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zbian
2021-10-28 18:21:23 +02:00
parent 2ebaefc542
commit 404ecbdcc6
409 changed files with 35853 additions and 0 deletions

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// modified from https://github.com/NVIDIA/apex/blob/master/csrc/multi_tensor_adam.cu
#include <torch/extension.h>
void multi_tensor_scale_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
float scale);
void multi_tensor_sgd_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
float wd,
float momentum,
float dampening,
float lr,
bool nesterov,
bool first_run,
bool wd_after_momentum,
float scale);
void multi_tensor_adam_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
const float lr,
const float beta1,
const float beta2,
const float epsilon,
const int step,
const int mode,
const int bias_correction,
const float weight_decay);
void multi_tensor_lamb_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
const float lr,
const float beta1,
const float beta2,
const float epsilon,
const int step,
const int bias_correction,
const float weight_decay,
const int grad_averaging,
const int mode,
at::Tensor global_grad_norm,
const float max_grad_norm,
at::optional<bool> use_nvlamb_python);
std::tuple<at::Tensor, at::Tensor> multi_tensor_l2norm_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
at::optional<bool> per_tensor_python);
PYBIND11_MODULE(TORCH_EXTENSION_NAME, m)
{
m.def("multi_tensor_scale", &multi_tensor_scale_cuda,
"Fused overflow check + scale for a list of contiguous tensors");
m.def("multi_tensor_sgd", &multi_tensor_sgd_cuda,
"Fused SGD optimizer for list of contiguous tensors");
m.def("multi_tensor_adam", &multi_tensor_adam_cuda,
"Compute and apply gradient update to parameters for Adam optimizer");
m.def("multi_tensor_lamb", &multi_tensor_lamb_cuda,
"Computes and apply update for LAMB optimizer");
m.def("multi_tensor_l2norm", &multi_tensor_l2norm_cuda,
"Computes L2 norm for a list of contiguous tensors");
}

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csrc/compat.h Normal file
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// modified from https://github.com/NVIDIA/apex/blob/master/csrc/compat.h
#ifndef TORCH_CHECK
#define TORCH_CHECK AT_CHECK
#endif
#ifdef VERSION_GE_1_3
#define DATA_PTR data_ptr
#else
#define DATA_PTR data
#endif

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csrc/multi_tensor_adam.cu Normal file
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// modified from https://github.com/NVIDIA/apex/blob/master/csrc/multi_tensor_adam.cu
#include <ATen/ATen.h>
#include <ATen/AccumulateType.h>
#include <ATen/cuda/CUDAContext.h>
#include <ATen/cuda/Exceptions.h>
// Another possibility:
// #include <torch/all.h>
#include <assert.h>
#include "type_shim.h"
#include "multi_tensor_apply.cuh"
#define BLOCK_SIZE 512
#define ILP 4
typedef enum
{
ADAM_MODE_0 = 0, // L2 regularization mode
ADAM_MODE_1 = 1 // Decoupled weight decay mode(AdamW)
} adamMode_t;
using MATH_T = float;
template <typename T>
struct AdamFunctor
{
__device__ __forceinline__ void operator()(
int chunk_size,
volatile int *noop_gmem,
TensorListMetadata<4> &tl,
const float beta1,
const float beta2,
const float beta1_correction,
const float beta2_correction,
const float epsilon,
const float lr,
adamMode_t mode,
const float decay)
{
// I'd like this kernel to propagate infs/nans.
// if(*noop_gmem == 1)
// return;
int tensor_loc = tl.block_to_tensor[blockIdx.x];
// potentially use to pass in list of scalar
// int tensor_num = tl.start_tensor_this_launch + tensor_loc;
int chunk_idx = tl.block_to_chunk[blockIdx.x];
int n = tl.sizes[tensor_loc];
T *g = (T *)tl.addresses[0][tensor_loc];
g += chunk_idx * chunk_size;
T *p = (T *)tl.addresses[1][tensor_loc];
p += chunk_idx * chunk_size;
T *m = (T *)tl.addresses[2][tensor_loc];
m += chunk_idx * chunk_size;
T *v = (T *)tl.addresses[3][tensor_loc];
v += chunk_idx * chunk_size;
n -= chunk_idx * chunk_size;
// see note in multi_tensor_scale_kernel.cu
for (int i_start = 0;
i_start < n && i_start < chunk_size;
i_start += blockDim.x * ILP)
{
MATH_T r_g[ILP];
MATH_T r_p[ILP];
MATH_T r_m[ILP];
MATH_T r_v[ILP];
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
r_g[ii] = g[i];
r_p[ii] = p[i];
r_m[ii] = m[i];
r_v[ii] = v[i];
}
else
{
r_g[ii] = MATH_T(0);
r_p[ii] = MATH_T(0);
r_m[ii] = MATH_T(0);
r_v[ii] = MATH_T(0);
}
}
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
if (mode == ADAM_MODE_0)
{ // L2
r_g[ii] = r_g[ii] + (decay * r_p[ii]);
r_m[ii] = beta1 * r_m[ii] + (1 - beta1) * r_g[ii];
r_v[ii] = beta2 * r_v[ii] + (1 - beta2) * r_g[ii] * r_g[ii];
MATH_T next_m_unbiased = r_m[ii] / beta1_correction;
MATH_T next_v_unbiased = r_v[ii] / beta2_correction;
MATH_T denom = sqrtf(next_v_unbiased) + epsilon;
MATH_T update = next_m_unbiased / denom;
r_p[ii] = r_p[ii] - (lr * update);
}
else
{ // weight decay
r_m[ii] = beta1 * r_m[ii] + (1 - beta1) * r_g[ii];
r_v[ii] = beta2 * r_v[ii] + (1 - beta2) * r_g[ii] * r_g[ii];
MATH_T next_m_unbiased = r_m[ii] / beta1_correction;
MATH_T next_v_unbiased = r_v[ii] / beta2_correction;
MATH_T denom = sqrtf(next_v_unbiased) + epsilon;
MATH_T update = (next_m_unbiased / denom) + (decay * r_p[ii]);
r_p[ii] = r_p[ii] - (lr * update);
}
}
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
p[i] = r_p[ii];
m[i] = r_m[ii];
v[i] = r_v[ii];
}
}
}
}
};
void multi_tensor_adam_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
const float lr,
const float beta1,
const float beta2,
const float epsilon,
const int step,
const int mode,
const int bias_correction,
const float weight_decay)
{
using namespace at;
// Handle bias correction mode
float bias_correction1 = 1.0f, bias_correction2 = 1.0f;
if (bias_correction == 1)
{
bias_correction1 = 1 - std::pow(beta1, step);
bias_correction2 = 1 - std::pow(beta2, step);
}
// Assume single type across p,g,m1,m2 now
DISPATCH_DOUBLE_FLOAT_AND_HALF(
tensor_lists[0][0].scalar_type(), 0, "adam",
multi_tensor_apply<4>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
AdamFunctor<scalar_t_0>(),
beta1,
beta2,
bias_correction1,
bias_correction2,
epsilon,
lr,
(adamMode_t)mode,
weight_decay);)
AT_CUDA_CHECK(cudaGetLastError());
}

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csrc/multi_tensor_apply.cuh Normal file
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// modified from https://github.com/NVIDIA/apex/blob/master/csrc/multi_tensor_apply.cuh
#include <ATen/ATen.h>
#include <ATen/AccumulateType.h>
#include <ATen/cuda/CUDAContext.h>
#include <ATen/cuda/Exceptions.h>
#include <c10/cuda/CUDAGuard.h>
#include "compat.h"
#include <assert.h>
// #include <iostream>
// This header is the one-stop shop for all your multi-tensor apply needs.
