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From: Waiman Long <Waiman.Long@hpe.com>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Ding Tianhong <dingtianhong@huawei.com>,
	Jason Low <jason.low2@hpe.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	"Paul E. McKenney" <paulmck@us.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Will Deacon <Will.Deacon@arm.com>,
	Tim Chen <tim.c.chen@linux.intel.com>,
	Imre Deak <imre.deak@intel.com>,
	Waiman Long <Waiman.Long@hpe.com>
Subject: [RFC PATCH-queue/locking/rfc 1/2] locking/mutex: Simplify some ww_mutex code in __mutex_lock_common()
Date: Fri, 26 Aug 2016 19:35:08 -0400	[thread overview]
Message-ID: <1472254509-27508-1-git-send-email-Waiman.Long@hpe.com> (raw)

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

Signed-off-by: Waiman Long <Waiman.Long@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

             reply	other threads:[~2016-08-26 23:37 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-26 23:35 Waiman Long [this message]
2016-08-26 23:35 ` [RFC PATCH-queue/locking/rfc 2/2] locking/mutex: Enable optimistic spinning of woken waiter Waiman Long
2016-08-30 15:08   ` Peter Zijlstra
2016-08-30 22:58     ` Waiman Long
2016-10-25 10:29   ` [tip:locking/core] " tip-bot for Waiman Long
2016-10-25 10:29 ` [tip:locking/core] locking/mutex: Simplify some ww_mutex code in __mutex_lock_common() tip-bot for Waiman Long

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