Messages in this thread Patch in this message | | | Date | Wed, 17 Mar 2021 15:49:00 -0000 | From | "tip-bot2 for Thomas Gleixner" <> | Subject | [tip: irq/core] tasklets: Replace barrier() with cpu_relax() in tasklet_unlock_wait() |
| |
The following commit has been merged into the irq/core branch of tip:
Commit-ID: d2da74d1278a1b51ef18beafa9da770f0db1c617 Gitweb: https://git.kernel.org/tip/d2da74d1278a1b51ef18beafa9da770f0db1c617 Author: Thomas Gleixner <tglx@linutronix.de> AuthorDate: Tue, 09 Mar 2021 09:42:04 +01:00 Committer: Thomas Gleixner <tglx@linutronix.de> CommitterDate: Wed, 17 Mar 2021 16:33:51 +01:00
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 <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210309084241.249343366@linutronix.de
--- include/linux/interrupt.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 2b98156..d689fd7 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
| |