[PATCH RT 07/16] sched/core: Drop a preempt_disable_rt() statement

From: Steven Rostedt
Date: Fri Jul 19 2019 - 17:50:47 EST


4.19.59-rt24-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

[ 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@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
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 91a9b2556fb0..1b2503b87473 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;
}

--
2.20.1