// TODO: Kernel arg size limit may be <4KB for some other cards (ie Jetson)
constexpr int depth_to_max_tensors[5] = {110, 64, 48, 36, 30};
constexpr int depth_to_max_blocks[5] = {320, 320, 320, 320, 320};
template <int n>
struct TensorListMetadata
{
void *addresses[n][depth_to_max_tensors[n - 1]];
int sizes[depth_to_max_tensors[n - 1]];
unsigned char block_to_tensor[depth_to_max_blocks[n - 1]];
int block_to_chunk[depth_to_max_blocks[n - 1]]; // I fear this needs to be a full int.
int start_tensor_this_launch;
};
template <typename T, typename U, typename... ArgTypes>
__global__ void multi_tensor_apply_kernel(
int chunk_size,
volatile int *noop_flag,
T tl,
U callable,
ArgTypes... args)
{
// Hand the chunk information to the user-supplied functor to process however it likes.
callable(chunk_size, noop_flag, tl, args...);
}
template <int depth, typename T, typename... ArgTypes>
void multi_tensor_apply(
int block_size,
int chunk_size,
const at::Tensor &noop_flag,
const std::vector<std::vector<at::Tensor>> &tensor_lists,
T callable,
ArgTypes... args)
{
TORCH_CHECK(tensor_lists.size() == depth, "tensor_lists.size() != depth");
int len0 = tensor_lists[0].size();
TORCH_CHECK(len0 > 0, "tensor_lists[0].size() is not > 0");
auto ref_device = tensor_lists[0][0].device();
TORCH_CHECK(ref_device.type() == at::kCUDA, "expected input to be on cuda");
for (int l = 0; l < tensor_lists.size(); l++) // No range-based for because I need indices
{
TORCH_CHECK(tensor_lists[l].size() == len0, "Size mismatch among tensor lists");
for (int t = 0; t < tensor_lists[l].size(); t++)
{
// TODO: Print which tensor fails.
bool contiguous_memory = tensor_lists[l][t].is_contiguous();
#ifdef VERSION_GE_1_5
contiguous_memory = (contiguous_memory || tensor_lists[l][t].is_contiguous(at::MemoryFormat::ChannelsLast));
#endif
TORCH_CHECK(contiguous_memory, "A tensor was not contiguous.");
TORCH_CHECK(tensor_lists[l][t].device() == ref_device, "A tensor was not on the same device as the first tensor");
TORCH_CHECK(tensor_lists[l][t].numel() == tensor_lists[0][t].numel(), "Size mismatch");
}
}
int ntensors = tensor_lists[0].size();
TensorListMetadata<depth> tl;
const at::cuda::OptionalCUDAGuard device_guard(device_of(tensor_lists[0][0]));
auto stream = at::cuda::getCurrentCUDAStream();
tl.start_tensor_this_launch = 0;
int loc_block_info = 0;
int loc_tensor_info = 0;
for (int t = 0; t < ntensors; t++)
{
tl.sizes[loc_tensor_info] = tensor_lists[0][t].numel();
for (int d = 0; d < depth; d++)
tl.addresses[d][loc_tensor_info] = tensor_lists[d][t].data_ptr();
loc_tensor_info++;
int chunks_this_tensor = (tensor_lists[0][t].numel() + chunk_size - 1) / chunk_size;
for (int chunk = 0; chunk < chunks_this_tensor; chunk++)
{
// std::cout << chunks_this_tensor << std::endl;
tl.block_to_tensor[loc_block_info] = loc_tensor_info - 1;
tl.block_to_chunk[loc_block_info] = chunk;
loc_block_info++;
bool tensors_full = (loc_tensor_info == depth_to_max_tensors[depth - 1] &&
chunk == chunks_this_tensor - 1);
bool blocks_full = (loc_block_info == depth_to_max_blocks[depth - 1]);
bool last_chunk = (t == ntensors - 1 && chunk == chunks_this_tensor - 1);
if (tensors_full || blocks_full || last_chunk)
{
// using accscalar_t = acc_type<scalar_t, true>;
multi_tensor_apply_kernel<<<loc_block_info, block_size, 0, stream>>>(
chunk_size,
noop_flag.DATA_PTR<int>(),
tl,
callable,
args...);
AT_CUDA_CHECK(cudaGetLastError());
// Reset. The control flow possibilities here make my brain hurt.
loc_block_info = 0;
if (chunk == chunks_this_tensor - 1)
{
// std::cout << "Hit case 1 " << cond1 << " " << cond2 << " " << cond3 << std::endl;
loc_tensor_info = 0;
tl.start_tensor_this_launch = t + 1;
}
else
{
// std::cout << "Hit case 2 " << cond1 << " " << cond2 << " " << cond3 << std::endl;
tl.sizes[0] = tl.sizes[loc_tensor_info - 1];
for (int d = 0; d < depth; d++)
tl.addresses[d][0] = tl.addresses[d][loc_tensor_info - 1];
loc_tensor_info = 1;
tl.start_tensor_this_launch = t;
}
}
}
}
}

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// modified from https://github.com/NVIDIA/apex/blob/master/csrc/multi_tensor_l2norm_kernel.cu
#include <ATen/ATen.h>
#include <ATen/AccumulateType.h>
#include <ATen/cuda/CUDAContext.h>
#include <ATen/cuda/Exceptions.h>
#include <c10/cuda/CUDAGuard.h>
// Another possibility:
// #include <torch/all.h>
#include <assert.h>
#include "type_shim.h"
#include "multi_tensor_apply.cuh"
#define BLOCK_SIZE 512
#define ILP 4
template <typename T>
__device__ __forceinline__ bool is_aligned(T *p)
{
return ((uint64_t)p) % (ILP * sizeof(T)) == 0;
}
template <typename T>
__device__ __forceinline__ void load_store(T *dst, T *src, int dst_offset, int src_offset)
{
typedef typename std::aligned_storage<ILP * sizeof(T), ILP * alignof(T)>::type LT;
((LT *)dst)[dst_offset] = ((LT *)src)[src_offset];
}
template <typename x_t>
struct L2NormFunctor
{
__device__ __forceinline__ void operator()(
int chunk_size,
volatile int *noop_gmem,
TensorListMetadata<1> &tl,
float *output,
float *output_per_tensor,
bool per_tensor,
int max_chunks_per_tensor)
{
// I'd like this kernel to propagate infs/nans.
