ColossalAI/extensions/csrc/kernel/cuda/utils/gpu_launch_config.h

79 lines
2.5 KiB
C++

#pragma once
#include <cuda.h>
#include <cuda_runtime.h>
#include "nvgpu_dev_info.h"
namespace colossalAI {
namespace cuda {
namespace utils {
struct GPULaunchConfig {
dim3 block{1, 1, 1};
dim3 grid{1, 1, 1};
};
static GPULaunchConfig GetGPULaunchConfig1D(const NVGPUDevInfo& dev_info,
int64_t numel, int64_t vec_size) {
const int64_t max_threads_per_block = dev_info.GetMaxThreadsPerBlock();
const int64_t max_blocks_per_grid = dev_info.GetMaxGridDims()[0];
const int64_t kMinimumSize = 64;
const int64_t kMaximumSize = 512;
int64_t active_threads = (numel + vec_size - 1) / vec_size;
int64_t sm_num = dev_info.GetMultiProcessorCount();
// Note(LiuYang): expected threads should be in [64, 128, 256, 512] generally
int64_t expected_threads_per_block = kMaximumSize;
auto RoundUpToPowerOfTwo = [](int64_t x) {
bool is_power_of_two = false;
int64_t ret = 1;
int64_t y = x;
while (y > 0) {
is_power_of_two = ((ret ^ x) == 0);
y = (x >> 1);
ret = (ret << 1);
if (y > 0) is_power_of_two = false;
}
if (is_power_of_two) return x;
return ret;
};
if ((active_threads / (sm_num << 1)) < max_threads_per_block) {
expected_threads_per_block =
RoundUpToPowerOfTwo(active_threads / (sm_num << 1));
} else if ((active_threads / (sm_num << 2)) < max_threads_per_block) {
expected_threads_per_block =
RoundUpToPowerOfTwo(active_threads / (sm_num << 2));
}
expected_threads_per_block =
std::max(expected_threads_per_block, kMinimumSize);
int64_t expect_block_per_grid =
((active_threads + expected_threads_per_block - 1) /
expected_threads_per_block);
if (expect_block_per_grid > max_blocks_per_grid) {
expect_block_per_grid = max_blocks_per_grid;
expected_threads_per_block =
(active_threads + expect_block_per_grid - 1) / expect_block_per_grid;
if (expected_threads_per_block > max_threads_per_block)
throw std::invalid_argument(
"Threads required for current input exceed for current GPU!");
expected_threads_per_block =
RoundUpToPowerOfTwo(expected_threads_per_block);
expect_block_per_grid = ((active_threads + expected_threads_per_block - 1) /
expected_threads_per_block);
}
GPULaunchConfig config;
config.block.x = expected_threads_per_block;
config.grid.x = expect_block_per_grid;
return config;
}
} // namespace utils
} // namespace cuda
} // namespace colossalAI