Re: [RFC PATCH] set_mb: Use smp_store_release() instead of set_mb()

2014-12-01 Thread Paul E. McKenney 
On Wed, Nov 26, 2014 at 11:57:36AM -0500, Pranith Kumar wrote:
> set_mb() and smp_store_release() perform the same function. Also there are 
> only
> a few users of set_mb(). We can convert these users to use smp_store_release()
> and delete the set_mb() definition.
> 
> The following patch changes the users and if this is OK I will go ahead and
> delete the set_mb() definition. Comments and suggestions welcome.

The set_mb() and smp_store_release() operations are not quite identical:

#define set_mb(var, value) do { var = value; smp_mb(); } while (0)

#define smp_store_release(p, v) \
do {\
compiletime_assert_atomic_type(*p); \
smp_mb();   \
ACCESS_ONCE(*p) = (v);  \
} while (0)

Note that set_mb() has the barrier -after- the store, but smp_store_release()
has the barrier -before- the store.

Thanx, Paul

> Thanks!
> Pranith
> 
> Signed-off-by: Pranith Kumar 
> ---
>  fs/select.c   |  6 +++---
>  include/linux/sched.h | 14 +++---
>  kernel/futex.c|  4 ++--
>  kernel/sched/wait.c   |  4 ++--
>  4 files changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/fs/select.c b/fs/select.c
> index 467bb1c..959a908 100644
> --- a/fs/select.c
> +++ b/fs/select.c
> @@ -189,7 +189,7 @@ static int __pollwake(wait_queue_t *wait, unsigned mode, 
> int sync, void *key)
>* doesn't imply write barrier and the users expect write
>* barrier semantics on wakeup functions.  The following
>* smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
> -  * and is paired with set_mb() in poll_schedule_timeout.
> +  * and is paired with smp_store_release() in poll_schedule_timeout.
>*/
>   smp_wmb();
>   pwq->triggered = 1;
> @@ -244,7 +244,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
> state,
>   /*
>* Prepare for the next iteration.
>*
> -  * The following set_mb() serves two purposes.  First, it's
> +  * The following smp_store_release() serves two purposes.  First, it's
>* the counterpart rmb of the wmb in pollwake() such that data
>* written before wake up is always visible after wake up.
>* Second, the full barrier guarantees that triggered clearing
> @@ -252,7 +252,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
> state,
>* this problem doesn't exist for the first iteration as
>* add_wait_queue() has full barrier semantics.
>*/
> - set_mb(pwq->triggered, 0);
> + smp_store_release(pwq->triggered, 0);
> 
>   return rc;
>  }
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 8db31ef..4621d0b 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -253,7 +253,7 @@ extern char ___assert_task_state[1 - 2*!!(
>  #define set_task_state(tsk, state_value) \
>   do {\
>   (tsk)->task_state_change = _THIS_IP_;   \
> - set_mb((tsk)->state, (state_value));\
> + smp_store_release((tsk)->state, (state_value)); \
>   } while (0)
> 
>  /*
> @@ -272,10 +272,10 @@ extern char ___assert_task_state[1 - 2*!!(
>   current->task_state_change = _THIS_IP_; \
>   current->state = (state_value); \
>   } while (0)
> -#define set_current_state(state_value)   \
> - do {\
> - current->task_state_change = _THIS_IP_; \
> - set_mb(current->state, (state_value));  \
> +#define set_current_state(state_value)   
> \
> + do {\
> + current->task_state_change = _THIS_IP_; \
> + smp_store_release(current->state, (state_value));   \
>   } while (0)
> 
>  #else
> @@ -283,7 +283,7 @@ extern char ___assert_task_state[1 - 2*!!(
>  #define __set_task_state(tsk, state_value)   \
>   do { (tsk)->state = (state_value); } while (0)
>  #define set_task_state(tsk, state_value) \
> - set_mb((tsk)->state, (state_value))
> + smp_store_release((tsk)->state, (state_value))
> 
>  /*
>   * set_current_state() includes a barrier so that the write of current->state
> @@ -299,7 +299,7 @@ extern char ___assert_task_state[1 - 2*!!(
>  #define __set_current_state(state_value) \
>   do { current->state = (state_value); } while (0)
>  #define set_current_state(state_value)   \
> - set_mb(current->state, (state_value))
> + smp_store_release(current->state,

Re: [RFC PATCH] set_mb: Use smp_store_release() instead of set_mb()

2014-12-01 Thread Paul E. McKenney 
On Wed, Nov 26, 2014 at 11:57:36AM -0500, Pranith Kumar wrote:
 set_mb() and smp_store_release() perform the same function. Also there are 
 only
 a few users of set_mb(). We can convert these users to use smp_store_release()
 and delete the set_mb() definition.
 