// if(*noop_gmem == 1)
// return;
int tensor_loc = tl.block_to_tensor[blockIdx.x];
int chunk_idx = tl.block_to_chunk[blockIdx.x];
int n = tl.sizes[tensor_loc];
x_t *x = (x_t *)tl.addresses[0][tensor_loc];
x += chunk_idx * chunk_size;
n -= chunk_idx * chunk_size;
__shared__ float s_vals[512];
float vals[ILP]; // = {0}; // this probably works too but I want to be sure...
x_t r_x[ILP];
for (int i = 0; i < ILP; i++)
{
vals[i] = 0.f;
r_x[i] = 0;
}
// to make things simple, we put aligned case in a different code path
if (n % ILP == 0 && chunk_size % ILP == 0 && is_aligned(x))
{
for (int i_start = threadIdx.x; i_start * ILP < n && i_start * ILP < chunk_size; i_start += blockDim.x)
{
// load
load_store(r_x, x, 0, i_start);
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
float next = static_cast<float>(r_x[ii]);
vals[ii] += next * next;
}
}
}
else
{
for (int i_start = 0; i_start < n && i_start < chunk_size; i_start += blockDim.x * ILP)
{
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
float next = static_cast<float>(x[i]);
vals[ii] += next * next;
}
}
}
}
float val = 0.f;
for (int i = 0; i < ILP; i++)
val += vals[i];
float final = reduce_block_into_lanes(s_vals, val);
if (threadIdx.x == 0)
{
if (!isfinite(final))
*noop_gmem = 1; // Blindly fire off a write. These will race but that's ok.
output[blockIdx.x] += final;
if (per_tensor)
output_per_tensor[(tl.start_tensor_this_launch + tensor_loc) * max_chunks_per_tensor + chunk_idx] = final;
}
}
};
// Probably better to template, but since we are not likely to support other norm
template <typename x_t>
struct MaxNormFunctor
{
__device__ __forceinline__ void operator()(
int chunk_size,
volatile int *noop_gmem,
TensorListMetadata<1> &tl,
float *output,
float *output_per_tensor,
bool per_tensor,
int max_chunks_per_tensor)
{
// I'd like this kernel to propagate infs/nans.
// if(*noop_gmem == 1)
// return;
int tensor_loc = tl.block_to_tensor[blockIdx.x];
int chunk_idx = tl.block_to_chunk[blockIdx.x];
int n = tl.sizes[tensor_loc];
x_t *x = (x_t *)tl.addresses[0][tensor_loc];
x += chunk_idx * chunk_size;
n -= chunk_idx * chunk_size;
__shared__ float s_vals[512];
float vals[ILP]; // = {0}; // this probably works too but I want to be sure...
x_t r_x[ILP];
for (int i = 0; i < ILP; i++)
{
vals[i] = 0.f;
r_x[i] = 0;
}
// to make things simple, we put aligned case in a different code path
if (n % ILP == 0 && chunk_size % ILP == 0 && is_aligned(x))
{
for (int i_start = threadIdx.x; i_start * ILP < n && i_start * ILP < chunk_size; i_start += blockDim.x)
{
// load
load_store(r_x, x, 0, i_start);
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
float next = static_cast<float>(r_x[ii]);
vals[ii] = fmaxf(fabsf(vals[ii]), fabsf(next));
}
}
}
else
{
for (int i_start = 0; i_start < n && i_start < chunk_size; i_start += blockDim.x * ILP)
{
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
float next = static_cast<float>(x[i]);
vals[ii] = fmaxf(fabsf(vals[ii]), fabsf(next));
}
}
}
}
float val = 0.f;
for (int i = 0; i < ILP; i++)
val = fmaxf(fabsf(val), fabsf(vals[i]));
float final = reduce_block_into_lanes_max_op(s_vals, val);
if (threadIdx.x == 0)
{
if (!isfinite(final))
*noop_gmem = 1; // Blindly fire off a write. These will race but that's ok.
output[blockIdx.x] = fmaxf(fabsf(output[blockIdx.x]), fabsf(final));
if (per_tensor)
output_per_tensor[(tl.start_tensor_this_launch + tensor_loc) * max_chunks_per_tensor + chunk_idx] = final;
}
}
};
__global__ void cleanup(
float *output,
float *output_per_tensor,
float *ret,
float *ret_per_tensor,
bool per_tensor,
int max_chunks_per_tensor)
{
__shared__ float vals[512];
if (blockIdx.x == 0)
{
float val = 0;
if (threadIdx.x < 320)
val = output[threadIdx.x];
float final = reduce_block_into_lanes(vals, val);
if (threadIdx.x == 0)
*ret = sqrt(final);
}
if (per_tensor)
{
float *output_this_tensor = output_per_tensor + blockIdx.x * max_chunks_per_tensor;
float val = 0;
for (int i = threadIdx.x; i < max_chunks_per_tensor; i += blockDim.x)
val += output_this_tensor[i];
float final = reduce_block_into_lanes(vals, val);
if (threadIdx.x == 0)
ret_per_tensor[blockIdx.x] = sqrt(final);
}
}
__global__ void cleanup_v2(
float *output,
float *output_per_tensor,
float *ret,
float *ret_per_tensor,
bool per_tensor,
int max_chunks_per_tensor,
int norm_type,
float alpha,
float beta)
{
__shared__ float vals[512];
if (blockIdx.x == 0)
{
float val = 0;
if (threadIdx.x < 320)
val = output[threadIdx.x];
if (norm_type == 0)
{
float final = reduce_block_into_lanes_max_op(vals, val);
if (threadIdx.x == 0)
*ret = alpha * (*ret) + beta * final;
}
else
{
float final = reduce_block_into_lanes(vals, val);
if (threadIdx.x == 0)
*ret = sqrt(alpha * (*ret) * (*ret) + beta * final);
}
}
if (per_tensor)
{
float *output_this_tensor = output_per_tensor + blockIdx.x * max_chunks_per_tensor;
if (norm_type == 0)
{
float val = 0;
for (int i = threadIdx.x; i < max_chunks_per_tensor; i += blockDim.x)
val = fmaxf(fabsf(val), fabsf(output_this_tensor[i]));
float final = reduce_block_into_lanes_max_op(vals, val);
if (threadIdx.x == 0)
ret_per_tensor[blockIdx.x] = alpha * ret_per_tensor[blockIdx.x] + beta * final;
}
else
{
float val = 0;
for (int i = threadIdx.x; i < max_chunks_per_tensor; i += blockDim.x)
val += output_this_tensor[i];
float final = reduce_block_into_lanes(vals, val);
if (threadIdx.x == 0)
ret_per_tensor[blockIdx.x] = sqrt(alpha * ret_per_tensor[blockIdx.x] * ret_per_tensor[blockIdx.x] + beta * final);
}
}
}
std::tuple<at::Tensor, at::Tensor> multi_tensor_l2norm_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
at::optional<bool> per_tensor_python)
{
bool per_tensor = per_tensor_python.has_value() ? per_tensor_python.value() : false;
auto float_options = tensor_lists[0][0].options().dtype(at::kFloat);
auto output = at::zeros({320}, float_options);
at::Tensor output_per_tensor;
at::Tensor ret_per_tensor;
int ntensors = tensor_lists[0].size();
int max_chunks_per_tensor = -1;
if (per_tensor)
{
for (int t = 0; t < ntensors; t++)
{
int max_chunks_this_tensor = (tensor_lists[0][t].numel() + chunk_size - 1) / chunk_size;
if (max_chunks_this_tensor > max_chunks_per_tensor)
max_chunks_per_tensor = max_chunks_this_tensor;
}
output_per_tensor = at::zeros({ntensors * max_chunks_per_tensor}, float_options);
ret_per_tensor = at::empty({ntensors}, float_options);
}
else
{
ret_per_tensor = at::empty({0}, float_options);
}
DISPATCH_FLOAT_AND_HALF(tensor_lists[0][0].scalar_type(), 0, "multi_tensor_l2norm_cuda",
multi_tensor_apply<1>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
L2NormFunctor<scalar_t_0>(),
output.DATA_PTR<float>(),
per_tensor ? output_per_tensor.DATA_PTR<float>() : nullptr,
per_tensor,
max_chunks_per_tensor);)
AT_CUDA_CHECK(cudaGetLastError());
// AT_CUDA_CHECK(cudaDeviceSynchronize());
// This involves one more small kernel launches, but will be negligible end to end.
