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locking/arch: Rename set_mb() to smp_store_mb()

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Since set_mb() is really about an smp_mb() -- not a IO/DMA barrier
like mb() rename it to match the recent smp_load_acquire() and
smp_store_release().

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2015-05-12 10:51:55 +02:00 committed by Ingo Molnar
parent ab3f02fc23
commit b92b8b35a2
18 changed files with 29 additions and 33 deletions
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6
Documentation/memory-barriers.txt
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@ -1662,7 +1662,7 @@ CPU from reordering them.
There are some more advanced barrier functions:
(*) set_mb(var, value)
(*) smp_store_mb(var, value)
This assigns the value to the variable and then inserts a full memory
barrier after it, depending on the function. It isn't guaranteed to
@ -1975,7 +1975,7 @@ after it has altered the task state:
CPU 1
===============================
set_current_state();
set_mb();
smp_store_mb();
STORE current->state
<general barrier>
LOAD event_indicated
@ -2016,7 +2016,7 @@ between the STORE to indicate the event and the STORE to set TASK_RUNNING:
CPU 1 CPU 2
=============================== ===============================
set_current_state(); STORE event_indicated
set_mb(); wake_up();
smp_store_mb(); wake_up();
STORE current->state <write barrier>
<general barrier> STORE current->state
LOAD event_indicated

2
arch/arm/include/asm/barrier.h
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@ -81,7 +81,7 @@ do { \
#define read_barrier_depends() do { } while(0)
#define smp_read_barrier_depends() do { } while(0)
#define set_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0)
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0)
#define smp_mb__before_atomic() smp_mb()
#define smp_mb__after_atomic() smp_mb()

2
arch/arm64/include/asm/barrier.h
View File

@ -114,7 +114,7 @@ do { \
#define read_barrier_depends() do { } while(0)
#define smp_read_barrier_depends() do { } while(0)
#define set_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0)
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0)
#define nop() asm volatile("nop");
#define smp_mb__before_atomic() smp_mb()

7
arch/ia64/include/asm/barrier.h
View File

@ -77,12 +77,7 @@ do { \
___p1; \
})
/*
* XXX check on this ---I suspect what Linus really wants here is
* acquire vs release semantics but we can't discuss this stuff with
* Linus just yet. Grrr...
*/
#define set_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0)
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0)
/*
* The group barrier in front of the rsm & ssm are necessary to ensure

2
arch/metag/include/asm/barrier.h
View File

@ -84,7 +84,7 @@ static inline void fence(void)
#define read_barrier_depends() do { } while (0)
#define smp_read_barrier_depends() do { } while (0)
#define set_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0)
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0)
#define smp_store_release(p, v) \
do { \

2
arch/mips/include/asm/barrier.h
View File

@ -112,7 +112,7 @@
#define __WEAK_LLSC_MB " \n"
#endif
#define set_mb(var, value) \
#define smp_store_mb(var, value) \
do { WRITE_ONCE(var, value); smp_mb(); } while (0)
#define smp_llsc_mb() __asm__ __volatile__(__WEAK_LLSC_MB : : :"memory")

2
arch/powerpc/include/asm/barrier.h
View File

@ -34,7 +34,7 @@
#define rmb() __asm__ __volatile__ ("sync" : : : "memory")
#define wmb() __asm__ __volatile__ ("sync" : : : "memory")
#define set_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0)
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0)
#ifdef __SUBARCH_HAS_LWSYNC
# define SMPWMB LWSYNC

2
arch/s390/include/asm/barrier.h
View File

@ -36,7 +36,7 @@
#define smp_mb__before_atomic() smp_mb()
#define smp_mb__after_atomic() smp_mb()
#define set_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0)
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0)
#define smp_store_release(p, v) \
do { \

2
arch/sh/include/asm/barrier.h
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@ -32,7 +32,7 @@
#define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop")
#endif
#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)
#define smp_store_mb(var, value) do { (void)xchg(&var, value); } while (0)
#include <asm-generic/barrier.h>

