[patch V4 58/68] futex: Remove bogus condition for requeue PI

Thomas Gleixner
2021-08-11T12:27:11Z

For requeue PI it's required to establish PI state for the PI futex to
which waiters are requeued. This either acquires the user space futex on
behalf of the top most waiter on the inner 'waitqueue' futex or attaches to
the PI state of an existing waiter or creates on attached to the owner of
the futex.

This code can retry in case of failure, but retry can never happen when the
pi state was successfully created. The condition to run this code is:

(task_count - nr_wake) < nr_requeue

which is always true because:

task_count = 0
nr_wake = 1
nr_requeue >= 0

Remove it all together.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
V4: New patch
---
kernel/futex.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2000,7 +2000,7 @@ static int futex_requeue(u32 __user *uad
}
}

- if (requeue_pi && (task_count - nr_wake < nr_requeue)) {
+ if (requeue_pi) {
struct task_struct *exiting = NULL;

/*