Re: [patch 07/14] tasklets: Prevent tasklet_unlock_spin_wait() deadlock on RT

[Sebastian Andrzej Siewior]

On 2021-03-09 09:42:10 [+0100], Thomas Gleixner wrote:
> tasklet_unlock_spin_wait() spin waits for the TASKLET_STATE_SCHED bit in
> the tasklet state to be cleared. This works on !RT nicely because the
…

Could you please fold this:

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 07c7329d21aa7..1c14ccd351091 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -663,15 +663,6 @@ static inline int tasklet_trylock(struct tasklet_struct *t)
 void tasklet_unlock(struct tasklet_struct *t);
 void tasklet_unlock_wait(struct tasklet_struct *t);
 
-/*
- * Do not use in new code. Waiting for tasklets from atomic contexts is
- * error prone and should be avoided.
- */
-static inline void tasklet_unlock_spin_wait(struct tasklet_struct *t)
-{
-	while (test_bit(TASKLET_STATE_RUN, &t->state))
-		cpu_relax();
-}
 #else
 static inline int tasklet_trylock(struct tasklet_struct *t) { return 1; }
 static inline void tasklet_unlock(struct tasklet_struct *t) { }
diff --git a/kernel/softirq.c b/kernel/softirq.c
index f0074f1344402..c9adc5c462485 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -830,8 +830,8 @@ EXPORT_SYMBOL(tasklet_init);
 
 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
 /*
- * Do not use in new code. There is no real reason to invoke this from
- * atomic contexts.
+ * Do not use in new code. Waiting for tasklets from atomic contexts is
+ * error prone and should be avoided.
  */
 void tasklet_unlock_spin_wait(struct tasklet_struct *t)
 {
-- 
2.30.1