linux/debian/patches-rt/0270-sched-core-Drop-a-preempt_disable_rt-statement.patch

From 6bcf841f99e62dd5c548e5f16bbe0f70000d41ac Mon Sep 17 00:00:00 2001
Message-Id: <6bcf841f99e62dd5c548e5f16bbe0f70000d41ac.1594742966.git.zanussi@kernel.org>
In-Reply-To: <832f7d97d6b989a5b4860dd2dbec58ad6ad5ab81.1594742966.git.zanussi@kernel.org>
References: <832f7d97d6b989a5b4860dd2dbec58ad6ad5ab81.1594742966.git.zanussi@kernel.org>
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 24 Jun 2019 19:33:16 +0200
Subject: [PATCH 270/329] sched/core: Drop a preempt_disable_rt() statement
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.132-rt59.tar.xz

[ Upstream commit 761126efdcbe3fa3e99c9079fa0ad6eca2f251f2 ]

The caller holds a lock which already disables preemption.
Drop the preempt_disable_rt() statement in get_nohz_timer_target().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/sched/core.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d25017e931c6..5bfe4eab5b0a 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -558,14 +558,11 @@ void resched_cpu(int cpu)
  */
 int get_nohz_timer_target(void)
 {
-	int i, cpu;
+	int i, cpu = smp_processor_id();
 	struct sched_domain *sd;
 
-	preempt_disable_rt();
-	cpu = smp_processor_id();
-
 	if (!idle_cpu(cpu) && housekeeping_cpu(cpu, HK_FLAG_TIMER))
-		goto preempt_en_rt;
+		return cpu;
 
 	rcu_read_lock();
 	for_each_domain(cpu, sd) {
@@ -584,8 +581,6 @@ int get_nohz_timer_target(void)
 		cpu = housekeeping_any_cpu(HK_FLAG_TIMER);
 unlock:
 	rcu_read_unlock();
-preempt_en_rt:
-	preempt_enable_rt();
 	return cpu;
 }
 
-- 
2.17.1