2
arch/sparc/include/asm/barrier_64.h
View File

@ -40,7 +40,7 @@ do { __asm__ __volatile__("ba,pt %%xcc, 1f\n\t" \
#define dma_rmb() rmb()
#define dma_wmb() wmb()
#define set_mb(__var, __value) \
#define smp_store_mb(__var, __value) \
do { WRITE_ONCE(__var, __value); membar_safe("#StoreLoad"); } while(0)
#ifdef CONFIG_SMP

4
arch/x86/include/asm/barrier.h
View File

@ -35,12 +35,12 @@
#define smp_mb() mb()
#define smp_rmb() dma_rmb()
#define smp_wmb() barrier()
#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)
#define smp_store_mb(var, value) do { (void)xchg(&var, value); } while (0)
#else /* !SMP */
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
#define set_mb(var, value) do { WRITE_ONCE(var, value); barrier(); } while (0)
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); barrier(); } while (0)
#endif /* SMP */
#define read_barrier_depends() do { } while (0)

3
arch/x86/um/asm/barrier.h
View File

@ -39,7 +39,8 @@
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
#define set_mb(var, value) do { WRITE_ONCE(var, value); barrier(); } while (0)
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); barrier(); } while (0)
#define read_barrier_depends() do { } while (0)
#define smp_read_barrier_depends() do { } while (0)

6
fs/select.c
View File

@ -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_mb() 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_mb() 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_mb(pwq->triggered, 0);
return rc;
}

4
include/asm-generic/barrier.h
View File

@ -66,8 +66,8 @@
#define smp_read_barrier_depends() do { } while (0)
#endif
#ifndef set_mb
#define set_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0)
#ifndef smp_store_mb
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0)
#endif
#ifndef smp_mb__before_atomic

8
include/linux/sched.h
View File

@ -252,7 +252,7 @@ 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_mb((tsk)->state, (state_value)); \
} while (0)
/*
@ -274,7 +274,7 @@ extern char ___assert_task_state[1 - 2*!!(
#define set_current_state(state_value) \
do { \
current->task_state_change = _THIS_IP_; \
set_mb(current->state, (state_value)); \
smp_store_mb(current->state, (state_value)); \
} while (0)
#else
@ -282,7 +282,7 @@ 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_mb((tsk)->state, (state_value))
/*
* set_current_state() includes a barrier so that the write of current->state
@ -298,7 +298,7 @@ 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_mb(current->state, (state_value))
#endif

2
kernel/futex.c
View File

@ -2055,7 +2055,7 @@ 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
* wake it. set_current_state() is implemented using smp_store_mb() and
* queue_me() calls spin_unlock() upon completion, both serializing
* access to the hash list and forcing another memory barrier.
*/

2
kernel/locking/qspinlock_paravirt.h
View File

@ -175,7 +175,7 @@ static void pv_wait_node(struct mcs_spinlock *node)
*
* Matches the xchg() from pv_kick_node().
*/
set_mb(pn->state, vcpu_halted);
smp_store_mb(pn->state, vcpu_halted);
if (!READ_ONCE(node->locked))
pv_wait(&pn->state, vcpu_halted);

4
kernel/sched/wait.c
View File

@ -341,7 +341,7 @@ long wait_woken(wait_queue_t *wait, unsigned mode, long timeout)
* condition being true _OR_ WQ_FLAG_WOKEN such that we will not miss
* an event.
*/
set_mb(wait->flags, wait->flags & ~WQ_FLAG_WOKEN); /* B */
smp_store_mb(wait->flags, wait->flags & ~WQ_FLAG_WOKEN); /* B */
return timeout;
}
@ -354,7 +354,7 @@ int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
* doesn't imply write barrier and the users expects 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 wait_woken().
* and is paired with smp_store_mb() in wait_woken().
*/
smp_wmb(); /* C */
wait->flags |= WQ_FLAG_WOKEN;