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Unverified Commit 093a27c5 authored by Daniël de Kok's avatar Daniël de Kok Committed by GitHub
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Add support for GPTQ Marlin (#2052) 

Add support for GPTQ Marlin kernels

GPTQ Marlin extends the Marlin kernels to support common GPTQ
configurations:

- bits: 4 or 8
- groupsize: -1, 32, 64, or 128
- desc_act: true/false

Using the GPTQ Marlin kernels requires repacking the parameters in the
Marlin quantizer format.

The kernels were contributed by Neural Magic to VLLM. We vendor them
here for convenience.
parent f433f1f7
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Showing with 4439 additions and 51 deletions
Dockerfile
View file @ 093a27c5
......@@ -140,9 +140,9 @@ RUN TORCH_CUDA_ARCH_LIST="8.0;8.6+PTX" make build-eetq
# Build marlin kernels
FROM kernel-builder as marlin-kernels-builder
WORKDIR /usr/src
COPY server/Makefile-marlin Makefile
COPY server/marlin/ .
# Build specific version of transformers
RUN TORCH_CUDA_ARCH_LIST="8.0;8.6+PTX" make build-marlin
RUN TORCH_CUDA_ARCH_LIST="8.0;8.6+PTX" python setup.py build
# Build Transformers CUDA kernels
FROM kernel-builder as custom-kernels-builder
......@@ -213,7 +213,7 @@ COPY --from=awq-kernels-builder /usr/src/llm-awq/awq/kernels/build/lib.linux-x86
# Copy build artifacts from eetq kernels builder
COPY --from=eetq-kernels-builder /usr/src/eetq/build/lib.linux-x86_64-cpython-310 /opt/conda/lib/python3.10/site-packages
# Copy build artifacts from marlin kernels builder
COPY --from=marlin-kernels-builder /usr/src/marlin/build/lib.linux-x86_64-cpython-310 /opt/conda/lib/python3.10/site-packages
COPY --from=marlin-kernels-builder /usr/src/build/lib.linux-x86_64-cpython-310 /opt/conda/lib/python3.10/site-packages
# Copy builds artifacts from vllm builder
COPY --from=vllm-builder /usr/src/vllm/build/lib.linux-x86_64-cpython-310 /opt/conda/lib/python3.10/site-packages
......
integration-tests/models/__snapshots__/test_flash_llama_gptq_marlin/test_flash_llama_gptq_marlin.json 0 → 100644
View file @ 093a27c5
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"text": "POST"
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"generated_text": "\n \"\"\"\n if request.method == 'POST"
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integration-tests/models/__snapshots__/test_flash_llama_gptq_marlin/test_flash_llama_gptq_marlin_all_params.json 0 → 100644
View file @ 093a27c5
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"generated_text": "Test request. The server has not yet sent any data.\n\n"
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integration-tests/models/__snapshots__/test_flash_llama_gptq_marlin/test_flash_llama_gptq_marlin_load.json 0 → 100644
View file @ 093a27c5
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{
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],
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},
"generated_text": "\n \"\"\"\n if request.method == 'POST"
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],
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{
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},
{
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{
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"special": false,
"text": " request"
},
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integration-tests/models/test_flash_llama_gptq_marlin.py 0 → 100644
View file @ 093a27c5
import pytest
@pytest.fixture(scope="module")
def flash_llama_gptq_marlin_handle(launcher):
with launcher(
"astronomer/Llama-3-8B-Instruct-GPTQ-4-Bit", num_shard=2, quantize="marlin"
) as handle:
yield handle
@pytest.fixture(scope="module")
async def flash_llama_gptq_marlin(flash_llama_gptq_marlin_handle):
await flash_llama_gptq_marlin_handle.health(300)
return flash_llama_gptq_marlin_handle.client
@pytest.mark.asyncio
@pytest.mark.private
async def test_flash_llama_gptq_marlin(flash_llama_gptq_marlin, response_snapshot):
response = await flash_llama_gptq_marlin.generate(
"Test request", max_new_tokens=10, decoder_input_details=True
)
assert response.details.generated_tokens == 10
assert response == response_snapshot
@pytest.mark.asyncio
@pytest.mark.private
async def test_flash_llama_gptq_marlin_all_params(
flash_llama_gptq_marlin, response_snapshot
):
response = await flash_llama_gptq_marlin.generate(
"Test request",
max_new_tokens=10,
repetition_penalty=1.2,
return_full_text=True,
temperature=0.5,
top_p=0.9,
top_k=10,
truncate=5,
typical_p=0.9,
watermark=True,
decoder_input_details=True,
seed=0,
)
assert response.details.generated_tokens == 10
assert response == response_snapshot
@pytest.mark.asyncio
@pytest.mark.private
async def test_flash_llama_gptq_marlin_load(
flash_llama_gptq_marlin, generate_load, response_snapshot
):
responses = await generate_load(
flash_llama_gptq_marlin, "Test request", max_new_tokens=10, n=4
)
assert len(responses) == 4
assert all([r.generated_text == responses[0].generated_text for r in responses])
assert responses == response_snapshot
server/Makefile
View file @ 093a27c5
......@@ -3,7 +3,6 @@ include Makefile-flash-att-v2
include Makefile-vllm
include Makefile-awq
include Makefile-eetq
include Makefile-marlin
include Makefile-selective-scan
unit-tests:
......
server/Makefile-marlin deleted 100644 → 0
View file @ f433f1f7
marlin_commit := 2f6d7c10e124b3c5fa29ff8d77d568bd7af3274c
build-marlin:
if [ ! -d 'marlin' ]; then \
pip install -U ninja packaging --no-cache-dir && \
git clone https://github.com/IST-DASLab/marlin.git marlin; \
fi
cd marlin && git fetch && git checkout $(marlin_commit) && python setup.py build
install-marlin: build-marlin
cd marlin && git fetch && git checkout $(marlin_commit) && pip install -e .
server/marlin/COPYRIGHT 0 → 100644
View file @ 093a27c5
These kernels were vendored from VLLM. The Marlin kernels were developed
by Elias Frantar and extended by Neural Magic.