 The following patch changes the users and if this is OK I will go ahead and
 delete the set_mb() definition. Comments and suggestions welcome.

The set_mb() and smp_store_release() operations are not quite identical:

#define set_mb(var, value) do { var = value; smp_mb(); } while (0)

#define smp_store_release(p, v) \
do {\
compiletime_assert_atomic_type(*p); \
smp_mb();   \
ACCESS_ONCE(*p) = (v);  \
} while (0)

Note that set_mb() has the barrier -after- the store, but smp_store_release()
has the barrier -before- the store.

Thanx, Paul

 Thanks!
 Pranith
 
 Signed-off-by: Pranith Kumar bobby.pr...@gmail.com
 ---
  fs/select.c   |  6 +++---
  include/linux/sched.h | 14 +++---
  kernel/futex.c|  4 ++--
  kernel/sched/wait.c   |  4 ++--
  4 files changed, 14 insertions(+), 14 deletions(-)
 
 diff --git a/fs/select.c b/fs/select.c
 index 467bb1c..959a908 100644
 --- a/fs/select.c
 +++ b/fs/select.c
 @@ -189,7 +189,7 @@ static int __pollwake(wait_queue_t *wait, unsigned mode, 
 int sync, void *key)
* doesn't imply write barrier and the users expect write
* barrier semantics on wakeup functions.  The following
* smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
 -  * and is paired with set_mb() in poll_schedule_timeout.
 +  * and is paired with smp_store_release() in poll_schedule_timeout.
*/
   smp_wmb();
   pwq-triggered = 1;
 @@ -244,7 +244,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
 state,
   /*
* Prepare for the next iteration.
*
 -  * The following set_mb() serves two purposes.  First, it's
 +  * The following smp_store_release() serves two purposes.  First, it's
* the counterpart rmb of the wmb in pollwake() such that data
* written before wake up is always visible after wake up.
* Second, the full barrier guarantees that triggered clearing
 @@ -252,7 +252,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
 state,
* this problem doesn't exist for the first iteration as
* add_wait_queue() has full barrier semantics.
*/
 - set_mb(pwq-triggered, 0);
 + smp_store_release(pwq-triggered, 0);
 
   return rc;
  }
 diff --git a/include/linux/sched.h b/include/linux/sched.h
 index 8db31ef..4621d0b 100644
 --- a/include/linux/sched.h
 +++ b/include/linux/sched.h
 @@ -253,7 +253,7 @@ extern char ___assert_task_state[1 - 2*!!(
  #define set_task_state(tsk, state_value) \
   do {\
   (tsk)-task_state_change = _THIS_IP_;   \
 - set_mb((tsk)-state, (state_value));\
 + smp_store_release((tsk)-state, (state_value)); \
   } while (0)
 
  /*
 @@ -272,10 +272,10 @@ extern char ___assert_task_state[1 - 2*!!(
   current-task_state_change = _THIS_IP_; \
   current-state = (state_value); \
   } while (0)
 -#define set_current_state(state_value)   \
 - do {\
 - current-task_state_change = _THIS_IP_; \
 - set_mb(current-state, (state_value));  \
 +#define set_current_state(state_value)   
 \
 + do {\
 + current-task_state_change = _THIS_IP_; \
 + smp_store_release(current-state, (state_value));   \
   } while (0)
 
  #else
 @@ -283,7 +283,7 @@ extern char ___assert_task_state[1 - 2*!!(
  #define __set_task_state(tsk, state_value)   \
   do { (tsk)-state = (state_value); } while (0)
  #define set_task_state(tsk, state_value) \
 - set_mb((tsk)-state, (state_value))
 + smp_store_release((tsk)-state, (state_value))
 
  /*
   * set_current_state() includes a barrier so that the write of current-state
 @@ -299,7 +299,7 @@ extern char ___assert_task_state[1 - 2*!!(
  #define __set_current_state(state_value) \
   do { current-state = (state_value); } while (0)
  #define set_current_state(state_value)   \
 - set_mb(current-state, (state_value))
 + smp_store_release(current-state, (state_value))
 
