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| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2015-03-06 13:20:44 +0100 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2015-03-06 13:20:44 +0100 |
| commit | da06fe948c0878057e5f563ebd3dfe40c0f1b0d2 (patch) | |
| tree | 1cdcc2be8050fe8584d49bd92c36d76b2a4c5620 /cpukit | |
| parent | bsps: Use interrupt lock for interrupt server (diff) | |
| download | rtems-da06fe948c0878057e5f563ebd3dfe40c0f1b0d2.tar.bz2 | |
score: Fix SMP lock implementation
See also:
https://nahratzah.wordpress.com/2012/10/12/a-trivial-fair-spinlock/
http://concurrencyfreaks.blogspot.de/2014/05/relaxed-atomics-optimizations-for.html
Diffstat (limited to 'cpukit')
| -rw-r--r-- | cpukit/score/include/rtems/score/atomic.h | 2 | ||||
| -rw-r--r-- | cpukit/score/include/rtems/score/cpustdatomic.h | 6 | ||||
| -rw-r--r-- | cpukit/score/include/rtems/score/smplock.h | 2 |
3 files changed, 9 insertions, 1 deletions
diff --git a/cpukit/score/include/rtems/score/atomic.h b/cpukit/score/include/rtems/score/atomic.h index cb09c95156..0cf3e990c0 100644 --- a/cpukit/score/include/rtems/score/atomic.h +++ b/cpukit/score/include/rtems/score/atomic.h @@ -50,6 +50,8 @@ typedef CPU_atomic_Order Atomic_Order; #define ATOMIC_ORDER_RELEASE CPU_ATOMIC_ORDER_RELEASE +#define ATOMIC_ORDER_ACQ_REL CPU_ATOMIC_ORDER_ACQ_REL + #define ATOMIC_ORDER_SEQ_CST CPU_ATOMIC_ORDER_SEQ_CST #define ATOMIC_INITIALIZER_UINT( value ) CPU_ATOMIC_INITIALIZER_UINT( value ) diff --git a/cpukit/score/include/rtems/score/cpustdatomic.h b/cpukit/score/include/rtems/score/cpustdatomic.h index 3f7c14f320..d27c75f381 100644 --- a/cpukit/score/include/rtems/score/cpustdatomic.h +++ b/cpukit/score/include/rtems/score/cpustdatomic.h @@ -56,6 +56,8 @@ typedef std::memory_order CPU_atomic_Order; #define CPU_ATOMIC_ORDER_RELEASE std::memory_order_release +#define CPU_ATOMIC_ORDER_ACQ_REL std::memory_order_acq_rel + #define CPU_ATOMIC_ORDER_SEQ_CST std::memory_order_seq_cst #define CPU_ATOMIC_INITIALIZER_UINT( value ) ATOMIC_VAR_INIT( value ) @@ -85,6 +87,8 @@ typedef memory_order CPU_atomic_Order; #define CPU_ATOMIC_ORDER_RELEASE memory_order_release +#define CPU_ATOMIC_ORDER_ACQ_REL memory_order_acq_rel + #define CPU_ATOMIC_ORDER_SEQ_CST memory_order_seq_cst #define CPU_ATOMIC_INITIALIZER_UINT( value ) ATOMIC_VAR_INIT( value ) @@ -114,6 +118,8 @@ typedef int CPU_atomic_Order; #define CPU_ATOMIC_ORDER_RELEASE 3 +#define CPU_ATOMIC_ORDER_ACQ_REL 4 + #define CPU_ATOMIC_ORDER_SEQ_CST 5 #define CPU_ATOMIC_INITIALIZER_UINT( value ) ( value ) diff --git a/cpukit/score/include/rtems/score/smplock.h b/cpukit/score/include/rtems/score/smplock.h index cc54c694df..364a722828 100644 --- a/cpukit/score/include/rtems/score/smplock.h +++ b/cpukit/score/include/rtems/score/smplock.h @@ -280,7 +280,7 @@ static inline void _SMP_ticket_lock_Acquire( #endif my_ticket = - _Atomic_Fetch_add_uint( &lock->next_ticket, 1U, ATOMIC_ORDER_RELAXED ); + _Atomic_Fetch_add_uint( &lock->next_ticket, 1U, ATOMIC_ORDER_ACQ_REL ); #if defined( RTEMS_PROFILING ) now_serving = |