---
Copyright (C) Marlin.2024 Elias Frantar
Modified by Neural Magic
Copyright 2024 The vLLM team.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
server/marlin/marlin_kernels/__init__.pyi 0 → 100644
View file @ 093a27c5
import torch
def gptq_marlin_gemm(
a: torch.Tensor,
b_q_weight: torch.Tensor,
b_scales: torch.Tensor,
g_idx: torch.Tensor,
perm: torch.Tensor,
workspace: torch.Tensor,
num_bits: int,
size_m: int,
size_n: int,
size_k: int,
is_k_full: bool,
) -> torch.Tensor:
"""
Matrix multiplication using Marlin kernels. This is an extension of
`marlin_gemm` that supports converted GPTQ kernels.
"""
...
def gptq_marlin_repack(
b_q_weight: torch.Tensor,
perm: torch.Tensor,
size_k: int,
size_n: int,
num_bits: int,
) -> torch.Tensor:
"""Repack GPTQ parameters for Marlin kernels."""
...
def marlin_gemm(
a: torch.Tensor,
b_q_weight: torch.Tensor,
b_scales: torch.Tensor,
workspace: torch.Tensor,
size_m: int,
size_n: int,
size_k: int,
) -> torch.Tensor:
"""
Matrix multiplication using Marlin kernels.
"""
...
server/marlin/marlin_kernels/ext.cpp 0 → 100644
View file @ 093a27c5
#include <torch/extension.h>
#include "ext.hh"
PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
m.def("gptq_marlin_gemm", &gptq_marlin_gemm,
"Marlin gemm with GPTQ compatibility");
m.def("gptq_marlin_repack", &gptq_marlin_repack,
"Repack GPTQ parameters for Marlin");
m.def("marlin_gemm", &marlin_gemm, "Marlin gemm");
}
server/marlin/marlin_kernels/ext.hh 0 → 100644
View file @ 093a27c5
#pragma once
#include <torch/library.h>
#if defined(__CUDA_ARCH__) && __CUDA_ARCH__ < 800
// No support for async
#else
torch::Tensor gptq_marlin_gemm(torch::Tensor &a, torch::Tensor &b_q_weight,
torch::Tensor &b_scales, torch::Tensor &g_idx,
torch::Tensor &perm, torch::Tensor &workspace,
int64_t num_bits, int64_t size_m, int64_t size_n,
int64_t size_k, bool is_k_full);
torch::Tensor gptq_marlin_repack(torch::Tensor &b_q_weight, torch::Tensor &perm,
int64_t size_k, int64_t size_n,
int64_t num_bits);
torch::Tensor marlin_gemm(torch::Tensor &a, torch::Tensor &b_q_weight,
torch::Tensor &b_scales, torch::Tensor &workspace,
int64_t size_m, int64_t size_n, int64_t size_k);
#endif
server/marlin/marlin_kernels/gptq_marlin.cu 0 → 100644
View file @ 093a27c5
/*
* Modified by Neural Magic
* Copyright (C) Marlin.2024 Elias Frantar
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Adapted from https://github.com/IST-DASLab/marlin
*/
#include "gptq_marlin.cuh"
#include "gptq_marlin_dtypes.cuh"
#define STATIC_ASSERT_SCALAR_TYPE_VALID(scalar_t) \
static_assert(std::is_same<scalar_t, half>::value || \
std::is_same<scalar_t, nv_bfloat16>::value, \
"only float16 and bfloat16 is supported");
template <typename T>
inline std::string str(T x) {
return std::to_string(x);
}
namespace gptq_marlin {
#if defined(__CUDA_ARCH__) && __CUDA_ARCH__ < 800
__global__ void permute_cols_kernel(int4 const* __restrict__ a_int4_ptr,
int const* __restrict__ perm_int_ptr,
int4* __restrict__ out_int4_ptr, int size_m,
int size_k, int block_rows) {}
template <typename scalar_t, // compute dtype, half or nv_float16
const int num_bits, // number of bits used for weights
const int threads, // number of threads in a threadblock
const int thread_m_blocks, // number of 16x16 blocks in the m
// dimension (batchsize) of the
// threadblock
const int thread_n_blocks, // same for n dimension (output)
const int thread_k_blocks, // same for k dimension (reduction)
const int stages, // number of stages for the async global->shared
// fetch pipeline
const bool has_act_order, // whether act_order is enabled
const int group_blocks = -1 // number of consecutive 16x16 blocks
// with a separate quantization scale
>
__global__ void Marlin(
const int4* __restrict__ A, // fp16 input matrix of shape mxk
const int4* __restrict__ B, // 4bit quantized weight matrix of shape kxn
int4* __restrict__ C, // fp16 output buffer of shape mxn
const int4* __restrict__ scales_ptr, // fp16 quantization scales of shape
// (k/groupsize)xn
const int* __restrict__ g_idx, // int32 group indices of shape k
int num_groups, // number of scale groups per output channel
int prob_m, // batch dimension m
int prob_n, // output dimension n
int prob_k, // reduction dimension k
int* locks // extra global storage for barrier synchronization
) {}
} // namespace gptq_marlin
torch::Tensor gptq_marlin_gemm(torch::Tensor& a, torch::Tensor& b_q_weight,
torch::Tensor& b_scales, torch::Tensor& g_idx,
torch::Tensor& perm, torch::Tensor& workspace,
int64_t num_bits, int64_t size_m, int64_t size_n,
int64_t size_k, bool is_k_full) {
TORCH_CHECK_NOT_IMPLEMENTED(false,
"marlin_gemm(..) requires CUDA_ARCH >= 8.0");
return torch::empty({1, 1});
}
#else
// m16n8k16 tensor core mma instruction with fp16 inputs and fp32
// output/accumulation.