  #endif
 
 diff --git a/kernel/futex.c b/kernel/futex.c
 index 63678b5..0604355

Re: [RFC PATCH] set_mb: Use smp_store_release() instead of set_mb()

2014-11-30 Thread Pranith Kumar 
On Wed, Nov 26, 2014 at 11:57 AM, Pranith Kumar  wrote:
> set_mb() and smp_store_release() perform the same function. Also there are 
> only
> a few users of set_mb(). We can convert these users to use smp_store_release()
> and delete the set_mb() definition.
>
> The following patch changes the users and if this is OK I will go ahead and
> delete the set_mb() definition. Comments and suggestions welcome.
>
> Thanks!
> Pranith
>
> Signed-off-by: Pranith Kumar 

Please disregard this patch. I just realized that I read the code
wrong. Sorry for the noise.

Thanks!


> ---
>  fs/select.c   |  6 +++---
>  include/linux/sched.h | 14 +++---
>  kernel/futex.c|  4 ++--
>  kernel/sched/wait.c   |  4 ++--
>  4 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/fs/select.c b/fs/select.c
> index 467bb1c..959a908 100644
> --- a/fs/select.c
> +++ b/fs/select.c
> @@ -189,7 +189,7 @@ static int __pollwake(wait_queue_t *wait, unsigned mode, 
> int sync, void *key)
>  * doesn't imply write barrier and the users expect write
>  * barrier semantics on wakeup functions.  The following
>  * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
> -* and is paired with set_mb() in poll_schedule_timeout.
> +* and is paired with smp_store_release() in poll_schedule_timeout.
>  */
> smp_wmb();
> pwq->triggered = 1;
> @@ -244,7 +244,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
> state,
> /*
>  * Prepare for the next iteration.
>  *
> -* The following set_mb() serves two purposes.  First, it's
> +* The following smp_store_release() serves two purposes.  First, it's
>  * the counterpart rmb of the wmb in pollwake() such that data
>  * written before wake up is always visible after wake up.
>  * Second, the full barrier guarantees that triggered clearing
> @@ -252,7 +252,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
> state,
>  * this problem doesn't exist for the first iteration as
>  * add_wait_queue() has full barrier semantics.
>  */
> -   set_mb(pwq->triggered, 0);
> +   smp_store_release(pwq->triggered, 0);
>
> return rc;
>  }
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 8db31ef..4621d0b 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -253,7 +253,7 @@ extern char ___assert_task_state[1 - 2*!!(
>  #define set_task_state(tsk, state_value)   \
> do {\
> (tsk)->task_state_change = _THIS_IP_;   \
> -   set_mb((tsk)->state, (state_value));\
> +   smp_store_release((tsk)->state, (state_value)); \
> } while (0)
>
>  /*
> @@ -272,10 +272,10 @@ extern char ___assert_task_state[1 - 2*!!(
> current->task_state_change = _THIS_IP_; \
> current->state = (state_value); \
> } while (0)
> -#define set_current_state(state_value) \
> -   do {\
> -   current->task_state_change = _THIS_IP_; \
> -   set_mb(current->state, (state_value));  \
> +#define set_current_state(state_value) \
> +   do {\
> +   current->task_state_change = _THIS_IP_; \
> +   smp_store_release(current->state, (state_value));   \
> } while (0)
>
>  #else
> @@ -283,7 +283,7 @@ extern char ___assert_task_state[1 - 2*!!(
>  #define __set_task_state(tsk, state_value) \
> do { (tsk)->state = (state_value); } while (0)
>  #define set_task_state(tsk, state_value)   \
> -   set_mb((tsk)->state, (state_value))
> +   smp_store_release((tsk)->state, (state_value))
>
>  /*
>   * set_current_state() includes a barrier so that the write of current->state
> @@ -299,7 +299,7 @@ extern char ___assert_task_state[1 - 2*!!(
>  #define __set_current_state(state_value)   \
> do { current->state = (state_value); } while (0)
>  #define set_current_state(state_value) \
> -   set_mb(current->state, (state_value))
> +   smp_store_release(current->state, (state_value))
>
>  #endif
>
> diff --git a/kernel/futex.c b/kernel/futex.c
> index 63678b5..0604355 100644
> --- a/kernel/futex.c
> +++ b/kernel/futex.c
> @@ -2055,8 +2055,8 @@ static void futex_wait_queue_me(struct 
> futex_hash_bucket *hb, struct futex_q *q,
>  {
> /*
>  * The task state is guaranteed to be set before another task can
> -* wake it. set_current_state() is implemented using set_mb() and
> -* queue_me() calls spin_unlock() upon completion, both serializing
> +*

Re: [RFC PATCH] set_mb: Use smp_store_release() instead of set_mb()

2014-11-30 Thread Pranith Kumar 
On Wed, Nov 26, 2014 at 11:57 AM, Pranith Kumar bobby.pr...@gmail.com wrote:
 set_mb() and smp_store_release() perform the same function. Also there are 
 only
 a few users of set_mb(). We can convert these users to use smp_store_release()
 and delete the set_mb() definition.