// I could get rid of these by hacking the functor + multi tensor harness with persistence
// logic, but keeping it simple for now
auto ret = at::empty({1}, output.options());
const at::cuda::OptionalCUDAGuard device_guard(device_of(output));
auto stream = at::cuda::getCurrentCUDAStream();
cleanup<<<per_tensor ? ntensors : 1, 512, 0, stream>>>(
output.DATA_PTR<float>(),
per_tensor ? output_per_tensor.DATA_PTR<float>() : nullptr,
ret.DATA_PTR<float>(),
per_tensor ? ret_per_tensor.DATA_PTR<float>() : nullptr,
per_tensor,
max_chunks_per_tensor);
return std::tuple<at::Tensor, at::Tensor>(ret, ret_per_tensor);
}
// Compute and update grad norm
// Here use a per tensor norm, and blend new norm(n) and old norm(gn) by
// L-2: gn = sqrt(a * gn^2 + b * n^2)
// L-inf: gn = a * gn + b * n
void multi_tensor_norm_out_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
at::Tensor out,
const float alpha,
const float beta,
const int norm_type)
{
auto float_options = tensor_lists[0][0].options().dtype(at::kFloat);
TORCH_CHECK(tensor_lists[0][0].device() == noop_flag.device(), "noop flag should be on the same device as tensors");
// we don't need global thus uses empty here
auto output = at::empty({320}, float_options);
at::Tensor output_per_tensor;
at::Tensor ret_per_tensor;
int ntensors = tensor_lists[0].size();
int max_chunks_per_tensor = -1;
for (int t = 0; t < ntensors; t++)
{
int max_chunks_this_tensor = (tensor_lists[0][t].numel() + chunk_size - 1) / chunk_size;
if (max_chunks_this_tensor > max_chunks_per_tensor)
max_chunks_per_tensor = max_chunks_this_tensor;
}
// Although it is single write then read, still need to be zero
// Since tailing element also participate cleanup
output_per_tensor = at::zeros({ntensors * max_chunks_per_tensor}, float_options);
if (norm_type == 0)
{
DISPATCH_FLOAT_AND_HALF(
tensor_lists[0][0].scalar_type(), 0, "multi_tensor_maxnorm_cuda",
multi_tensor_apply<1>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
MaxNormFunctor<scalar_t_0>(),
output.DATA_PTR<float>(),
output_per_tensor.DATA_PTR<float>(),
true,
max_chunks_per_tensor);)
}
else
{
DISPATCH_FLOAT_AND_HALF(
tensor_lists[0][0].scalar_type(), 0, "multi_tensor_l2norm_cuda",
multi_tensor_apply<1>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
L2NormFunctor<scalar_t_0>(),
output.DATA_PTR<float>(),
output_per_tensor.DATA_PTR<float>(),
true,
max_chunks_per_tensor);)
}
AT_CUDA_CHECK(cudaGetLastError());
// AT_CUDA_CHECK(cudaDeviceSynchronize());
// This involves one more small kernel launches, but will be negligible end to end.
// I could get rid of these by hacking the functor + multi tensor harness with persistence
// logic, but keeping it simple for now
auto ret = at::empty({1}, output.options());
// Adding the following device guard since it happens sometimes that the
// tensors are on one device and the cuda stream is on another device which
// results in ILLEGAL MEM ACCESS error.
const at::cuda::OptionalCUDAGuard device_guard(device_of(output));
auto stream = at::cuda::getCurrentCUDAStream();
cleanup_v2<<<ntensors, 512, 0, stream>>>(
output.DATA_PTR<float>(),
output_per_tensor.DATA_PTR<float>(),
ret.DATA_PTR<float>(),
out.DATA_PTR<float>(),
true,
max_chunks_per_tensor,
norm_type,
alpha,
beta);
return;
}

427
csrc/multi_tensor_lamb.cu Normal file
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// modified from https://github.com/NVIDIA/apex/blob/master/csrc/multi_tensor_lamb.cu
#include <ATen/ATen.h>
#include <ATen/AccumulateType.h>
#include <ATen/cuda/CUDAContext.h>
#include <ATen/cuda/Exceptions.h>
// Another possibility:
// #include <torch/all.h>
#include <assert.h>
#include "type_shim.h"
#include "multi_tensor_apply.cuh"
#define BLOCK_SIZE 512
#define ILP 4
template <typename T>
__device__ __forceinline__ bool is_aligned(T *p)
{
return ((uint64_t)p) % (ILP * sizeof(T)) == 0;
}
template <typename T>
__device__ __forceinline__ void load_store(T *dst, T *src, int dst_offset, int src_offset)
{
typedef typename std::aligned_storage<ILP * sizeof(T), ILP * alignof(T)>::type LT;
((LT *)dst)[dst_offset] = ((LT *)src)[src_offset];
}
typedef enum
{
MOMENT_MODE_0 = 0, // L2 regularization mode
MOMENT_MODE_1 = 1 // Decoupled weight decay mode
} adamMode_t;
std::tuple<at::Tensor, at::Tensor> multi_tensor_l2norm_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
at::optional<bool> per_tensor_python);
using MATH_T = float;
template <typename T>
struct LAMBStage1Functor
{
__device__ __forceinline__ void operator()(
int chunk_size,
volatile int *noop_gmem,
TensorListMetadata<4> &tl,
const float beta1,
const float beta2,
const float beta3,
const float beta1_correction,
const float beta2_correction,
const float epsilon,
adamMode_t mode,
const float decay,
const float *global_grad_norm,
const float max_global_grad_norm)
{
// I'd like this kernel to propagate infs/nans.
