From: Thomas Gleixner Date: Tue, 9 Mar 2021 08:42:04 +0000 (+0100) Subject: tasklets: Replace barrier() with cpu_relax() in tasklet_unlock_wait() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d2da74d1278a1b51ef18beafa9da770f0db1c617;p=linux.git 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 --- diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 2b98156ec7075..d689fd7381522 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