[patch V3 62/64] preempt: Adjust PREEMPT_LOCK_OFFSET for RT

Thomas Gleixner
2021-08-05T15:46:15Z

From: Thomas Gleixner <tglx@linutronix.de>

On PREEMPT_RT regular spinlocks and rwlocks are substituted with rtmutex
based constructs. spin/rwlock held regions are preemptible on PREEMPT_RT,
so PREEMPT_LOCK_OFFSET has to be 0 to make the various cond_resched_*lock()
functions work correctly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/preempt.h | 4 ++++
1 file changed, 4 insertions(+)
---
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -121,7 +121,11 @@
/*
* The preempt_count offset after spin_lock()
*/
+#if !defined(CONFIG_PREEMPT_RT)
#define PREEMPT_LOCK_OFFSET PREEMPT_DISABLE_OFFSET
+#else
+#define PREEMPT_LOCK_OFFSET 0
+#endif

/*
* The preempt_count offset needed for things like: