diff options
| -rw-r--r-- | CHANGES | 1 | ||||
| -rw-r--r-- | src/gpgpusim_entrypoint.cc | 25 | ||||
| -rw-r--r-- | src/stream_manager.cc | 18 | ||||
| -rw-r--r-- | src/stream_manager.h | 2 |
4 files changed, 28 insertions, 18 deletions
@@ -38,6 +38,7 @@ Version 3.2.1+edits (development branch) versus 3.2.1 - Average/min/max per-kernel powers not being reset at kernel boundaries causing incorrect per-kernel values. - Fixed a dependency error in the src/cuda-sim Makefile. + - Fixing a source of non-determinism in GPGPU-Sim (Bug 147). Version 3.2.1 versus 3.2.0 - Added kernel name and launch uids to performance statistics log. diff --git a/src/gpgpusim_entrypoint.cc b/src/gpgpusim_entrypoint.cc index 9999bb1..20fb88e 100644 --- a/src/gpgpusim_entrypoint.cc +++ b/src/gpgpusim_entrypoint.cc @@ -115,14 +115,23 @@ void *gpgpu_sim_thread_concurrent(void*) g_the_gpu->init(); do { // check if a kernel has completed - // launch operation on device if one is pending and can be run - g_stream_manager->operation(&sim_cycles); - if( g_the_gpu->active() ) { - g_the_gpu->cycle(); - sim_cycles = true; - g_the_gpu->deadlock_check(); - } - active=g_the_gpu->active() || !g_stream_manager->empty_protected(); + // launch operation on device if one is pending and can be run + + // Need to break this loop when a kernel completes. This was a + // source of non-deterministic behaviour in GPGPU-Sim (bug 147). + // If another stream operation is available, g_the_gpu remains active, + // causing this loop to not break. If the next operation happens to be + // another kernel, the gpu is not re-initialized and the inter-kernel + // behaviour may be incorrect. + if(g_stream_manager->operation(&sim_cycles)) + break; + + if( g_the_gpu->active() ) { + g_the_gpu->cycle(); + sim_cycles = true; + g_the_gpu->deadlock_check(); + } + active=g_the_gpu->active() || !g_stream_manager->empty_protected(); } while( active ); if(g_debug_execution >= 3) { printf("GPGPU-Sim: ** STOP simulation thread (no work) **\n"); diff --git a/src/stream_manager.cc b/src/stream_manager.cc index 3b8f57f..07cd44a 100644 --- a/src/stream_manager.cc +++ b/src/stream_manager.cc @@ -197,17 +197,17 @@ stream_manager::stream_manager( gpgpu_sim *gpu, bool cuda_launch_blocking ) pthread_mutex_init(&m_lock,NULL); } -void stream_manager::operation( bool * sim) +bool stream_manager::operation( bool * sim) { - pthread_mutex_lock(&m_lock); - bool check=check_finished_kernel(); - if(check) m_gpu->print_stats(); - stream_operation op =front(); - op.do_operation( m_gpu ); - pthread_mutex_unlock(&m_lock); - //pthread_mutex_lock(&m_lock); + pthread_mutex_lock(&m_lock); + bool check=check_finished_kernel(); + if(check)m_gpu->print_stats(); + stream_operation op =front(); + op.do_operation( m_gpu ); + pthread_mutex_unlock(&m_lock); + //pthread_mutex_lock(&m_lock); // simulate a clock cycle on the GPU - + return check; } bool stream_manager::check_finished_kernel() diff --git a/src/stream_manager.h b/src/stream_manager.h index a30e21b..7275402 100644 --- a/src/stream_manager.h +++ b/src/stream_manager.h @@ -245,7 +245,7 @@ public: bool empty(); void print( FILE *fp); void push( stream_operation op ); - void operation(bool * sim); + bool operation(bool * sim); private: void print_impl( FILE *fp); |