From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Davidlohr Bueso <davidlohr@hp.com>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
dvhart@linux.intel.com, peterz@infradead.org, tglx@linutronix.de,
efault@gmx.de, jeffm@suse.com, torvalds@linux-foundation.org,
jason.low2@hp.com, Waiman.Long@hp.com, tom.vaden@hp.com,
scott.norton@hp.com, aswin@hp.com
Subject: Re: [PATCH v5 1/4] futex: Misc cleanups
Date: Fri, 10 Jan 2014 22:43:39 -0800 [thread overview]
Message-ID: <20140111064339.GZ10038@linux.vnet.ibm.com> (raw)
In-Reply-To: <1388675120-8017-2-git-send-email-davidlohr@hp.com>
On Thu, Jan 02, 2014 at 07:05:17AM -0800, Davidlohr Bueso wrote:
> From: Jason Low <jason.low2@hp.com>
>
> - Remove unnecessary head variables.
> - Delete unused parameter in queue_unlock().
>
> Cc: Ingo Molnar <mingo@kernel.org>
> Reviewed-by: Darren Hart <dvhart@linux.intel.com>
> Acked-by: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.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>
> Signed-off-by: Jason Low <jason.low2@hp.com>
> Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> ---
> kernel/futex.c | 39 ++++++++++++---------------------------
> 1 file changed, 12 insertions(+), 27 deletions(-)
>
> diff --git a/kernel/futex.c b/kernel/futex.c
> index f6ff019..085f5fa 100644
> --- 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);
> --
> 1.8.1.4
>
next prev parent reply other threads:[~2014-01-11 6:43 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-02 15:05 [PATCH v5 0/4] futex: Wakeup optimizations Davidlohr Bueso
2014-01-02 15:05 ` [PATCH v5 1/4] futex: Misc cleanups Davidlohr Bueso
2014-01-11 6:43 ` Paul E. McKenney [this message]
2014-01-02 15:05 ` [PATCH v5 2/4] futex: Larger hash table Davidlohr Bueso
2014-01-11 7:37 ` Paul E. McKenney
2014-01-02 15:05 ` [PATCH v5 3/4] futex: Document ordering guarantees Davidlohr Bueso
2014-01-06 18:58 ` Darren Hart
2014-01-11 7:40 ` Paul E. McKenney
2014-01-02 15:05 ` [PATCH v5 4/4] futex: Avoid taking hb lock if nothing to wakeup Davidlohr Bueso
2014-01-02 19:23 ` Linus Torvalds
2014-01-02 20:59 ` Davidlohr Bueso
2014-01-06 20:56 ` Darren Hart
2014-01-06 20:52 ` Darren Hart
2014-01-07 3:29 ` Davidlohr Bueso
2014-01-07 17:40 ` Darren Hart
2014-01-11 9:49 ` Paul E. McKenney
2014-01-11 9:52 ` Paul E. McKenney
2014-01-11 18:21 ` Davidlohr Bueso
2014-01-06 0:59 ` [PATCH v5 0/4] futex: Wakeup optimizations Davidlohr Bueso
2014-01-06 1:38 ` [PATCH 5/4] futex: silence uninitialized warnings Davidlohr Bueso
2014-01-06 18:48 ` Darren Hart
2014-01-07 2:55 ` Linus Torvalds
2014-01-07 3:02 ` Davidlohr Bueso
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