futexes: Clean up various details

- Remove unnecessary head variables.
- Delete unused parameter in queue_unlock().

Reviewed-by: Darren Hart <dvhart@linux.intel.com>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Scott Norton <scott.norton@hp.com>
Cc: Tom Vaden <tom.vaden@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1389569486-25487-2-git-send-email-davidlohr@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/futex.c b/kernel/futex.c
index f6ff0191ecf72aca1d42f128771af55f9c859d13..085f5fa0b3424da15208b2aeb7e23a4ab1937e3f 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -598,13 +598,10 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
 {
        struct futex_pi_state *pi_state = NULL;
        struct futex_q *this, *next;
-       struct plist_head *head;
        struct task_struct *p;
        pid_t pid = uval & FUTEX_TID_MASK;
 
-       head = &hb->chain;
-
-       plist_for_each_entry_safe(this, next, head, list) {
+       plist_for_each_entry_safe(this, next, &hb->chain, list) {
                if (match_futex(&this->key, key)) {
                        /*
                         * Another waiter already exists - bump up
@@ -986,7 +983,6 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset)
 {
        struct futex_hash_bucket *hb;
        struct futex_q *this, *next;
-       struct plist_head *head;
        union futex_key key = FUTEX_KEY_INIT;
        int ret;
 
@@ -999,9 +995,8 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset)
 
        hb = hash_futex(&key);
        spin_lock(&hb->lock);
-       head = &hb->chain;
 
-       plist_for_each_entry_safe(this, next, head, list) {
+       plist_for_each_entry_safe(this, next, &hb->chain, list) {
                if (match_futex (&this->key, &key)) {
                        if (this->pi_state || this->rt_waiter) {
                                ret = -EINVAL;
@@ -1034,7 +1029,6 @@ futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2,
 {
        union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
        struct futex_hash_bucket *hb1, *hb2;
-       struct plist_head *head;
        struct futex_q *this, *next;
        int ret, op_ret;
 
@@ -1082,9 +1076,7 @@ retry_private:
                goto retry;
        }
 
-       head = &hb1->chain;
-
-       plist_for_each_entry_safe(this, next, head, list) {
+       plist_for_each_entry_safe(this, next, &hb1->chain, list) {
                if (match_futex (&this->key, &key1)) {
                        if (this->pi_state || this->rt_waiter) {
                                ret = -EINVAL;
@@ -1097,10 +1089,8 @@ retry_private:
        }
 
        if (op_ret > 0) {
-               head = &hb2->chain;
-
                op_ret = 0;
-               plist_for_each_entry_safe(this, next, head, list) {
+               plist_for_each_entry_safe(this, next, &hb2->chain, list) {
                        if (match_futex (&this->key, &key2)) {
                                if (this->pi_state || this->rt_waiter) {
                                        ret = -EINVAL;
@@ -1270,7 +1260,6 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags,
        int drop_count = 0, task_count = 0, ret;
        struct futex_pi_state *pi_state = NULL;
        struct futex_hash_bucket *hb1, *hb2;
-       struct plist_head *head1;
        struct futex_q *this, *next;
        u32 curval2;
 
@@ -1393,8 +1382,7 @@ retry_private:
                }
        }
 
-       head1 = &hb1->chain;
-       plist_for_each_entry_safe(this, next, head1, list) {
+       plist_for_each_entry_safe(this, next, &hb1->chain, list) {
                if (task_count - nr_wake >= nr_requeue)
                        break;
 
@@ -1494,7 +1482,7 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q)
 }
 
 static inline void
-queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
+queue_unlock(struct futex_hash_bucket *hb)
        __releases(&hb->lock)
 {
        spin_unlock(&hb->lock);
@@ -1867,7 +1855,7 @@ retry_private:
        ret = get_futex_value_locked(&uval, uaddr);
 
        if (ret) {
-               queue_unlock(q, *hb);
+               queue_unlock(*hb);
 
                ret = get_user(uval, uaddr);
                if (ret)
@@ -1881,7 +1869,7 @@ retry_private:
        }
 
        if (uval != val) {
-               queue_unlock(q, *hb);
+               queue_unlock(*hb);
                ret = -EWOULDBLOCK;
        }
 
@@ -2029,7 +2017,7 @@ retry_private:
                         * Task is exiting and we just wait for the
                         * exit to complete.
                         */
-                       queue_unlock(&q, hb);
+                       queue_unlock(hb);
                        put_futex_key(&q.key);
                        cond_resched();
                        goto retry;
@@ -2081,7 +2069,7 @@ retry_private:
        goto out_put_key;
 
 out_unlock_put_key:
-       queue_unlock(&q, hb);
+       queue_unlock(hb);
 
 out_put_key:
        put_futex_key(&q.key);
@@ -2091,7 +2079,7 @@ out:
        return ret != -EINTR ? ret : -ERESTARTNOINTR;
 
 uaddr_faulted:
-       queue_unlock(&q, hb);
+       queue_unlock(hb);
 
        ret = fault_in_user_writeable(uaddr);
        if (ret)
@@ -2113,7 +2101,6 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
 {
        struct futex_hash_bucket *hb;
        struct futex_q *this, *next;
-       struct plist_head *head;
        union futex_key key = FUTEX_KEY_INIT;
        u32 uval, vpid = task_pid_vnr(current);
        int ret;
@@ -2153,9 +2140,7 @@ retry:
         * Ok, other tasks may need to be woken up - check waiters
         * and do the wakeup if necessary:
         */
-       head = &hb->chain;
-
-       plist_for_each_entry_safe(this, next, head, list) {
+       plist_for_each_entry_safe(this, next, &hb->chain, list) {
                if (!match_futex (&this->key, &key))
                        continue;
                ret = wake_futex_pi(uaddr, uval, this);