From 07ec0effb61e18a3d2f1bad97ebf7f6cb5bb6b87 Mon Sep 17 00:00:00 2001 From: Brecht Van Lommel Date: Thu, 21 Sep 2017 03:37:22 +0200 Subject: Code cleanup: simplify kernel side work stealing code. --- intern/cycles/kernel/kernel_work_stealing.h | 112 ++++++++++------------------ 1 file changed, 38 insertions(+), 74 deletions(-) (limited to 'intern/cycles/kernel/kernel_work_stealing.h') diff --git a/intern/cycles/kernel/kernel_work_stealing.h b/intern/cycles/kernel/kernel_work_stealing.h index 28fc5ce1c30..0c11158e8da 100644 --- a/intern/cycles/kernel/kernel_work_stealing.h +++ b/intern/cycles/kernel/kernel_work_stealing.h @@ -27,90 +27,54 @@ CCL_NAMESPACE_BEGIN # pragma OPENCL EXTENSION cl_khr_global_int32_base_atomics : enable #endif -ccl_device_inline uint kernel_total_work_size(KernelGlobals *kg) -{ - return kernel_split_params.w * kernel_split_params.h * kernel_split_params.num_samples; -} - -ccl_device_inline uint kernel_num_work_pools(KernelGlobals *kg) -{ - return ccl_global_size(0) * ccl_global_size(1) / WORK_POOL_SIZE; -} - -ccl_device_inline uint work_pool_from_ray_index(KernelGlobals *kg, uint ray_index) -{ - return ray_index / WORK_POOL_SIZE; -} - -ccl_device_inline uint work_pool_work_size(KernelGlobals *kg, uint work_pool) -{ - uint total_work_size = kernel_total_work_size(kg); - uint num_pools = kernel_num_work_pools(kg); - - if(work_pool >= num_pools || work_pool * WORK_POOL_SIZE >= total_work_size) { - return 0; - } - - uint work_size = (total_work_size / (num_pools * WORK_POOL_SIZE)) * WORK_POOL_SIZE; - - uint remainder = (total_work_size % (num_pools * WORK_POOL_SIZE)); - if(work_pool < remainder / WORK_POOL_SIZE) { - work_size += WORK_POOL_SIZE; - } - else if(work_pool == remainder / WORK_POOL_SIZE) { - work_size += remainder % WORK_POOL_SIZE; - } - - return work_size; -} - -ccl_device_inline uint get_global_work_index(KernelGlobals *kg, uint work_index, uint ray_index) -{ - uint num_pools = kernel_num_work_pools(kg); - uint pool = work_pool_from_ray_index(kg, ray_index); - - return (work_index / WORK_POOL_SIZE) * (num_pools * WORK_POOL_SIZE) - + (pool * WORK_POOL_SIZE) - + (work_index % WORK_POOL_SIZE); -} - /* Returns true if there is work */ -ccl_device bool get_next_work(KernelGlobals *kg, ccl_private uint *work_index, uint ray_index) +ccl_device bool get_next_work(KernelGlobals *kg, + uint thread_index, + ccl_private uint *global_work_index) { - uint work_pool = work_pool_from_ray_index(kg, ray_index); - uint pool_size = work_pool_work_size(kg, work_pool); + uint total_work_size = kernel_split_params.w + * kernel_split_params.h + * kernel_split_params.num_samples; - if(pool_size == 0) { + /* With a small amount of work there may be more threads than work due to + * rounding up of global size, stop such threads immediately. */ + if(thread_index >= total_work_size) { return false; } - *work_index = atomic_fetch_and_inc_uint32(&kernel_split_params.work_pools[work_pool]); - return (*work_index < pool_size); -} + /* Increase atomic work index counter in pool. */ + uint pool = thread_index / WORK_POOL_SIZE; + uint work_index = atomic_fetch_and_inc_uint32(&kernel_split_params.work_pools[pool]); -/* This function assumes that the passed `work` is valid. */ -/* Decode sample number w.r.t. assigned `work`. */ -ccl_device uint get_work_sample(KernelGlobals *kg, uint work_index, uint ray_index) -{ - return get_global_work_index(kg, work_index, ray_index) / (kernel_split_params.w * kernel_split_params.h); -} + /* Map per-pool work index to a global work index. */ + uint global_size = ccl_global_size(0) * ccl_global_size(1); + kernel_assert(global_size % WORK_POOL_SIZE == 0); + kernel_assert(thread_index < global_size); -/* Decode pixel and tile position w.r.t. assigned `work`. */ -ccl_device void get_work_pixel_tile_position(KernelGlobals *kg, - ccl_private uint *pixel_x, - ccl_private uint *pixel_y, - ccl_private uint *tile_x, - ccl_private uint *tile_y, - uint work_index, - uint ray_index) -{ - uint pixel_index = get_global_work_index(kg, work_index, ray_index) % (kernel_split_params.w*kernel_split_params.h); + *global_work_index = (work_index / WORK_POOL_SIZE) * global_size + + (pool * WORK_POOL_SIZE) + + (work_index % WORK_POOL_SIZE); - *tile_x = pixel_index % kernel_split_params.w; - *tile_y = pixel_index / kernel_split_params.w; + /* Test if all work for this pool is done. */ + return (*global_work_index < total_work_size); +} - *pixel_x = *tile_x + kernel_split_params.x; - *pixel_y = *tile_y + kernel_split_params.y; +/* Map global work index to pixel X/Y and sample. */ +ccl_device_inline void get_work_pixel(KernelGlobals *kg, + uint global_work_index, + ccl_private uint *x, + ccl_private uint *y, + ccl_private uint *sample) +{ + uint tile_pixels = kernel_split_params.w * kernel_split_params.h; + uint sample_offset = global_work_index / tile_pixels; + uint pixel_offset = global_work_index - sample_offset * tile_pixels; + uint y_offset = pixel_offset / kernel_split_params.w; + uint x_offset = pixel_offset - y_offset * kernel_split_params.w; + + *x = kernel_split_params.x + x_offset; + *y = kernel_split_params.y + y_offset; + *sample = kernel_split_params.start_sample + sample_offset; } CCL_NAMESPACE_END -- cgit v1.2.3