[PATCH RT 2/6] kernel: migrate_disable() do fastpath in atomic & irqs-off

From: Sebastian Andrzej Siewior
Date: Fri Feb 12 2016 - 18:04:56 EST


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>
---
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 1217926b500d..40c1e29416c0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3157,7 +3157,7 @@ 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
@@ -3188,7 +3188,7 @@ void migrate_enable(void)
{
struct task_struct *p = current;

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