// if(*noop_gmem == 1)
// return;
int tensor_loc = tl.block_to_tensor[blockIdx.x];
int chunk_idx = tl.block_to_chunk[blockIdx.x];
int n = tl.sizes[tensor_loc];
float clipped_global_grad_norm = (*global_grad_norm) > max_global_grad_norm ? (*global_grad_norm) / max_global_grad_norm : 1.0f;
T *g = (T *)tl.addresses[0][tensor_loc];
g += chunk_idx * chunk_size;
T *p = (T *)tl.addresses[1][tensor_loc];
p += chunk_idx * chunk_size;
T *m = (T *)tl.addresses[2][tensor_loc];
m += chunk_idx * chunk_size;
T *v = (T *)tl.addresses[3][tensor_loc];
v += chunk_idx * chunk_size;
n -= chunk_idx * chunk_size;
MATH_T r_g[ILP];
MATH_T r_p[ILP];
MATH_T r_m[ILP];
MATH_T r_v[ILP];
// to make things simple, we put aligned case in a different code path
if (n % ILP == 0 &&
chunk_size % ILP == 0 &&
is_aligned(g) &&
is_aligned(p) &&
is_aligned(m) &&
is_aligned(v))
{
T l_g[ILP];
T l_p[ILP];
T l_m[ILP];
T l_v[ILP];
for (int i_start = threadIdx.x; i_start * ILP < n && i_start * ILP < chunk_size; i_start += blockDim.x)
{
// load
load_store(l_g, g, 0, i_start);
if (decay != 0)
load_store(l_p, p, 0, i_start);
load_store(l_m, m, 0, i_start);
load_store(l_v, v, 0, i_start);
// unpack
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
r_g[ii] = l_g[ii];
if (decay == 0)
{
r_p[ii] = MATH_T(0);
}
else
{
r_p[ii] = l_p[ii];
}
r_m[ii] = l_m[ii];
r_v[ii] = l_v[ii];
}
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
if (mode == MOMENT_MODE_0)
{
MATH_T scaled_grad = r_g[ii] / clipped_global_grad_norm;
// L2 on scaled grad
scaled_grad = scaled_grad + decay * r_p[ii];
r_m[ii] = r_m[ii] * beta1 + beta3 * scaled_grad;
r_v[ii] = r_v[ii] * beta2 + (1 - beta2) * scaled_grad * scaled_grad;
MATH_T next_m_unbiased = r_m[ii] / beta1_correction;
MATH_T next_v_unbiased = r_v[ii] / beta2_correction;
MATH_T denom = sqrtf(next_v_unbiased) + epsilon;
r_p[ii] = next_m_unbiased / denom;
}
else
{
MATH_T scaled_grad = r_g[ii] / clipped_global_grad_norm;
r_m[ii] = r_m[ii] * beta1 + beta3 * scaled_grad;
r_v[ii] = r_v[ii] * beta2 + (1 - beta2) * scaled_grad * scaled_grad;
MATH_T next_m_unbiased = r_m[ii] / beta1_correction;
MATH_T next_v_unbiased = r_v[ii] / beta2_correction;
MATH_T denom = sqrtf(next_v_unbiased) + epsilon;
r_p[ii] = (next_m_unbiased / denom) + (decay * r_p[ii]);
}
}
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
l_p[ii] = r_p[ii];
l_m[ii] = r_m[ii];
l_v[ii] = r_v[ii];
}
// store
load_store(g, l_p, i_start, 0);
load_store(m, l_m, i_start, 0);
load_store(v, l_v, i_start, 0);
}
}
else
{
// see note in multi_tensor_scale_kernel.cu
for (int i_start = 0;
i_start < n && i_start < chunk_size;
i_start += blockDim.x * ILP)
{
MATH_T r_g[ILP];
MATH_T r_p[ILP];
MATH_T r_m[ILP];
MATH_T r_v[ILP];
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
r_g[ii] = g[i];
// special ?optimization? for lamb stage 1
if (decay == 0)
{
r_p[ii] = MATH_T(0);
}
else
{
r_p[ii] = p[i];
}
r_m[ii] = m[i];
r_v[ii] = v[i];
}
else
{
r_g[ii] = MATH_T(0);
r_p[ii] = MATH_T(0);
r_m[ii] = MATH_T(0);
r_v[ii] = MATH_T(0);
}
}
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
if (mode == MOMENT_MODE_0)
{
MATH_T scaled_grad = r_g[ii] / clipped_global_grad_norm;
// L2 on scaled grad
scaled_grad = scaled_grad + decay * r_p[ii];
r_m[ii] = r_m[ii] * beta1 + beta3 * scaled_grad;
r_v[ii] = r_v[ii] * beta2 + (1 - beta2) * scaled_grad * scaled_grad;
MATH_T next_m_unbiased = r_m[ii] / beta1_correction;
MATH_T next_v_unbiased = r_v[ii] / beta2_correction;
MATH_T denom = sqrtf(next_v_unbiased) + epsilon;
r_p[ii] = next_m_unbiased / denom;
}
else
{
MATH_T scaled_grad = r_g[ii] / clipped_global_grad_norm;
r_m[ii] = r_m[ii] * beta1 + beta3 * scaled_grad;
r_v[ii] = r_v[ii] * beta2 + (1 - beta2) * scaled_grad * scaled_grad;
MATH_T next_m_unbiased = r_m[ii] / beta1_correction;
MATH_T next_v_unbiased = r_v[ii] / beta2_correction;
MATH_T denom = sqrtf(next_v_unbiased) + epsilon;
r_p[ii] = (next_m_unbiased / denom) + (decay * r_p[ii]);
}
}
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
g[i] = r_p[ii];
m[i] = r_m[ii];
v[i] = r_v[ii];
}
}
}
}
}
};
// Step 2 reads in 'update' value and per-tensor param_norm and update_norm.
// It computes new parameter value.
template <typename T>
struct LAMBStage2Functor
{
__device__ __forceinline__ void operator()(
int chunk_size,
volatile int *noop_gmem,
TensorListMetadata<2> &tl,
const float *per_tensor_param_norm,
const float *per_tensor_update_norm,
const float learning_rate,
const float decay,
bool use_nvlamb)
{
// I'd like this kernel to propagate infs/nans.
