[PATCH RT 09/20] kernel: migrate_disable() do fastpath in atomic & irqs-off

From: Steven Rostedt
Date: Wed Mar 02 2016 - 10:43:28 EST


3.18.27-rt27-rc1 stable review patch.
If anyone has any objections, please let me know.

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

From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

With interrupts off it makes no sense to do the long path since we can't
leave the CPU anyway. Also we might end up in a recursion with lockdep.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/sched/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8214206817f2..24c7ced53555 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2859,7 +2859,7 @@ void migrate_disable(void)
{
struct task_struct *p = current;

- if (in_atomic()) {
+ if (in_atomic() || irqs_disabled()) {
#ifdef CONFIG_SCHED_DEBUG
p->migrate_disable_atomic++;
#endif
@@ -2893,7 +2893,7 @@ void migrate_enable(void)
unsigned long flags;
struct rq *rq;

- if (in_atomic()) {
+ if (in_atomic() || irqs_disabled()) {
#ifdef CONFIG_SCHED_DEBUG
p->migrate_disable_atomic--;
#endif
--
2.7.0