template <typename scalar_t>
__device__ inline void mma(const typename ScalarType<scalar_t>::FragA& a_frag,
const typename ScalarType<scalar_t>::FragB& frag_b,
typename ScalarType<scalar_t>::FragC& frag_c) {
const uint32_t* a = reinterpret_cast<const uint32_t*>(&a_frag);
const uint32_t* b = reinterpret_cast<const uint32_t*>(&frag_b);
float* c = reinterpret_cast<float*>(&frag_c);
if constexpr (std::is_same<scalar_t, half>::value) {
asm volatile(
"mma.sync.aligned.m16n8k16.row.col.f32.f16.f16.f32 "
"{%0,%1,%2,%3}, {%4,%5,%6,%7}, {%8,%9}, {%10,%11,%12,%13};\n"
: "=f"(c[0]), "=f"(c[1]), "=f"(c[2]), "=f"(c[3])
: "r"(a[0]), "r"(a[1]), "r"(a[2]), "r"(a[3]), "r"(b[0]), "r"(b[1]),
"f"(c[0]), "f"(c[1]), "f"(c[2]), "f"(c[3]));
} else if constexpr (std::is_same<scalar_t, nv_bfloat16>::value) {
asm volatile(
"mma.sync.aligned.m16n8k16.row.col.f32.bf16.bf16.f32 "
"{%0,%1,%2,%3}, {%4,%5,%6,%7}, {%8,%9}, {%10,%11,%12,%13};\n"
: "=f"(c[0]), "=f"(c[1]), "=f"(c[2]), "=f"(c[3])
: "r"(a[0]), "r"(a[1]), "r"(a[2]), "r"(a[3]), "r"(b[0]), "r"(b[1]),
"f"(c[0]), "f"(c[1]), "f"(c[2]), "f"(c[3]));
} else {
STATIC_ASSERT_SCALAR_TYPE_VALID(scalar_t);
}
}
// Instruction for loading a full 16x16 matrix fragment of operand A from shared
// memory, directly in tensor core layout.
template <typename scalar_t>
__device__ inline void ldsm4(typename ScalarType<scalar_t>::FragA& frag_a,
const void* smem_ptr) {
uint32_t* a = reinterpret_cast<uint32_t*>(&frag_a);
uint32_t smem = static_cast<uint32_t>(__cvta_generic_to_shared(smem_ptr));
asm volatile("ldmatrix.sync.aligned.m8n8.x4.shared.b16 {%0,%1,%2,%3}, [%4];\n"
: "=r"(a[0]), "=r"(a[1]), "=r"(a[2]), "=r"(a[3])
: "r"(smem));
}
// Lookup-table based 3-input logical operation; explicitly used for
// dequantization as the compiler does not seem to automatically recognize it in
// all cases.
template <int lut>
__device__ inline int lop3(int a, int b, int c) {
int res;
asm volatile("lop3.b32 %0, %1, %2, %3, %4;\n"
: "=r"(res)
: "r"(a), "r"(b), "r"(c), "n"(lut));
return res;
}
// Constructs destination register by taking bytes from 2 sources (based on
// mask)
template <int start_byte, int mask>
__device__ inline uint32_t prmt(uint32_t a) {
uint32_t res;
asm volatile("prmt.b32 %0, %1, %2, %3;\n"
: "=r"(res)
: "r"(a), "n"(start_byte), "n"(mask));
return res;
}
// Efficiently dequantize an int32 value into a full B-fragment of 4 fp16
// values. We mostly follow the strategy in the link below, with some small
// changes:
// - FP16:
// https://github.com/NVIDIA/FasterTransformer/blob/release/v5.3_tag/src/fastertransformer/cutlass_extensions/include/cutlass_extensions/interleaved_numeric_conversion.h#L215-L287
// - BF16:
// https://github.com/NVIDIA/FasterTransformer/blob/release/v5.3_tag/src/fastertransformer/cutlass_extensions/include/cutlass_extensions/interleaved_numeric_conversion.h#L327-L385
template <typename scalar_t>
__device__ inline typename ScalarType<scalar_t>::FragB dequant_4bit(int q) {
STATIC_ASSERT_SCALAR_TYPE_VALID(scalar_t);
}
template <>
__device__ inline typename ScalarType<half>::FragB dequant_4bit<half>(int q) {
const int LO = 0x000f000f;
const int HI = 0x00f000f0;
const int EX = 0x64006400;
// Guarantee that the `(a & b) | c` operations are LOP3s.
int lo = lop3<(0xf0 & 0xcc) | 0xaa>(q, LO, EX);
int hi = lop3<(0xf0 & 0xcc) | 0xaa>(q, HI, EX);
// We want signed int4 outputs, hence we fuse the `-8` symmetric zero point
// directly into `SUB` and `ADD`.
const int SUB = 0x64086408;
const int MUL = 0x2c002c00;
const int ADD = 0xd480d480;
typename ScalarType<half>::FragB frag_b;
frag_b[0] = __hsub2(*reinterpret_cast<half2*>(&lo),
*reinterpret_cast<const half2*>(&SUB));
frag_b[1] = __hfma2(*reinterpret_cast<half2*>(&hi),
*reinterpret_cast<const half2*>(&MUL),
*reinterpret_cast<const half2*>(&ADD));
return frag_b;
}
template <>
__device__ inline typename ScalarType<nv_bfloat16>::FragB
dequant_4bit<nv_bfloat16>(int q) {
static constexpr uint32_t MASK = 0x000f000f;
static constexpr uint32_t EX = 0x43004300;
// Guarantee that the `(a & b) | c` operations are LOP3s.