// if(*noop_gmem == 1)
// return;
int tensor_loc = tl.block_to_tensor[blockIdx.x];
int tensor_num = tl.start_tensor_this_launch + tensor_loc;
int chunk_idx = tl.block_to_chunk[blockIdx.x];
int n = tl.sizes[tensor_loc];
MATH_T ratio = learning_rate;
// nvlamb: apply adaptive learning rate to all parameters
// otherwise, only apply to those with non-zero weight decay
if (use_nvlamb || (decay != 0.0))
{
float param_norm = per_tensor_param_norm[tensor_num];
float update_norm = per_tensor_update_norm[tensor_num];
ratio = (update_norm != 0.0f && param_norm != 0.0f) ? learning_rate * (param_norm / update_norm) : learning_rate;
}
T *update = (T *)tl.addresses[0][tensor_loc];
update += chunk_idx * chunk_size;
T *p = (T *)tl.addresses[1][tensor_loc];
p += chunk_idx * chunk_size;
n -= chunk_idx * chunk_size;
// to make things simple, we put aligned case in a different code path
if (n % ILP == 0 &&
chunk_size % ILP == 0 &&
is_aligned(p) &&
is_aligned(update))
{
T r_p[ILP];
T r_update[ILP];
for (int i_start = threadIdx.x; i_start * ILP < n && i_start * ILP < chunk_size; i_start += blockDim.x)
{
// load
load_store(r_p, p, 0, i_start);
load_store(r_update, update, 0, i_start);
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
r_p[ii] = static_cast<MATH_T>(r_p[ii]) - (ratio * static_cast<MATH_T>(r_update[ii]));
}
load_store(p, r_p, i_start, 0);
}
}
else
{
for (int i_start = 0;
i_start < n && i_start < chunk_size;
i_start += blockDim.x * ILP)
{
MATH_T r_p[ILP];
MATH_T r_update[ILP];
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
r_p[ii] = p[i];
r_update[ii] = update[i];
}
}
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
r_p[ii] = r_p[ii] - (ratio * r_update[ii]);
}
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
p[i] = r_p[ii];
}
}
}
}
}
};
void multi_tensor_lamb_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
const float lr,
const float beta1,
const float beta2,
const float epsilon,
const int step,
const int bias_correction,
const float weight_decay,
const int grad_averaging,
const int mode,
at::Tensor global_grad_norm,
const float max_grad_norm,
at::optional<bool> use_nvlamb_python)
{
using namespace at;
// Master weight and 32bit momentum(potentially changing) is not handled by this
// So we assume every tensor are all in the same type
bool use_nvlamb = use_nvlamb_python.has_value() ? use_nvlamb_python.value() : false;
// Handle bias correction mode
float bias_correction1 = 1.0f, bias_correction2 = 1.0f;
if (bias_correction == 1)
{
bias_correction1 = 1 - std::pow(beta1, step);
bias_correction2 = 1 - std::pow(beta2, step);
}
// Handle grad averaging mode
float beta3 = 1.0f;
if (grad_averaging == 1)
beta3 = 1 - beta1;
std::vector<std::vector<at::Tensor>> grad_list(tensor_lists.begin(), tensor_lists.begin() + 1);
std::vector<std::vector<at::Tensor>> param_list(tensor_lists.begin() + 1, tensor_lists.begin() + 2);
// Compute per tensor param norm
auto param_norm_tuple = multi_tensor_l2norm_cuda(chunk_size, noop_flag, param_list, true);
// We now in-place modify grad to store update before compute its norm
// Generally this is not a issue since people modify grad in step() method all the time
// We can also grab list of empty tensor to avoid this, but I'd like to save space/cpu code
DISPATCH_FLOAT_AND_HALF(tensor_lists[0][0].scalar_type(), 0, "lamb_stage_1",
multi_tensor_apply<4>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
LAMBStage1Functor<scalar_t_0>(),
beta1,
beta2,
beta3, // 1-beta1 or 1 depends on averaging mode
bias_correction1,
bias_correction2,
epsilon,
(adamMode_t)mode,
weight_decay,
global_grad_norm.DATA_PTR<float>(),
max_grad_norm);)
// Compute update norms
auto update_norm_tuple = multi_tensor_l2norm_cuda(chunk_size, noop_flag, grad_list, true);
std::vector<std::vector<at::Tensor>> grad_param_list(tensor_lists.begin(), tensor_lists.begin() + 2);
DISPATCH_FLOAT_AND_HALF(tensor_lists[0][0].scalar_type(), 0, "lamb_stage_2",
multi_tensor_apply<2>(
BLOCK_SIZE,
chunk_size,
noop_flag,
grad_param_list,
LAMBStage2Functor<scalar_t_0>(),
std::get<1>(param_norm_tuple).DATA_PTR<float>(),
std::get<1>(update_norm_tuple).DATA_PTR<float>(),
lr,
weight_decay,
use_nvlamb);)
AT_CUDA_CHECK(cudaGetLastError());
}

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#include <ATen/ATen.h>
#include <ATen/AccumulateType.h>
#include <ATen/cuda/CUDAContext.h>
#include <ATen/cuda/Exceptions.h>
// Another possibility:
// #include <torch/all.h>
#include <assert.h>
// Stringstream is a big hammer, but I want to rely on operator<< for dtype.
#include <sstream>
#include "type_shim.h"
#include "multi_tensor_apply.cuh"
#define BLOCK_SIZE 512
#define ILP 4
template<typename T>
__device__ __forceinline__ bool is_aligned(T* p){
return ((uint64_t)p) % (ILP*sizeof(T)) == 0;
}
template<typename T>
__device__ __forceinline__ void load_store(T* dst, T* src, int dst_offset, int src_offset){
typedef typename std::aligned_storage<ILP*sizeof(T), ILP*alignof(T)>::type LT;
((LT*)dst)[dst_offset] = ((LT*)src)[src_offset];
}
template<typename in_t, typename out_t>
struct ScaleFunctor
{
__device__ __forceinline__ void operator()(
int chunk_size,
volatile int* noop_gmem,
TensorListMetadata<2>& tl,
float scale)
{
// I'd like this kernel to propagate infs/nans.
// if(*noop_gmem == 1)
// return;
int tensor_loc = tl.block_to_tensor[blockIdx.x];
int chunk_idx = tl.block_to_chunk[blockIdx.x];
int n = tl.sizes[tensor_loc];
in_t* in = (in_t*)tl.addresses[0][tensor_loc];
in += chunk_idx*chunk_size;
out_t* out = (out_t*)tl.addresses[1][tensor_loc];
out += chunk_idx*chunk_size;
n -= chunk_idx*chunk_size;
bool finite = true;
in_t r_in[ILP];
out_t r_out[ILP];
// to make things simple, we put aligned case in a different code path
if(n % ILP == 0 && chunk_size % ILP == 0 && is_aligned(in) && is_aligned(out))
{
for(int i_start = threadIdx.x; i_start*ILP < n && i_start*ILP < chunk_size; i_start += blockDim.x)
{
// load
load_store(r_in, in, 0 , i_start);
#pragma unroll
for(int ii = 0; ii < ILP; ii++)
{
r_out[ii] = static_cast<float>(r_in[ii]) * scale;
finite = finite && isfinite(r_in[ii]);
}
// store
load_store(out, r_out, i_start, 0);
}
}
else
{
// Non-divergent exit condition for __syncthreads, not necessary here
for(int i_start = 0; i_start < n && i_start < chunk_size; i_start += blockDim.x*ILP)
{
#pragma unroll
for(int ii = 0; ii < ILP; ii++)
{
r_in[ii] = 0;
int i = i_start + threadIdx.x + ii*blockDim.x;
if(i < n && i < chunk_size)
r_in[ii] = in[i];
}
// note for clarification to future michael:
// From a pure memory dependency perspective, there's likely no point unrolling
// the write loop, since writes just fire off once their LDGs arrive.
// Put another way, the STGs are dependent on the LDGs, but not on each other.
// There is still compute ILP benefit from unrolling the loop though.
#pragma unroll
for(int ii = 0; ii < ILP; ii++)
{
r_out[ii] = static_cast<float>(r_in[ii]) * scale;
finite = finite && isfinite(r_in[ii]);
}
#pragma unroll
for(int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii*blockDim.x;
if(i < n && i < chunk_size)
out[i] = r_out[ii];
}
}
}
if(!finite)
*noop_gmem = 1; // Blindly fire off a write. These will race but that's ok.
