diff mbox series

[17/19] softirq: Replace barrier() with cpu_relax() in tasklet_unlock_wait()

Message ID 20201113141734.660734753@linutronix.de (mailing list archive)
State Not Applicable
Headers show
Series softirq: Cleanups and RT awareness | expand

Commit Message

Thomas Gleixner Nov. 13, 2020, 2:02 p.m. UTC 
A barrier() in a tight loop which waits for something to happen on a remote
CPU is a pointless exercise. Replace it with cpu_relax() which allows HT
siblings to make progress.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 include/linux/interrupt.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -668,7 +668,8 @@  static inline void tasklet_unlock(struct
 
 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 {
-	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
+	while (test_bit(TASKLET_STATE_RUN, &(t)->state))
+		cpu_relax();
 }
 #else
 #define tasklet_trylock(t) 1