35 lines
1.0 KiB
Diff
35 lines
1.0 KiB
Diff
From 939a22067d292bb22eb0d6c7e8427d626fb297ea Mon Sep 17 00:00:00 2001
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Wed, 7 Mar 2012 20:51:03 +0100
|
|
Subject: [PATCH 261/267] 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
|
|
---
|
|
include/linux/delay.h | 6 ++++++
|
|
1 file changed, 6 insertions(+)
|
|
|
|
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) */
|
|
--
|
|
1.7.10
|
|
|