Subject: sched: Do not account rcu_preempt_depth on RT in might_sleep() From: Thomas Gleixner Date: Tue, 07 Jun 2011 09:19:06 +0200 Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.18/older/patches-4.18.7-rt5.tar.xz RT changes the rcu_preempt_depth semantics, so we cannot check for it in might_sleep(). Signed-off-by: Thomas Gleixner --- include/linux/rcupdate.h | 7 +++++++ kernel/sched/core.c | 2 +- 2 files changed, 8 insertions(+), 1 deletion(-) --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -74,6 +74,11 @@ void synchronize_rcu(void); * types of kernel builds, the rcu_read_lock() nesting depth is unknowable. */ #define rcu_preempt_depth() (current->rcu_read_lock_nesting) +#ifndef CONFIG_PREEMPT_RT_FULL +#define sched_rcu_preempt_depth() rcu_preempt_depth() +#else +static inline int sched_rcu_preempt_depth(void) { return 0; } +#endif #else /* #ifdef CONFIG_PREEMPT_RCU */ @@ -99,6 +104,8 @@ static inline int rcu_preempt_depth(void return 0; } +#define sched_rcu_preempt_depth() rcu_preempt_depth() + #endif /* #else #ifdef CONFIG_PREEMPT_RCU */ /* Internal to kernel */ --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6181,7 +6181,7 @@ void __init sched_init(void) #ifdef CONFIG_DEBUG_ATOMIC_SLEEP static inline int preempt_count_equals(int preempt_offset) { - int nested = preempt_count() + rcu_preempt_depth(); + int nested = preempt_count() + sched_rcu_preempt_depth(); return (nested == preempt_offset); }