 The following patch changes the users and if this is OK I will go ahead and
 delete the set_mb() definition. Comments and suggestions welcome.

 Thanks!
 Pranith

 Signed-off-by: Pranith Kumar bobby.pr...@gmail.com

Please disregard this patch. I just realized that I read the code
wrong. Sorry for the noise.

Thanks!


 ---
  fs/select.c   |  6 +++---
  include/linux/sched.h | 14 +++---
  kernel/futex.c|  4 ++--
  kernel/sched/wait.c   |  4 ++--
  4 files changed, 14 insertions(+), 14 deletions(-)

 diff --git a/fs/select.c b/fs/select.c
 index 467bb1c..959a908 100644
 --- a/fs/select.c
 +++ b/fs/select.c
 @@ -189,7 +189,7 @@ static int __pollwake(wait_queue_t *wait, unsigned mode, 
 int sync, void *key)
  * doesn't imply write barrier and the users expect write
  * barrier semantics on wakeup functions.  The following
  * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
 -* and is paired with set_mb() in poll_schedule_timeout.
 +* and is paired with smp_store_release() in poll_schedule_timeout.
  */
 smp_wmb();
 pwq-triggered = 1;
 @@ -244,7 +244,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
 state,
 /*
  * Prepare for the next iteration.
  *
 -* The following set_mb() serves two purposes.  First, it's
 +* The following smp_store_release() serves two purposes.  First, it's
  * the counterpart rmb of the wmb in pollwake() such that data
  * written before wake up is always visible after wake up.
  * Second, the full barrier guarantees that triggered clearing
 @@ -252,7 +252,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
 state,
  * this problem doesn't exist for the first iteration as
  * add_wait_queue() has full barrier semantics.
  */
 -   set_mb(pwq-triggered, 0);
 +   smp_store_release(pwq-triggered, 0);

 return rc;
  }
 diff --git a/include/linux/sched.h b/include/linux/sched.h
 index 8db31ef..4621d0b 100644
 --- a/include/linux/sched.h
 +++ b/include/linux/sched.h
 @@ -253,7 +253,7 @@ extern char ___assert_task_state[1 - 2*!!(
  #define set_task_state(tsk, state_value)   \
 do {\
 (tsk)-task_state_change = _THIS_IP_;   \
 -   set_mb((tsk)-state, (state_value));\
 +   smp_store_release((tsk)-state, (state_value)); \
 } while (0)

  /*
 @@ -272,10 +272,10 @@ extern char ___assert_task_state[1 - 2*!!(
 current-task_state_change = _THIS_IP_; \
 current-state = (state_value); \
 } while (0)
 -#define set_current_state(state_value) \
 -   do {\
 -   current-task_state_change = _THIS_IP_; \
 -   set_mb(current-state, (state_value));  \
 +#define set_current_state(state_value) \
 +   do {\
 +   current-task_state_change = _THIS_IP_; \
 +   smp_store_release(current-state, (state_value));   \
 } while (0)

  #else
 @@ -283,7 +283,7 @@ extern char ___assert_task_state[1 - 2*!!(
  #define __set_task_state(tsk, state_value) \
 do { (tsk)-state = (state_value); } while (0)
  #define set_task_state(tsk, state_value)   \
 -   set_mb((tsk)-state, (state_value))
 +   smp_store_release((tsk)-state, (state_value))

  /*
   * set_current_state() includes a barrier so that the write of current-state
 @@ -299,7 +299,7 @@ extern char ___assert_task_state[1 - 2*!!(
  #define __set_current_state(state_value)   \
 do { current-state = (state_value); } while (0)
  #define set_current_state(state_value) \
 -   set_mb(current-state, (state_value))
 +   smp_store_release(current-state, (state_value))

