From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Retry loops on RT might loop forever when the modifying side was preempted. Add cpu_chill() to replace cpu_relax(). cpu_chill() defaults to cpu_relax() for non RT. On RT it puts the looping task to sleep for a tick so the preempted task can make progress. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: stable-rt@xxxxxxxxxxxxxxx Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- include/linux/delay.h | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/include/linux/delay.h b/include/linux/delay.h index a6ecb34..e23a7c0 100644 --- a/include/linux/delay.h +++ b/include/linux/delay.h @@ -52,4 +52,10 @@ static inline void ssleep(unsigned int seconds) msleep(seconds * 1000); } +#ifdef CONFIG_PREEMPT_RT_FULL +# define cpu_chill() msleep(1) +#else +# define cpu_chill() cpu_relax() +#endif + #endif /* defined(_LINUX_DELAY_H) */ -- 1.7.8.3 -- To unsubscribe from this list: send the line "unsubscribe stable-rt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
