[PATCH RT 11/19] sched/core: Drop a preempt_disable_rt() statement

From: zanussi
Date: Thu Aug 08 2019 - 15:53:28 EST


From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

v4.14.137-rt65-rc1 stable review patch.
If anyone has any objections, please let me know.

-----------


[ 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: Tom Zanussi <zanussi@xxxxxxxxxx>

Conflicts:
kernel/sched/core.c
---
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 7d2cc0715114..17da1c1aba56 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -583,14 +583,11 @@ 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) && is_housekeeping_cpu(cpu))
- goto preempt_en_rt;
+ return cpu;

rcu_read_lock();
for_each_domain(cpu, sd) {
@@ -609,8 +606,6 @@ int get_nohz_timer_target(void)
cpu = housekeeping_any_cpu();
unlock:
rcu_read_unlock();
-preempt_en_rt:
- preempt_enable_rt();
return cpu;
}

--
2.14.1