From d2da74d1278a1b51ef18beafa9da770f0db1c617 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 9 Mar 2021 09:42:04 +0100 Subject: tasklets: Replace barrier() with cpu_relax() in tasklet_unlock_wait() 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 Tested-by: Sebastian Andrzej Siewior Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20210309084241.249343366@linutronix.de --- include/linux/interrupt.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 2b98156ec707..d689fd738152 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -672,7 +672,8 @@ static inline void tasklet_unlock(struct tasklet_struct *t) 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 -- cgit v1.2.3-59-g8ed1b