From: Sebastian Andrzej Siewior Date: Tue, 9 Feb 2016 18:18:01 +0100 Subject: kernel: migrate_disable() do fastpath in atomic & irqs-off Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.8/older/patches-4.8.14-rt9.tar.xz 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 --- kernel/sched/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3293,7 +3293,7 @@ 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 @@ -3320,7 +3320,7 @@ 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