diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2012-03-07 20:51:03 +0100 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2012-03-14 10:50:17 -0500 |
| commit | a6aca86c866f1f509772e276bccbb5472f61bb5c (patch) | |
| tree | 95d615a054ba9a4329bedf92eb281e4a094eb77e | |
| parent | 990011db2733e6258e9da6180c55598c782b03e1 (diff) | |
rt: Introduce cpu_chill()
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@linutronix.de>
Cc: stable-rt@vger.kernel.org
| -rw-r--r-- | 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 a6ecb34cf547..e23a7c021eeb 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) */ |