  #endif

 diff --git a/kernel/futex.c b/kernel/futex.c
 index 63678b5..0604355 100644
 --- a/kernel/futex.c
 +++ b/kernel/futex.c
 @@ -2055,8 +2055,8 @@ static void futex_wait_queue_me(struct 
 futex_hash_bucket *hb, struct futex_q *q,
  {
 /*
  * The task state is guaranteed to be set before another task can
 -* wake it. set_current_state() is implemented using set_mb() and
 -* queue_me() calls spin_unlock() upon completion, both serializing
 +* wake it. set_current_state() is implemented using 
 smp_store_release()
 +* and

[RFC PATCH] set_mb: Use smp_store_release() instead of set_mb()

2014-11-26 Thread Pranith Kumar 
set_mb() and smp_store_release() perform the same function. Also there are only
a few users of set_mb(). We can convert these users to use smp_store_release()
and delete the set_mb() definition.

The following patch changes the users and if this is OK I will go ahead and
delete the set_mb() definition. Comments and suggestions welcome.

Thanks!
Pranith

Signed-off-by: Pranith Kumar 
---
 fs/select.c   |  6 +++---
 include/linux/sched.h | 14 +++---
 kernel/futex.c|  4 ++--
 kernel/sched/wait.c   |  4 ++--
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/fs/select.c b/fs/select.c
index 467bb1c..959a908 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -189,7 +189,7 @@ static int __pollwake(wait_queue_t *wait, unsigned mode, 
int sync, void *key)
 * doesn't imply write barrier and the users expect write
 * barrier semantics on wakeup functions.  The following
 * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
-* and is paired with set_mb() in poll_schedule_timeout.
+* and is paired with smp_store_release() in poll_schedule_timeout.
 */
smp_wmb();
pwq->triggered = 1;
@@ -244,7 +244,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
state,
/*
 * Prepare for the next iteration.
 *
-* The following set_mb() serves two purposes.  First, it's
+* The following smp_store_release() serves two purposes.  First, it's
 * the counterpart rmb of the wmb in pollwake() such that data
 * written before wake up is always visible after wake up.
 * Second, the full barrier guarantees that triggered clearing
@@ -252,7 +252,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
state,
 * this problem doesn't exist for the first iteration as
 * add_wait_queue() has full barrier semantics.
 */
-   set_mb(pwq->triggered, 0);
+   smp_store_release(pwq->triggered, 0);
 
return rc;
 }
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8db31ef..4621d0b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -253,7 +253,7 @@ extern char ___assert_task_state[1 - 2*!!(
 #define set_task_state(tsk, state_value)   \
do {\
(tsk)->task_state_change = _THIS_IP_;   \
-   set_mb((tsk)->state, (state_value));\
+   smp_store_release((tsk)->state, (state_value)); \
} while (0)
 
 /*
@@ -272,10 +272,10 @@ extern char ___assert_task_state[1 - 2*!!(
current->task_state_change = _THIS_IP_; \
current->state = (state_value); \
} while (0)
-#define set_current_state(state_value) \
-   do {\
-   current->task_state_change = _THIS_IP_; \
-   set_mb(current->state, (state_value));  \
+#define set_current_state(state_value) \
+   do {\
+   current->task_state_change = _THIS_IP_; \
+   smp_store_release(current->state, (state_value));   \
} while (0)
 
 #else
@@ -283,7 +283,7 @@ extern char ___assert_task_state[1 - 2*!!(
 #define __set_task_state(tsk, state_value) \
do { (tsk)->state = (state_value); } while (0)
 #define set_task_state(tsk, state_value)   \
-   set_mb((tsk)->state, (state_value))
+   smp_store_release((tsk)->state, (state_value))
 
 /*
  * set_current_state() includes a barrier so that the write of current->state
@@ -299,7 +299,7 @@ extern char ___assert_task_state[1 - 2*!!(
 #define __set_current_state(state_value)   \
do { current->state = (state_value); } while (0)
 #define set_current_state(state_value) \
-   set_mb(current->state, (state_value))
+   smp_store_release(current->state, (state_value))
 
 #endif
 
diff --git a/kernel/futex.c b/kernel/futex.c
index 63678b5..0604355 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2055,8 +2055,8 @@ static void futex_wait_queue_me(struct futex_hash_bucket 
*hb, struct futex_q *q,
 {
/*
 * The task state is guaranteed to be set before another task can
-* wake it. set_current_state() is implemented using set_mb() and
-* queue_me() calls spin_unlock() upon completion, both serializing
+* wake it. set_current_state() is implemented using smp_store_release()
+* and queue_me() calls spin_unlock() upon completion, both serializing
 * access to the hash list and forcing another memory barrier.
 */
set_current_state(TASK_INTERRUPTIBLE);
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 852143a..7d990c0 100644
---

[RFC PATCH] set_mb: Use smp_store_release() instead of set_mb()

2014-11-26 Thread Pranith Kumar 
set_mb() and smp_store_release() perform the same function. Also there are only
a few users of set_mb(). We can convert these users to use smp_store_release()
and delete the set_mb() definition.

