4.19.59-rt24-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
[ Upstream commit a71221d81cc4873891ae44f3aa02df596079b786 ]
Drop the RT fixup, the futex code will be changed to avoid the need for
the workaround.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/futex.c | 19 -------------------
1 file changed, 19 deletions(-)
diff --git a/kernel/futex.c b/kernel/futex.c
index 1d9423914bf4..54ffc25183ed 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2875,14 +2875,6 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags,
* before __rt_mutex_start_proxy_lock() is done.
*/
raw_spin_lock_irq(&q.pi_state->pi_mutex.wait_lock);
- /*
- * the migrate_disable() here disables migration in the in_atomic() fast
- * path which is enabled again in the following spin_unlock(). We have
- * one migrate_disable() pending in the slow-path which is reversed
- * after the raw_spin_unlock_irq() where we leave the atomic context.
- */
- migrate_disable();
-
spin_unlock(q.lock_ptr);
/*
* __rt_mutex_start_proxy_lock() unconditionally enqueues the @rt_waiter
@@ -2891,7 +2883,6 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags,
*/
ret = __rt_mutex_start_proxy_lock(&q.pi_state->pi_mutex, &rt_waiter, current);
raw_spin_unlock_irq(&q.pi_state->pi_mutex.wait_lock);
- migrate_enable();
if (ret) {
if (ret == 1)
@@ -3040,21 +3031,11 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
* rt_waiter. Also see the WARN in wake_futex_pi().
*/
raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
- /*
- * Magic trickery for now to make the RT migrate disable
- * logic happy. The following spin_unlock() happens with
- * interrupts disabled so the internal migrate_enable()
- * won't undo the migrate_disable() which was issued when
- * locking hb->lock.
- */
- migrate_disable();
spin_unlock(&hb->lock);
/* drops pi_state->pi_mutex.wait_lock */
ret = wake_futex_pi(uaddr, uval, pi_state);
- migrate_enable();
-
put_pi_state(pi_state);
/*
--
2.20.1