int lo = lop3<(0xf0 & 0xcc) | 0xaa>(q, MASK, EX);
q >>= 4;
int hi = lop3<(0xf0 & 0xcc) | 0xaa>(q, MASK, EX);
typename ScalarType<nv_bfloat16>::FragB frag_b;
static constexpr uint32_t MUL = 0x3F803F80;
static constexpr uint32_t ADD = 0xC308C308;
frag_b[0] = __hfma2(*reinterpret_cast<nv_bfloat162*>(&lo),
*reinterpret_cast<const nv_bfloat162*>(&MUL),
*reinterpret_cast<const nv_bfloat162*>(&ADD));
frag_b[1] = __hfma2(*reinterpret_cast<nv_bfloat162*>(&hi),
*reinterpret_cast<const nv_bfloat162*>(&MUL),
*reinterpret_cast<const nv_bfloat162*>(&ADD));
return frag_b;
}
// Fast Int8ToFp16/Int8ToBf16: Efficiently dequantize 8bit int values to fp16 or
// bf16 Reference:
// - FP16:
// https://github.com/NVIDIA/FasterTransformer/blob/release/v5.3_tag/src/fastertransformer/cutlass_extensions/include/cutlass_extensions/interleaved_numeric_conversion.h#L53-L85
// - BF16:
// https://github.com/NVIDIA/FasterTransformer/blob/release/v5.3_tag/src/fastertransformer/cutlass_extensions/include/cutlass_extensions/interleaved_numeric_conversion.h#L125-L175
template <typename scalar_t>
__device__ inline typename ScalarType<scalar_t>::FragB dequant_8bit(int q) {
STATIC_ASSERT_SCALAR_TYPE_VALID(scalar_t);
}
template <>
__device__ inline typename ScalarType<half>::FragB dequant_8bit<half>(int q) {
static constexpr uint32_t mask_for_elt_01 = 0x5250;
static constexpr uint32_t mask_for_elt_23 = 0x5351;
static constexpr uint32_t start_byte_for_fp16 = 0x64646464;
uint32_t lo = prmt<start_byte_for_fp16, mask_for_elt_01>(q);
uint32_t hi = prmt<start_byte_for_fp16, mask_for_elt_23>(q);
static constexpr uint32_t I8s_TO_F16s_MAGIC_NUM = 0x64806480;
typename ScalarType<half>::FragB frag_b;
frag_b[0] = __hsub2(*reinterpret_cast<half2*>(&lo),
*reinterpret_cast<const half2*>(&I8s_TO_F16s_MAGIC_NUM));
frag_b[1] = __hsub2(*reinterpret_cast<half2*>(&hi),
*reinterpret_cast<const half2*>(&I8s_TO_F16s_MAGIC_NUM));
return frag_b;
}
template <>
__device__ inline typename ScalarType<nv_bfloat16>::FragB
dequant_8bit<nv_bfloat16>(int q) {
typename ScalarType<nv_bfloat16>::FragB frag_b;
float fp32_intermediates[4];
uint32_t* fp32_intermediates_casted =
reinterpret_cast<uint32_t*>(fp32_intermediates);
static constexpr uint32_t fp32_base = 0x4B000000;
fp32_intermediates_casted[0] = __byte_perm(q, fp32_base, 0x7650);
fp32_intermediates_casted[1] = __byte_perm(q, fp32_base, 0x7652);
fp32_intermediates_casted[2] = __byte_perm(q, fp32_base, 0x7651);
fp32_intermediates_casted[3] = __byte_perm(q, fp32_base, 0x7653);
fp32_intermediates[0] -= 8388736.f;
fp32_intermediates[1] -= 8388736.f;
fp32_intermediates[2] -= 8388736.f;
fp32_intermediates[3] -= 8388736.f;
uint32_t* bf16_result_ptr = reinterpret_cast<uint32_t*>(&frag_b);
bf16_result_ptr[0] = __byte_perm(fp32_intermediates_casted[0],
fp32_intermediates_casted[1], 0x7632);
bf16_result_ptr[1] = __byte_perm(fp32_intermediates_casted[2],
fp32_intermediates_casted[3], 0x7632);
return frag_b;
}
// Multiply dequantized values by the corresponding quantization scale; used
// only for grouped quantization.
template <typename scalar_t>
__device__ inline void scale(typename ScalarType<scalar_t>::FragB& frag_b,
typename ScalarType<scalar_t>::FragS& frag_s,
int i) {
using scalar_t2 = typename ScalarType<scalar_t>::scalar_t2;
scalar_t2 s =
ScalarType<scalar_t>::num2num2(reinterpret_cast<scalar_t*>(&frag_s)[i]);
frag_b[0] = __hmul2(frag_b[0], s);
frag_b[1] = __hmul2(frag_b[1], s);
}
// Same as above, but for act_order (each K is multiplied individually)
template <typename scalar_t>
__device__ inline void scale4(typename ScalarType<scalar_t>::FragB& frag_b,
typename ScalarType<scalar_t>::FragS& frag_s_1,
typename ScalarType<scalar_t>::FragS& frag_s_2,
typename ScalarType<scalar_t>::FragS& frag_s_3,
typename ScalarType<scalar_t>::FragS& frag_s_4,
int i) {
using scalar_t2 = typename ScalarType<scalar_t>::scalar_t2;
scalar_t2 s_val_1_2;
s_val_1_2.x = reinterpret_cast<scalar_t*>(&frag_s_1)[i];
s_val_1_2.y = reinterpret_cast<scalar_t*>(&frag_s_2)[i];
scalar_t2 s_val_3_4;
s_val_3_4.x = reinterpret_cast<scalar_t*>(&frag_s_3)[i];
s_val_3_4.y = reinterpret_cast<scalar_t*>(&frag_s_4)[i];
frag_b[0] = __hmul2(frag_b[0], s_val_1_2);
frag_b[1] = __hmul2(frag_b[1], s_val_3_4);
}
// Given 2 floats multiply by 2 scales (halves)
template <typename scalar_t>
__device__ inline void scale_float(float* c,
typename ScalarType<scalar_t>::FragS& s) {
scalar_t* s_ptr = reinterpret_cast<scalar_t*>(&s);
c[0] = __fmul_rn(c[0], ScalarType<scalar_t>::num2float(s_ptr[0]));
c[1] = __fmul_rn(c[1], ScalarType<scalar_t>::num2float(s_ptr[1]));
}
// Wait until barrier reaches `count`, then lock for current threadblock.