}
};
void multi_tensor_scale_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
float scale)
{
using namespace at;
// The output (downscaled) type is always float.
// If build times suffer, think about where to put this dispatch,
// and what logic should be moved out of multi_tensor_apply.
DISPATCH_FLOAT_AND_HALF(tensor_lists[0][0].scalar_type(), 0, "multi_tensor_scale_cuda",
DISPATCH_FLOAT_AND_HALF(tensor_lists[1][0].scalar_type(), 1, "multi_tensor_scale_cuda",
multi_tensor_apply<2>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
ScaleFunctor<scalar_t_0, scalar_t_1>(),
scale); ))
AT_CUDA_CHECK(cudaGetLastError());
// AT_CUDA_CHECK(cudaDeviceSynchronize());
}

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@@ -0,0 +1,282 @@
// modified from https://github.com/NVIDIA/apex/blob/master/csrc/multi_tensor_sgd_kernel.cu
#include <ATen/ATen.h>
#include <ATen/AccumulateType.h>
#include <ATen/cuda/CUDAContext.h>
#include <ATen/cuda/Exceptions.h>
#include "multi_tensor_apply.cuh"
#include "compat.h"
#include <assert.h>
#include <cuda_runtime.h>
#define BLOCK_SIZE 512
#define ILP 4
/**
* Perform fused SGD on multiple buffers
* N: number of tensors
* tl[0] : gradients
* tl[1] : weights
* tl[2] : momentum buffers
* tl[3] : fp16 weights (if appropriate)
* wd : weight_decay (scalar)
* momentum : momentum (scalar)
* dampening : momentum dampening (scalar)
* lr : learning rate (scalar)
* nesterov : enable nesterov (bool)
* first run : necessary for proper momentum handling & init
* wd_after_momentum : apply weight decay _after_ momentum instead of before
**/
template <int N, typename T_grad, typename T_weight>
struct SGDFunctor
{
__device__ __forceinline__ void operator()(
int chunk_size,
volatile int *noop_gmem,
TensorListMetadata<N> &tl,
float wd,
float momentum,
float dampening,
float lr,
bool nesterov,
bool first_run,
bool wd_after_momentum,
float scale)
{
// Early exit if we don't need to do anything
if (*noop_gmem)
return;
int tensor_loc = tl.block_to_tensor[blockIdx.x];
int chunk_idx = tl.block_to_chunk[blockIdx.x];
int n = tl.sizes[tensor_loc];
T_grad *grad_in = (T_grad *)tl.addresses[0][tensor_loc];
grad_in += chunk_idx * chunk_size;
T_weight *weight_in = (T_weight *)tl.addresses[1][tensor_loc];
weight_in += chunk_idx * chunk_size;
T_weight *mom_in = (T_weight *)tl.addresses[2][tensor_loc];
mom_in += chunk_idx * chunk_size;
at::Half *model_weights_out = nullptr;
if (N == 4)
{
model_weights_out = (at::Half *)tl.addresses[3][tensor_loc];
model_weights_out += chunk_idx * chunk_size;
}
n -= chunk_idx * chunk_size;
// Non-divergent exit condition for the __syncthreads
float incoming_grads[ILP];
float incoming_weights[ILP];
float incoming_moms[ILP];
for (int i_start = 0;
i_start < n && i_start < chunk_size;
i_start += blockDim.x * ILP)
{
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
incoming_grads[ii] = 0;
incoming_weights[ii] = 0;
incoming_moms[ii] = 0;
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
incoming_grads[ii] = static_cast<float>(grad_in[i]) * scale;
incoming_weights[ii] = static_cast<float>(weight_in[i]);
incoming_moms[ii] = static_cast<float>(mom_in[i]);
}
}
// note for clarification to future michael:
// From a pure memory dependency perspective, there's likely no point unrolling
// the write loop, since writes just fire off once their LDGs arrive.
// Put another way, the STGs are dependent on the LDGs, but not on each other.
// There is still compute ILP benefit from unrolling the loop though.
#pragma unroll
for (int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii * blockDim.x;
if (i < n && i < chunk_size)
{
// apply weight decay before momentum if necessary
if (wd != 0.f && !wd_after_momentum)
incoming_grads[ii] += wd * incoming_weights[ii];
if (momentum != 0.f)
{
if (!first_run)
incoming_moms[ii] = incoming_moms[ii] * momentum + (1.f - dampening) * incoming_grads[ii];
else // initialize momentums to current incoming grads
incoming_moms[ii] = incoming_grads[ii];
if (nesterov)
incoming_grads[ii] += momentum * incoming_moms[ii];
else
incoming_grads[ii] = incoming_moms[ii];
}
// Apply WD after momentum if desired
if (wd != 0.f && wd_after_momentum)
incoming_grads[ii] += wd * incoming_weights[ii];
// adjust the weight and write out
weight_in[i] += (-lr * incoming_grads[ii]);
// if necessary, write out an fp16 copy of the weights
if (N == 4)
model_weights_out[i] = static_cast<at::Half>(weight_in[i]);
// also write out the new momentum
if (momentum != 0.f)
mom_in[i] = incoming_moms[ii];
}
}
}
}
};
void multi_tensor_sgd_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
float wd,
float momentum,
float dampening,
float lr,
bool nesterov,
bool first_run,
bool wd_after_momentum,
float scale)
{
auto num_tensors = tensor_lists.size();
auto grad_type = tensor_lists[0][0].scalar_type();
auto weight_type = tensor_lists[1][0].scalar_type();
if (num_tensors == 4)
for (int i = 0; i < tensor_lists[3].size(); i++)
TORCH_CHECK(tensor_lists[3][i].scalar_type() == at::ScalarType::Half,
"Additional output tensors should always be fp16.");
TORCH_CHECK(noop_flag.device() == tensor_lists[0][0].device(), "expected noop flag to be on the same device as tensors");
// We have 3 possibilities to handle here, in terms of
// grad_type, param_type, momentum_type, requires_fp16_copy
// 1. fp16, fp16, fp16, No
// 2. fp32, fp32, fp32, No
// 3. fp16, fp32, fp32, Yes
// 4. fp32, fp32, fp32, Yes // this is the materialize_master_grads=True case
// It's easier to hardcode these possibilities than to use
// switches etc. to handle the cross-product of cases where
// we don't want the majority of them.
