[patch 17/19] softirq: Replace barrier() with cpu_relax() in tasklet_unlock_wait()
From: Thomas Gleixner <hidden>
Date: 2020-11-13 14:25:00
Also in:
linux-sh, linux-um, lkml
From: Thomas Gleixner <hidden>
Date: 2020-11-13 14:25:00
Also in:
linux-sh, linux-um, lkml
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 <redacted> --- include/linux/interrupt.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- 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
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