__device__ inline void barrier_acquire(int* lock, int count) {
if (threadIdx.x == 0) {
int state = -1;
do
// Guarantee that subsequent writes by this threadblock will be visible
// globally.
asm volatile("ld.global.acquire.gpu.b32 %0, [%1];\n"
: "=r"(state)
: "l"(lock));
while (state != count);
}
__syncthreads();
}
// Release barrier and increment visitation count.
__device__ inline void barrier_release(int* lock, bool reset = false) {
__syncthreads();
if (threadIdx.x == 0) {
if (reset) {
lock[0] = 0;
return;
}
int val = 1;
// Make sure that all writes since acquiring this barrier are visible
// globally, while releasing the barrier.
asm volatile("fence.acq_rel.gpu;\n");
asm volatile("red.relaxed.gpu.global.add.s32 [%0], %1;\n"
:
: "l"(lock), "r"(val));
}
}
// For a given "a" of size [M,K] performs a permutation of the K columns based
// on the given "perm" indices.
__global__ void permute_cols_kernel(int4 const* __restrict__ a_int4_ptr,
int const* __restrict__ perm_int_ptr,
int4* __restrict__ out_int4_ptr, int size_m,
int size_k, int block_rows) {
int start_row = block_rows * blockIdx.x;
int finish_row = start_row + block_rows;
if (finish_row > size_m) {
finish_row = size_m;
}
int cur_block_rows = finish_row - start_row;
int row_stride = size_k * sizeof(half) / 16;
auto permute_row = [&](int row) {
int iters = size_k / default_threads;
int rest = size_k % default_threads;
int offset = row * row_stride;
half const* a_row_half = reinterpret_cast<half const*>(a_int4_ptr + offset);
half* out_half = reinterpret_cast<half*>(out_int4_ptr + offset);
int base_k = 0;
for (int i = 0; i < iters; i++) {
int cur_k = base_k + threadIdx.x;
int src_pos = perm_int_ptr[cur_k];
out_half[cur_k] = a_row_half[src_pos];
base_k += default_threads;
}
if (rest) {
if (threadIdx.x < rest) {
int cur_k = base_k + threadIdx.x;
int src_pos = perm_int_ptr[cur_k];
out_half[cur_k] = a_row_half[src_pos];
}
}
};
for (int i = 0; i < cur_block_rows; i++) {
int cur_row = start_row + i;
if (cur_row < size_m) {
permute_row(cur_row);
}
}
}
template <typename scalar_t, // compute dtype, half or nv_float16
const int num_bits, // number of bits used for weights
const int threads, // number of threads in a threadblock
const int thread_m_blocks, // number of 16x16 blocks in the m
// dimension (batchsize) of the
// threadblock
const int thread_n_blocks, // same for n dimension (output)
const int thread_k_blocks, // same for k dimension (reduction)
const int stages, // number of stages for the async global->shared
// fetch pipeline
const bool has_act_order, // whether act_order is enabled
const int group_blocks = -1 // number of consecutive 16x16 blocks
// with a separate quantization scale
>
__global__ void Marlin(
const int4* __restrict__ A, // fp16 input matrix of shape mxk
const int4* __restrict__ B, // 4bit quantized weight matrix of shape kxn
int4* __restrict__ C, // fp16 output buffer of shape mxn
const int4* __restrict__ scales_ptr, // fp16 quantization scales of shape
// (k/groupsize)xn
const int* __restrict__ g_idx, // int32 group indices of shape k
int num_groups, // number of scale groups per output channel
int prob_m, // batch dimension m
int prob_n, // output dimension n
int prob_k, // reduction dimension k
int* locks // extra global storage for barrier synchronization
) {
// Each threadblock processes one "stripe" of the B matrix with (roughly) the
// same size, which might involve multiple column "slices" (of width 16 *
// `thread_n_blocks`). Stripes are defined as shown in the 3x3 matrix 5 SM
// example:
// 0 1 3
// 0 2 3
// 1 2 4
// While this kind of partitioning makes things somewhat more complicated, it
// ensures good utilization of all SMs for many kinds of shape and GPU
// configurations, while requiring as few slow global cross-threadblock
// reductions as possible.
using Dtype = ScalarType<scalar_t>;
using scalar_t2 = typename ScalarType<scalar_t>::scalar_t2;
using FragA = typename ScalarType<scalar_t>::FragA;
using FragB = typename ScalarType<scalar_t>::FragB;
using FragC = typename ScalarType<scalar_t>::FragC;
using FragS = typename ScalarType<scalar_t>::FragS;
constexpr int pack_factor = 32 / num_bits;
// For larger GEMMs we run multiple batchsize 64 versions in parallel for a
// better partitioning with less reductions
int parallel = 1;
if (prob_m > 16 * thread_m_blocks) {
parallel = prob_m / (16 * thread_m_blocks);
prob_m = 16 * thread_m_blocks;
}
int k_tiles = prob_k / 16 / thread_k_blocks;
int n_tiles = prob_n / 16 / thread_n_blocks;
int iters = div_ceil(k_tiles * n_tiles * parallel, gridDim.x);
if constexpr (!has_act_order && group_blocks != -1) {
if (group_blocks >= thread_k_blocks) {
// Ensure that the number of tiles in each stripe is a multiple of the
// groupsize; this avoids an annoying special case where a stripe starts
// in the middle of group.
