diff options
| -rw-r--r-- | source/blender/blenlib/BLI_task.h | 16 | ||||
| -rw-r--r-- | source/blender/blenlib/intern/task.c | 9 |
2 files changed, 24 insertions, 1 deletions
diff --git a/source/blender/blenlib/BLI_task.h b/source/blender/blenlib/BLI_task.h index b4c374d3fe7..0f78d2f4361 100644 --- a/source/blender/blenlib/BLI_task.h +++ b/source/blender/blenlib/BLI_task.h @@ -167,6 +167,17 @@ typedef struct ParallelRangeSettings { * processed. */ TaskParallelRangeFuncFinalize func_finalize; + /* Minimum allowed number of range iterators to be handled by a single + * thread. This allows to achieve following: + * - Reduce amount of threading overhead. + * - Partially occupy thread pool with ranges which are computationally + * expensive, but which are smaller than amount of available threads. + * For example, it's possible to multi-thread [0 .. 64] range into 4 + * thread which will be doing 16 iterators each. + * This is a preferred way to tell scheduler when to start threading than + * having a global use_threading switch based on just range size. + */ + int min_iter_per_thread; } ParallelRangeSettings; BLI_INLINE void BLI_parallel_range_settings_defaults( @@ -203,6 +214,11 @@ BLI_INLINE void BLI_parallel_range_settings_defaults( memset(settings, 0, sizeof(*settings)); settings->use_threading = true; settings->scheduling_mode = TASK_SCHEDULING_STATIC; + /* NOTE: Current value mimics old behavior, but it's not ideal by any + * means. Would be cool to find a common value which will work good enough + * for both static and dynamic scheduling. + */ + settings->min_iter_per_thread = 1; } #ifdef __cplusplus diff --git a/source/blender/blenlib/intern/task.c b/source/blender/blenlib/intern/task.c index f2a14aa9363..ba600be870b 100644 --- a/source/blender/blenlib/intern/task.c +++ b/source/blender/blenlib/intern/task.c @@ -1113,15 +1113,22 @@ void BLI_task_parallel_range(int start, int stop, state.iter = start; switch (settings->scheduling_mode) { case TASK_SCHEDULING_STATIC: - state.chunk_size = max_ii(1, (stop - start) / (num_tasks)); + state.chunk_size = max_ii( + settings->min_iter_per_thread, + (stop - start) / (num_tasks)); break; case TASK_SCHEDULING_DYNAMIC: + /* TODO(sergey): Make it configurable from min_iter_per_thread. */ state.chunk_size = 32; break; } num_tasks = min_ii(num_tasks, (stop - start) / state.chunk_size); + /* TODO(sergey): If number of tasks happened to be 1, use single threaded + * path. + */ + /* NOTE: This way we are adding a memory barrier and ensure all worker * threads can read and modify the value, without any locks. */ atomic_fetch_and_add_int32(&state.iter, 0); |