diff options
| -rw-r--r-- | source/blender/blenlib/BLI_task.h | 7 | ||||
| -rw-r--r-- | source/blender/blenlib/intern/task.c | 53 |
2 files changed, 46 insertions, 14 deletions
diff --git a/source/blender/blenlib/BLI_task.h b/source/blender/blenlib/BLI_task.h index d11ba15a7e0..85680d8aae8 100644 --- a/source/blender/blenlib/BLI_task.h +++ b/source/blender/blenlib/BLI_task.h @@ -216,11 +216,8 @@ BLI_INLINE void BLI_parallel_range_settings_defaults(ParallelRangeSettings *sett 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; + /* Use default heuristic to define actual chunk size. */ + settings->min_iter_per_thread = 0; } #ifdef __cplusplus diff --git a/source/blender/blenlib/intern/task.c b/source/blender/blenlib/intern/task.c index 85d39f2f98e..cc54fb6bd38 100644 --- a/source/blender/blenlib/intern/task.c +++ b/source/blender/blenlib/intern/task.c @@ -1054,6 +1054,49 @@ typedef struct ParallelRangeState { int chunk_size; } ParallelRangeState; +BLI_INLINE void task_parallel_range_calc_chunk_size(const ParallelRangeSettings *settings, + const int num_tasks, + ParallelRangeState *state) +{ + const int tot_items = state->stop - state->start; + int chunk_size = 0; + + if (settings->min_iter_per_thread > 0) { + /* Already set by user, no need to do anything here. */ + chunk_size = settings->min_iter_per_thread; + } + else { + /* Basic heuristic to avoid threading on low amount of items. We could make that limit + * configurable in settings too... */ + if (tot_items > 0 && tot_items < 256) { + chunk_size = tot_items; + } + /* NOTE: The idea here is to compensate for rather measurable threading + * overhead caused by fetching tasks. With too many CPU threads we are starting + * to spend too much time in those overheads. */ + else if (num_tasks > 32) { + chunk_size = 128; + } + else if (num_tasks > 16) { + chunk_size = 64; + } + else { + chunk_size = 32; + } + } + + BLI_assert(chunk_size > 0); + + switch (settings->scheduling_mode) { + case TASK_SCHEDULING_STATIC: + state->chunk_size = max_ii(chunk_size, tot_items / (num_tasks)); + break; + case TASK_SCHEDULING_DYNAMIC: + state->chunk_size = chunk_size; + break; + } +} + BLI_INLINE bool parallel_range_next_iter_get(ParallelRangeState *__restrict state, int *__restrict iter, int *__restrict count) @@ -1162,16 +1205,8 @@ void BLI_task_parallel_range(const int start, state.userdata = userdata; state.func = func; state.iter = start; - switch (settings->scheduling_mode) { - case TASK_SCHEDULING_STATIC: - 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; - } + task_parallel_range_calc_chunk_size(settings, num_tasks, &state); num_tasks = min_ii(num_tasks, max_ii(1, (stop - start) / state.chunk_size)); if (num_tasks == 1) { |