// Case 1. fp16, fp16, fp16, No
if (grad_type == at::ScalarType::Half &&
weight_type == at::ScalarType::Half &&
num_tensors == 3)
{
multi_tensor_apply<3>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
SGDFunctor<3, at::Half, at::Half>(),
wd,
momentum,
dampening,
lr,
nesterov,
first_run,
wd_after_momentum,
scale);
}
// Case 2. fp16, fp32, fp32, No
// else if (grad_type == at::ScalarType::Half &&
// weight_type == at::ScalarType::Float &&
// num_tensors == 3) {
// multi_tensor_apply<3>(
// BLOCK_SIZE,
// chunk_size,
// noop_flag,
// tensor_lists,
// SGDFunctor<3, at::Half, float>(),
// wd,
// momentum,
// dampening,
// lr,
// nesterov,
// first_run,
// wd_after_momentum);
// }
// Case 2. fp32, fp32, fp32, No
else if (grad_type == at::ScalarType::Float &&
weight_type == at::ScalarType::Float &&
num_tensors == 3)
{
multi_tensor_apply<3>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
SGDFunctor<3, float, float>(),
wd,
momentum,
dampening,
lr,
nesterov,
first_run,
wd_after_momentum,
scale);
}
// Case 3. fp16, fp32, fp32, Yes
else if (grad_type == at::ScalarType::Half &&
weight_type == at::ScalarType::Float &&
num_tensors == 4)
{
multi_tensor_apply<4>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
SGDFunctor<4, at::Half, float>(),
wd,
momentum,
dampening,
lr,
nesterov,
first_run,
wd_after_momentum,
scale);
}
// Case 4. fp32, fp32, fp32, Yes
else if (grad_type == at::ScalarType::Float &&
weight_type == at::ScalarType::Float &&
num_tensors == 4)
{
multi_tensor_apply<4>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
SGDFunctor<4, float, float>(),
wd,
momentum,
dampening,
lr,
nesterov,
first_run,
wd_after_momentum,
scale);
}
else
{
AT_ERROR("multi_tensor_sgd only supports some combinations of gradient & weight types. Given: ",
"gradient: ", grad_type, ", weight: ", weight_type, ", num_lists: ", num_tensors);
}
AT_CUDA_CHECK(cudaGetLastError());
}

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csrc/type_shim.h Normal file
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@@ -0,0 +1,202 @@
// modified from https://github.com/NVIDIA/apex/blob/master/csrc/type_shim.h
#include <ATen/ATen.h>
#include "compat.h"
// Forward/backward compatiblity hack around
// https://github.com/pytorch/pytorch/commit/3aeb78079bcd68282fe9117088e138b77318e288
// pending more future-proof guidance from upstream.
// struct TypeShim
// {
// const at::Type& payload;
// TypeShim(const at::Type& type) : payload(type) {}
// // Enable trivial conversion to a const at::Type& for pre-3aeb78
// operator const at::Type&(){ return payload; };
// // Enable dispatch switch statements to take *this directly for post-3aeb78
// //operator at::ScalarType(){ return payload.; };
// };
#define DISPATCH_FLOAT_AND_HALF(TYPE, LEVEL, NAME, ...) \
switch (TYPE) \
{ \
case at::ScalarType::Float: \
{ \
using scalar_t_##LEVEL = float; \
__VA_ARGS__; \
break; \
} \
case at::ScalarType::Half: \
{ \
using scalar_t_##LEVEL = at::Half; \
__VA_ARGS__; \
break; \
} \
default: \
AT_ERROR(#NAME, " not implemented for '", toString(TYPE), "'"); \
}
#define DISPATCH_FLOAT_HALF_AND_BYTE(TYPE, LEVEL, NAME, ...) \
switch (TYPE) \
{ \
case at::ScalarType::Float: \
{ \
using scalar_t_##LEVEL = float; \
__VA_ARGS__; \
break; \
} \
case at::ScalarType::Half: \
{ \
using scalar_t_##LEVEL = at::Half; \
__VA_ARGS__; \
break; \
} \
case at::ScalarType::Byte: \
{ \
using scalar_t_##LEVEL = uint8_t; \
__VA_ARGS__; \
break; \
} \
default: \
AT_ERROR(#NAME, " not implemented for '", toString(TYPE), "'"); \
}
#define DISPATCH_DOUBLE_FLOAT_AND_HALF(TYPE, LEVEL, NAME, ...) \
switch (TYPE) \
{ \
case at::ScalarType::Double: \
{ \
using scalar_t_##LEVEL = double; \
__VA_ARGS__; \
break; \
} \
case at::ScalarType::Float: \
{ \
using scalar_t_##LEVEL = float; \
__VA_ARGS__; \
break; \
} \
case at::ScalarType::Half: \
{ \
using scalar_t_##LEVEL = at::Half; \
__VA_ARGS__; \
break; \
} \
default: \
AT_ERROR(#NAME, " not implemented for '", toString(TYPE), "'"); \
}
#define DISPATCH_DOUBLE_AND_FLOAT(TYPE, LEVEL, NAME, ...) \
switch (TYPE) \
{ \
case at::ScalarType::Double: \
{ \
using scalar_t_##LEVEL = double; \
__VA_ARGS__; \
break; \
} \
case at::ScalarType::Float: \
{ \
using scalar_t_##LEVEL = float; \
__VA_ARGS__; \
break; \
} \
default: \
AT_ERROR(#NAME, " not implemented for '", toString(TYPE), "'"); \
}
template <typename T>
__device__ __forceinline__ T reduce_block_into_lanes(T *x,
T val,
int lanes = 1,
bool share_result = false) // lanes is intended to be <= 32.
{
int tid = threadIdx.x + threadIdx.y * blockDim.x;
int blockSize = blockDim.x * blockDim.y; // blockSize is intended to be a multiple of 32.
if (blockSize >= 64)
{
x[tid] = val;
__syncthreads();
}
#pragma unroll
for (int i = (blockSize >> 1); i >= 64; i >>= 1)
{
if (tid < i)
x[tid] = x[tid] + x[tid + i];
__syncthreads();
}
T final;
if (tid < 32)
{
if (blockSize >= 64)
final = x[tid] + x[tid + 32];
else
final = val;
// __SYNCWARP();
#pragma unroll
for (int i = 16; i >= lanes; i >>= 1)
final = final + __shfl_down_sync(0xffffffff, final, i);
}
if (share_result)
{
if (tid < lanes)
x[tid] = final; // EpilogueOp
// Make sure the smem result is visible to all warps.
__syncthreads();
}
return final;
}
template <typename T>
__device__ __forceinline__ T reduce_block_into_lanes_max_op(T *x,
T val,
int lanes = 1,
bool share_result = false) // lanes is intended to be <= 32.
{
int tid = threadIdx.x + threadIdx.y * blockDim.x;
int blockSize = blockDim.x * blockDim.y; // blockSize is intended to be a multiple of 32.
if (blockSize >= 64)
{
x[tid] = val;
__syncthreads();
}
#pragma unroll
for (int i = (blockSize >> 1); i >= 64; i >>= 1)
{
if (tid < i)
x[tid] = fmaxf(fabsf(x[tid]), fabsf(x[tid + i]));
__syncthreads();
}
T final;
if (tid < 32)
{
if (blockSize >= 64)
final = fmaxf(fabsf(x[tid]), fabsf(x[tid + 32]));
else
final = val;
// __SYNCWARP();
#pragma unroll
for (int i = 16; i >= lanes; i >>= 1)
final = fmaxf(fabsf(final), fabsf(__shfl_down_sync(0xffffffff, final, i)));
}
if (share_result)
{
if (tid < lanes)
x[tid] = final; // EpilogueOp
// Make sure the smem result is visible to all warps.
__syncthreads();
}
return final;
}