[PATCH -v5 11/14] futex,rt_mutex: Introduce rt_mutex_init_waiter()

From: Peter Zijlstra
Date: Sat Mar 04 2017 - 05:07:15 EST


Since there's already two copies of this code, introduce a helper now
before we get a third instance.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/futex.c | 5 +----
kernel/locking/rtmutex.c | 12 +++++++++---
kernel/locking/rtmutex_common.h | 1 +
3 files changed, 11 insertions(+), 7 deletions(-)

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2939,10 +2939,7 @@ static int futex_wait_requeue_pi(u32 __u
* The waiter is allocated on our stack, manipulated by the requeue
* code while we sleep on uaddr.
*/
- debug_rt_mutex_init_waiter(&rt_waiter);
- RB_CLEAR_NODE(&rt_waiter.pi_tree_entry);
- RB_CLEAR_NODE(&rt_waiter.tree_entry);
- rt_waiter.task = NULL;
+ rt_mutex_init_waiter(&rt_waiter);

ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, VERIFY_WRITE);
if (unlikely(ret != 0))
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1151,6 +1151,14 @@ void rt_mutex_adjust_pi(struct task_stru
next_lock, NULL, task);
}

+void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
+{
+ debug_rt_mutex_init_waiter(waiter);
+ RB_CLEAR_NODE(&waiter->pi_tree_entry);
+ RB_CLEAR_NODE(&waiter->tree_entry);
+ waiter->task = NULL;
+}
+
/**
* __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
* @lock: the rt_mutex to take
@@ -1233,9 +1241,7 @@ rt_mutex_slowlock(struct rt_mutex *lock,
unsigned long flags;
int ret = 0;

- debug_rt_mutex_init_waiter(&waiter);
- RB_CLEAR_NODE(&waiter.pi_tree_entry);
- RB_CLEAR_NODE(&waiter.tree_entry);
+ rt_mutex_init_waiter(&waiter);

/*
* Technically we could use raw_spin_[un]lock_irq() here, but this can
--- a/kernel/locking/rtmutex_common.h
+++ b/kernel/locking/rtmutex_common.h
@@ -102,6 +102,7 @@ extern void rt_mutex_init_proxy_locked(s
struct task_struct *proxy_owner);
extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
struct task_struct *proxy_owner);
+extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task);