The following patch changes the users and if this is OK I will go ahead and
delete the set_mb() definition. Comments and suggestions welcome.

Thanks!
Pranith

Signed-off-by: Pranith Kumar bobby.pr...@gmail.com
---
 fs/select.c   |  6 +++---
 include/linux/sched.h | 14 +++---
 kernel/futex.c|  4 ++--
 kernel/sched/wait.c   |  4 ++--
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/fs/select.c b/fs/select.c
index 467bb1c..959a908 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -189,7 +189,7 @@ static int __pollwake(wait_queue_t *wait, unsigned mode, 
int sync, void *key)
 * doesn't imply write barrier and the users expect write
 * barrier semantics on wakeup functions.  The following
 * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
-* and is paired with set_mb() in poll_schedule_timeout.
+* and is paired with smp_store_release() in poll_schedule_timeout.
 */
smp_wmb();
pwq-triggered = 1;
@@ -244,7 +244,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
state,
/*
 * Prepare for the next iteration.
 *
-* The following set_mb() serves two purposes.  First, it's
+* The following smp_store_release() serves two purposes.  First, it's
 * the counterpart rmb of the wmb in pollwake() such that data
 * written before wake up is always visible after wake up.
 * Second, the full barrier guarantees that triggered clearing
@@ -252,7 +252,7 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int 
state,
 * this problem doesn't exist for the first iteration as
 * add_wait_queue() has full barrier semantics.
 */
-   set_mb(pwq-triggered, 0);
+   smp_store_release(pwq-triggered, 0);
 
return rc;
 }
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8db31ef..4621d0b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -253,7 +253,7 @@ extern char ___assert_task_state[1 - 2*!!(
 #define set_task_state(tsk, state_value)   \
do {\
(tsk)-task_state_change = _THIS_IP_;   \
-   set_mb((tsk)-state, (state_value));\
+   smp_store_release((tsk)-state, (state_value)); \
} while (0)
 
 /*
@@ -272,10 +272,10 @@ extern char ___assert_task_state[1 - 2*!!(
current-task_state_change = _THIS_IP_; \
current-state = (state_value); \
} while (0)
-#define set_current_state(state_value) \
-   do {\
-   current-task_state_change = _THIS_IP_; \
-   set_mb(current-state, (state_value));  \
+#define set_current_state(state_value) \
+   do {\
+   current-task_state_change = _THIS_IP_; \
+   smp_store_release(current-state, (state_value));   \
} while (0)
 
 #else
@@ -283,7 +283,7 @@ extern char ___assert_task_state[1 - 2*!!(
 #define __set_task_state(tsk, state_value) \
do { (tsk)-state = (state_value); } while (0)
 #define set_task_state(tsk, state_value)   \
-   set_mb((tsk)-state, (state_value))
+   smp_store_release((tsk)-state, (state_value))
 
 /*
  * set_current_state() includes a barrier so that the write of current-state
@@ -299,7 +299,7 @@ extern char ___assert_task_state[1 - 2*!!(
 #define __set_current_state(state_value)   \
do { current-state = (state_value); } while (0)
 #define set_current_state(state_value) \
-   set_mb(current-state, (state_value))
+   smp_store_release(current-state, (state_value))
 
 #endif
 
diff --git a/kernel/futex.c b/kernel/futex.c
index 63678b5..0604355 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2055,8 +2055,8 @@ static void futex_wait_queue_me(struct futex_hash_bucket 
*hb, struct futex_q *q,
 {
/*
 * The task state is guaranteed to be set before another task can
-* wake it. set_current_state() is implemented using set_mb() and
-* queue_me() calls spin_unlock() upon completion, both serializing
+* wake it. set_current_state() is implemented using smp_store_release()
+* and queue_me() calls spin_unlock() upon completion, both serializing
 * access to the hash list and forcing another memory barrier.
 */
set_current_state(TASK_INTERRUPTIBLE);
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 852143a..7d990c0 100644
---