe to fall through because
every code block has its own condition tests.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
 kernel/rcu/tree_plugin.h | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 59ef10da1e39..82595db04eec 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -439,19 +439,10 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags)
 	 * t->rcu_read_unlock_special cannot change.
 	 */
 	special = t->rcu_read_unlock_special;
-	rdp = this_cpu_ptr(&rcu_data);
-	if (!special.s && !rdp->exp_deferred_qs) {
-		local_irq_restore(flags);
-		return;
-	}
 	t->rcu_read_unlock_special.b.deferred_qs = false;
 	if (special.b.need_qs) {
 		rcu_qs();
 		t->rcu_read_unlock_special.b.need_qs = false;
-		if (!t->rcu_read_unlock_special.s && !rdp->exp_deferred_qs) {
-			local_irq_restore(flags);
-			return;
-		}
 	}
 
 	/*
@@ -460,12 +451,9 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags)
 	 * tasks are handled when removing the task from the
 	 * blocked-tasks list below.
 	 */
+	rdp = this_cpu_ptr(&rcu_data);
 	if (rdp->exp_deferred_qs) {
 		rcu_report_exp_rdp(rdp);
-		if (!t->rcu_read_unlock_special.s) {
-			local_irq_restore(flags);
-			return;
-		}
 	}
 
 	/* Clean up if blocked during RCU read-side critical section. */
-- 
2.20.1


  parent reply	other threads:[~2019-10-31 10:08 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-31 10:07 [PATCH 00/11] rcu: introduce percpu rcu_preempt_depth Lai Jiangshan
2019-10-31 10:07 ` [PATCH 01/11] rcu: avoid leaking exp_deferred_qs into next GP Lai Jiangshan
2019-10-31 13:43   ` Paul E. McKenney
2019-10-31 18:19     ` Lai Jiangshan
2019-10-31 19:00       ` Paul E. McKenney
2019-10-31 10:07 ` [PATCH 02/11] rcu: fix bug when rcu_exp_handler() in nested interrupt Lai Jiangshan
2019-10-31 13:47   ` Paul E. McKenney
2019-10-31 14:20     ` Lai Jiangshan
2019-10-31 14:31     ` Paul E. McKenney
2019-10-31 15:14       ` Lai Jiangshan
2019-10-31 18:52         ` Paul E. McKenney
2019-11-01  0:19           ` Boqun Feng
2019-11-01  2:29             ` Lai Jiangshan
2019-10-31 10:07 ` Lai Jiangshan [this message]
2019-10-31 13:52   ` [PATCH 03/11] rcu: clean up rcu_preempt_deferred_qs_irqrestore() Paul E. McKenney
2019-10-31 15:25     ` Lai Jiangshan
2019-10-31 18:57       ` Paul E. McKenney
2019-10-31 19:02         ` Paul E. McKenney
2019-10-31 10:07 ` [PATCH 04/11] rcu: cleanup rcu_preempt_deferred_qs() Lai Jiangshan
2019-10-31 14:10   ` Paul E. McKenney
2019-10-31 14:35     ` Lai Jiangshan
2019-10-31 15:07       ` Paul E. McKenney
2019-10-31 18:33         ` Lai Jiangshan
2019-10-31 22:45           ` Paul E. McKenney
2019-10-31 10:08 ` [PATCH 05/11] rcu: clean all rcu_read_unlock_special after report qs Lai Jiangshan
2019-11-01 11:54   ` Paul E. McKenney
2019-10-31 10:08 ` [PATCH 06/11] rcu: clear t->rcu_read_unlock_special in one go Lai Jiangshan
2019-11-01 12:10   ` Paul E. McKenney
2019-11-01 16:58     ` Paul E. McKenney
2019-10-31 10:08 ` [PATCH 07/11] rcu: set special.b.deferred_qs before wake_up() Lai Jiangshan
2019-10-31 10:08 ` [PATCH 08/11] rcu: don't use negative ->rcu_read_lock_nesting Lai Jiangshan
2019-11-01 12:33   ` Paul E. McKenney
2019-11-16 13:04     ` Lai Jiangshan
2019-11-17 21:53       ` Paul E. McKenney
2019-11-18  1:54         ` Lai Jiangshan
2019-11-18 14:57           ` Paul E. McKenney
2019-10-31 10:08 ` [PATCH 09/11] rcu: wrap usages of rcu_read_lock_nesting Lai Jiangshan
2019-10-31 10:08 ` [PATCH 10/11] rcu: clear the special.b.need_qs in rcu_note_context_switch() Lai Jiangshan
2019-10-31 10:08 ` [PATCH 11/11] x86,rcu: use percpu rcu_preempt_depth Lai Jiangshan
2019-11-01 12:58   ` Paul E. McKenney
2019-11-01 13:13     ` Peter Zijlstra
2019-11-01 14:30       ` Paul E. McKenney
2019-11-01 15:32         ` Lai Jiangshan
2019-11-01 16:21           ` Paul E. McKenney
2019-11-01 15:47       ` Lai Jiangshan

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