iters = (group_blocks / thread_k_blocks) *
div_ceil(iters, (group_blocks / thread_k_blocks));
}
}
int slice_row = (iters * blockIdx.x) % k_tiles;
int slice_col_par = (iters * blockIdx.x) / k_tiles;
int slice_col = slice_col_par;
int slice_iters; // number of threadblock tiles in the current slice
int slice_count =
0; // total number of active threadblocks in the current slice
int slice_idx; // index of threadblock in current slice; numbered bottom to
// top
// We can easily implement parallel problem execution by just remapping
// indices and advancing global pointers
if (slice_col_par >= n_tiles) {
A += (slice_col_par / n_tiles) * 16 * thread_m_blocks * prob_k / 8;
C += (slice_col_par / n_tiles) * 16 * thread_m_blocks * prob_n / 8;
locks += (slice_col_par / n_tiles) * n_tiles;
slice_col = slice_col_par % n_tiles;
}
// Compute all information about the current slice which is required for
// synchronization.
auto init_slice = [&]() {
slice_iters =
iters * (blockIdx.x + 1) - (k_tiles * slice_col_par + slice_row);
if (slice_iters < 0 || slice_col_par >= n_tiles * parallel) slice_iters = 0;
if (slice_iters == 0) return;
if (slice_row + slice_iters > k_tiles) slice_iters = k_tiles - slice_row;
slice_count = 1;
slice_idx = 0;
int col_first = iters * div_ceil(k_tiles * slice_col_par, iters);
if (col_first <= k_tiles * (slice_col_par + 1)) {
int col_off = col_first - k_tiles * slice_col_par;
slice_count = div_ceil(k_tiles - col_off, iters);
if (col_off > 0) slice_count++;
int delta_first = iters * blockIdx.x - col_first;
if (delta_first < 0 || (col_off == 0 && delta_first == 0))
slice_idx = slice_count - 1;
else {
slice_idx = slice_count - 1 - delta_first / iters;
if (col_off > 0) slice_idx--;
}
}
if (slice_col == n_tiles) {
A += 16 * thread_m_blocks * prob_k / 8;
C += 16 * thread_m_blocks * prob_n / 8;
locks += n_tiles;
slice_col = 0;
}
};
init_slice();
// A sizes/strides
// stride of the A matrix in global memory
int a_gl_stride = prob_k / 8;
// stride of an A matrix tile in shared memory
constexpr int a_sh_stride = 16 * thread_k_blocks / 8;
// delta between subsequent A tiles in global memory
constexpr int a_gl_rd_delta_o = 16 * thread_k_blocks / 8;
// between subsequent accesses within a tile
int a_gl_rd_delta_i = a_gl_stride * (threads / a_gl_rd_delta_o);
// between shared memory writes
constexpr int a_sh_wr_delta = a_sh_stride * (threads / a_gl_rd_delta_o);
// between shared memory tile reads
constexpr int a_sh_rd_delta_o = 2 * ((threads / 32) / (thread_n_blocks / 4));
// within a shared memory tile
constexpr int a_sh_rd_delta_i = a_sh_stride * 16;
// overall size of a tile
constexpr int a_sh_stage = a_sh_stride * (16 * thread_m_blocks);
// number of shared write iterations for a tile
constexpr int a_sh_wr_iters = div_ceil(a_sh_stage, a_sh_wr_delta);
// B sizes/strides
int b_gl_stride = 16 * prob_n / (pack_factor * 4);
constexpr int b_sh_stride = ((thread_n_blocks * 16) * 16 / pack_factor) / 4;
constexpr int b_thread_vecs = num_bits == 4 ? 1 : 2;
constexpr int b_sh_stride_threads = b_sh_stride / b_thread_vecs;
int b_gl_rd_delta_o = b_gl_stride * thread_k_blocks;
int b_gl_rd_delta_i = b_gl_stride * (threads / b_sh_stride_threads);
constexpr int b_sh_wr_delta = threads * b_thread_vecs;
constexpr int b_sh_rd_delta = threads * b_thread_vecs;
constexpr int b_sh_stage = b_sh_stride * thread_k_blocks;
constexpr int b_sh_wr_iters = b_sh_stage / b_sh_wr_delta;
// Scale sizes/strides without act_order
int s_gl_stride = prob_n / 8;
constexpr int s_sh_stride = 16 * thread_n_blocks / 8;
constexpr int s_tb_groups =
!has_act_order && group_blocks != -1 && group_blocks < thread_k_blocks
? thread_k_blocks / group_blocks
: 1;
constexpr int s_sh_stage = s_tb_groups * s_sh_stride;
int s_gl_rd_delta = s_gl_stride;
// Scale size/strides with act_order
constexpr int tb_k = 16 * thread_k_blocks;
constexpr int g_idx_stage = has_act_order ? (tb_k * sizeof(int)) / 16 : 0;
// constexpr int act_s_row_stride = 1;
// int act_s_col_stride = act_s_row_stride * num_groups;
int act_s_col_stride = 1;
int act_s_col_warp_stride = act_s_col_stride * 8;
int tb_n_warps = thread_n_blocks / 4;
int act_s_col_tb_stride = act_s_col_warp_stride * tb_n_warps;
// Global A read index of current thread.
