[RFC patch 1/5] futex: Misc cleanups

From: Thomas Gleixner
Date: Mon Nov 25 2013 - 15:59:38 EST


From: Jason Low <jason.low2@xxxxxx>

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

Signed-off-by: Jason Low <jason.low2@xxxxxx>
Signed-off-by: Davidlohr Bueso <davidlohr@xxxxxx>
Link: http://lkml.kernel.org/r/1385168197-8612-2-git-send-email-davidlohr@xxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/futex.c | 40 ++++++++++++----------------------------
1 file changed, 12 insertions(+), 28 deletions(-)

Index: linux-2.6/kernel/futex.c
===================================================================
--- linux-2.6.orig/kernel/futex.c
+++ linux-2.6/kernel/futex.c
@@ -597,13 +597,10 @@ lookup_pi_state(u32 uval, struct futex_h
{
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
@@ -985,7 +982,6 @@ futex_wake(u32 __user *uaddr, unsigned i
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
- struct plist_head *head;
union futex_key key = FUTEX_KEY_INIT;
int ret;

@@ -998,9 +994,8 @@ futex_wake(u32 __user *uaddr, unsigned i

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;
@@ -1033,7 +1028,6 @@ futex_wake_op(u32 __user *uaddr1, unsign
{
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;

@@ -1081,9 +1075,7 @@ 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;
@@ -1096,10 +1088,8 @@ 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;
@@ -1269,7 +1259,6 @@ static int futex_requeue(u32 __user *uad
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;

@@ -1392,8 +1381,7 @@ 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;

@@ -1492,8 +1480,7 @@ static inline struct futex_hash_bucket *
return hb;
}

-static inline void
-queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
+static inline void queue_unlock(struct futex_hash_bucket *hb)
__releases(&hb->lock)
{
spin_unlock(&hb->lock);
@@ -1866,7 +1853,7 @@ 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)
@@ -1880,7 +1867,7 @@ retry_private:
}

if (uval != val) {
- queue_unlock(q, *hb);
+ queue_unlock(*hb);
ret = -EWOULDBLOCK;
}

@@ -2028,7 +2015,7 @@ 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;
@@ -2080,7 +2067,7 @@ 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);
@@ -2090,7 +2077,7 @@ out:
return ret != -EINTR ? ret : -ERESTARTNOINTR;

uaddr_faulted:
- queue_unlock(&q, hb);
+ queue_unlock(hb);

ret = fault_in_user_writeable(uaddr);
if (ret)
@@ -2112,7 +2099,6 @@ static int futex_unlock_pi(u32 __user *u
{
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;
@@ -2152,9 +2138,7 @@ 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);


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