[RFC PATCH-queue/locking/rfc 1/2] locking/mutex: Simplify some ww_mutex code in __mutex_lock_common()

[Waiman Long]

This patch removes some of the redundant ww_mutex code in
__mutex_lock_common().

Signed-off-by: Waiman Long <waiman.l...@hpe.com>
---
 kernel/locking/mutex.c |   13 ++++---------
 1 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 0f8a3e6..4a0e16e 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -559,10 +559,11 @@ __mutex_lock_common(struct mutex *lock, long state, 
unsigned int subclass,
        struct task_struct *task = current;
        struct mutex_waiter waiter;
        unsigned long flags;
+       struct ww_mutex *ww;
        int ret;
 
        if (use_ww_ctx) {
-               struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
+               ww = container_of(lock, struct ww_mutex, base);
                if (unlikely(ww_ctx == READ_ONCE(ww->ctx)))
                        return -EALREADY;
        }
@@ -573,12 +574,8 @@ __mutex_lock_common(struct mutex *lock, long state, 
unsigned int subclass,
        if (__mutex_trylock(lock) || mutex_optimistic_spin(lock, ww_ctx, 
use_ww_ctx)) {
                /* got the lock, yay! */
                lock_acquired(&lock->dep_map, ip);
-               if (use_ww_ctx) {
-                       struct ww_mutex *ww;
-                       ww = container_of(lock, struct ww_mutex, base);
-
+               if (use_ww_ctx)
                        ww_mutex_set_context_fastpath(ww, ww_ctx);
-               }
                preempt_enable();
                return 0;
        }
@@ -649,10 +646,8 @@ skip_wait:
        /* got the lock - cleanup and rejoice! */
        lock_acquired(&lock->dep_map, ip);
 
-       if (use_ww_ctx) {
-               struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
+       if (use_ww_ctx)
                ww_mutex_set_context_slowpath(ww, ww_ctx);
-       }
 
        spin_unlock_mutex(&lock->wait_lock, flags);
        preempt_enable();
-- 
1.7.1