int a_gl_rd = a_gl_stride * (threadIdx.x / a_gl_rd_delta_o) +
(threadIdx.x % a_gl_rd_delta_o);
a_gl_rd += a_gl_rd_delta_o * slice_row;
// Shared write index of current thread.
int a_sh_wr = a_sh_stride * (threadIdx.x / a_gl_rd_delta_o) +
(threadIdx.x % a_gl_rd_delta_o);
// Shared read index.
int a_sh_rd =
a_sh_stride * ((threadIdx.x % 32) % 16) + (threadIdx.x % 32) / 16;
a_sh_rd += 2 * ((threadIdx.x / 32) / (thread_n_blocks / 4));
int b_gl_rd = b_gl_stride * (threadIdx.x / b_sh_stride_threads) +
(threadIdx.x % b_sh_stride_threads) * b_thread_vecs;
b_gl_rd += b_sh_stride * slice_col;
b_gl_rd += b_gl_rd_delta_o * slice_row;
int b_sh_wr = threadIdx.x * b_thread_vecs;
int b_sh_rd = threadIdx.x * b_thread_vecs;
// For act_order
constexpr int k_iter_size = tb_k / b_sh_wr_iters;
int slice_k_start = tb_k * slice_row;
int slice_k_finish = slice_k_start + tb_k * slice_iters;
int slice_k_start_shared_fetch = slice_k_start;
int slice_n_offset = act_s_col_tb_stride * slice_col;
// No act_order
int s_gl_rd;
if constexpr (!has_act_order) {
if constexpr (group_blocks == -1) {
s_gl_rd = s_sh_stride * slice_col + threadIdx.x;
} else {
s_gl_rd = s_gl_stride * ((thread_k_blocks * slice_row) / group_blocks) +
s_sh_stride * slice_col + threadIdx.x;
}
}
int s_sh_wr = threadIdx.x;
bool s_sh_wr_pred = threadIdx.x < s_sh_stride;
// We use a different scale layout for grouped and column-wise quantization as
// we scale a `half2` tile in column-major layout in the former and in
// row-major in the latter case.
int s_sh_rd;
if constexpr (group_blocks != -1)
s_sh_rd = 8 * ((threadIdx.x / 32) % (thread_n_blocks / 4)) +
(threadIdx.x % 32) / 4;
else
s_sh_rd = 8 * ((threadIdx.x / 32) % (thread_n_blocks / 4)) +
(threadIdx.x % 32) % 4;
// Precompute which thread should not read memory in which iterations; this is
// needed if there are more threads than required for a certain tilesize or
// when the batchsize is not a multiple of 16.
bool a_sh_wr_pred[a_sh_wr_iters];
#pragma unroll
for (int i = 0; i < a_sh_wr_iters; i++)
a_sh_wr_pred[i] = a_sh_wr_delta * i + a_sh_wr < a_sh_stride * prob_m;
// To ensure that writing and reading A tiles to/from shared memory, the
// latter in fragment format, is fully bank conflict free, we need to use a
// rather fancy XOR-based layout. The key here is that neither reads nor
// writes of the 16-byte `int4` blocks of 8 consecutive threads involve the
// same shared memory banks. Further, it seems (based on NSight-Compute) that
// each warp must also write a consecutive memory segment?
auto transform_a = [&](int i) {
int row = i / a_gl_rd_delta_o;
return a_gl_rd_delta_o * row + (i % a_gl_rd_delta_o) ^ row;
};
// Since the computation of this remapping is non-trivial and, due to our main
// loop unrolls, all shared memory accesses are static, we simply precompute
// both transformed reads and writes.
int a_sh_wr_trans[a_sh_wr_iters];
#pragma unroll
for (int i = 0; i < a_sh_wr_iters; i++)
a_sh_wr_trans[i] = transform_a(a_sh_wr_delta * i + a_sh_wr);
int a_sh_rd_trans[b_sh_wr_iters][thread_m_blocks];
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++) {
#pragma unroll
for (int j = 0; j < thread_m_blocks; j++)
a_sh_rd_trans[i][j] =
transform_a(a_sh_rd_delta_o * i + a_sh_rd_delta_i * j + a_sh_rd);
}
// Since B-accesses have non-constant stride they have to be computed at
// runtime; we break dependencies between subsequent accesses with a tile by
// maintining multiple pointers (we have enough registers), a tiny
// optimization.
const int4* B_ptr[b_sh_wr_iters];
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++)
B_ptr[i] = B + b_gl_rd_delta_i * i + b_gl_rd;
extern __shared__ int4 sh[];
// Shared memory storage for global fetch pipelines.
int4* sh_a = sh;
int4* sh_b = sh_a + (stages * a_sh_stage);
int4* sh_g_idx = sh_b + (stages * b_sh_stage);
int4* sh_s = sh_g_idx + (stages * g_idx_stage);
// Register storage for double buffer of shared memory reads.
FragA frag_a[2][thread_m_blocks];
I4 frag_b_quant[2][b_thread_vecs];
FragC frag_c[thread_m_blocks][4][2];
FragS frag_s[2][4]; // No act-order
FragS act_frag_s[2][4][4]; // For act-order
// Zero accumulators.
auto zero_accums = [&]() {
#pragma unroll
for (int i = 0; i < thread_m_blocks * 4 * 2 * 4; i++)
reinterpret_cast<float*>(frag_c)[i] = 0;
};
int sh_first_group_id = -1;
int sh_num_groups = -1;
constexpr int sh_max_num_groups = 32;
auto fetch_scales_to_shared = [&](bool is_async, int first_group_id,
int last_group_id) {
sh_first_group_id = first_group_id;
sh_num_groups = last_group_id - first_group_id + 1;
if (sh_num_groups < sh_max_num_groups) {
sh_num_groups = sh_max_num_groups;
}
if (sh_first_group_id + sh_num_groups > num_groups) {
sh_num_groups = num_groups - sh_first_group_id;
}
int row_offset = first_group_id * s_gl_stride;
if (is_async) {
for (int i = 0; i < sh_num_groups; i++) {
if (threadIdx.x < s_sh_stride) {
cp_async4_pred(&sh_s[(i * s_sh_stride) + threadIdx.x],
&scales_ptr[row_offset + (i * s_gl_stride) +
slice_n_offset + threadIdx.x]);
}
}
} else {
for (int i = 0; i < sh_num_groups; i++) {
if (threadIdx.x < s_sh_stride) {
sh_s[(i * s_sh_stride) + threadIdx.x] =
scales_ptr[row_offset + (i * s_gl_stride) + slice_n_offset +
threadIdx.x];
}
}
}
};
// Asynchronously fetch the next A, B and s tile from global to the next
// shared memory pipeline location.
auto fetch_to_shared = [&](int pipe, int a_off, bool pred = true) {
if (pred) {
int4* sh_a_stage = sh_a + a_sh_stage * pipe;
#pragma unroll
for (int i = 0; i < a_sh_wr_iters; i++) {
cp_async4_pred(
&sh_a_stage[a_sh_wr_trans[i]],
&A[a_gl_rd_delta_i * i + a_gl_rd + a_gl_rd_delta_o * a_off],
a_sh_wr_pred[i]);
}
int4* sh_b_stage = sh_b + b_sh_stage * pipe;
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++) {
#pragma unroll
for (int j = 0; j < b_thread_vecs; j++) {
cp_async4(&sh_b_stage[b_sh_wr_delta * i + b_sh_wr + j], B_ptr[i] + j);
}
B_ptr[i] += b_gl_rd_delta_o;
}
if constexpr (has_act_order) {
// Fetch g_idx thread-block portion
int full_pipe = a_off;
int cur_k = slice_k_start_shared_fetch + tb_k * full_pipe;
if (cur_k < prob_k && cur_k < slice_k_finish) {
int4* sh_g_idx_stage = sh_g_idx + g_idx_stage * pipe;
int4 const* cur_g_idx_stage_ptr =
reinterpret_cast<int4 const*>(&g_idx[cur_k]);
if (threadIdx.x < g_idx_stage) {
cp_async4_pred(&sh_g_idx_stage[threadIdx.x],
&cur_g_idx_stage_ptr[threadIdx.x]);
}
}
} else {
if constexpr (group_blocks != -1) {
int4* sh_s_stage = sh_s + s_sh_stage * pipe;
if constexpr (group_blocks >= thread_k_blocks) {
// Only fetch scales if this tile starts a new group
if (pipe % (group_blocks / thread_k_blocks) == 0) {
if (s_sh_wr_pred) {
cp_async4(&sh_s_stage[s_sh_wr], &scales_ptr[s_gl_rd]);
}
s_gl_rd += s_gl_rd_delta;
}
} else {
for (int i = 0; i < s_tb_groups; i++) {
if (s_sh_wr_pred) {
cp_async4(&sh_s_stage[i * s_sh_stride + s_sh_wr],
&scales_ptr[s_gl_rd]);
}
s_gl_rd += s_gl_rd_delta;
}
}
}
}
}
// Insert a fence even when we are winding down the pipeline to ensure that
// waiting is also correct at this point.
cp_async_fence();
};
// Wait until the next thread tile has been loaded to shared memory.
auto wait_for_stage = [&]() {
// We only have `stages - 2` active fetches since we are double buffering
// and can only issue the next fetch when it is guaranteed that the previous
// shared memory load is fully complete (as it may otherwise be
// overwritten).
cp_async_wait<stages - 2>();
__syncthreads();
};
// Load the next sub-tile from the current location in the shared memory pipe
// into the current register buffer.
auto fetch_to_registers = [&](int k, int pipe) {
int4* sh_a_stage = sh_a + a_sh_stage * pipe;
#pragma unroll
for (int i = 0; i < thread_m_blocks; i++)
ldsm4<scalar_t>(frag_a[k % 2][i],
&sh_a_stage[a_sh_rd_trans[k % b_sh_wr_iters][i]]);
int4* sh_b_stage = sh_b + b_sh_stage * pipe;
#pragma unroll
for (int i = 0; i < b_thread_vecs; i++) {
frag_b_quant[k % 2][i] = *reinterpret_cast<I4*>(
&sh_b_stage[b_sh_rd_delta * (k % b_sh_wr_iters) + b_sh_rd + i]);
}
};
bool is_same_group[stages];
int same_group_id[stages];
auto init_same_group = [&](int pipe) {
if constexpr (!has_act_order) {
is_same_group[pipe] = false;
same_group_id[pipe] = 0;
return;
}
int4* sh_g_idx_stage = sh_g_idx + g_idx_stage * pipe;
int* sh_g_idx_int_ptr = reinterpret_cast<int*>(sh_g_idx_stage);
int group_id_1 = sh_g_idx_int_ptr[0];
int group_id_2 = sh_g_idx_int_ptr[tb_k - 1];
is_same_group[pipe] = group_id_1 == group_id_2;
same_group_id[pipe] = group_id_1;
};
auto fetch_scales_to_registers = [&](int k, int full_pipe) {
int pipe = full_pipe % stages;
if constexpr (!has_act_order) {
// No act-order case
if constexpr (group_blocks != -1) {
if constexpr (group_blocks >= thread_k_blocks) {
int4* sh_s_stage =
sh_s + s_sh_stage * ((group_blocks / thread_k_blocks) *
(pipe / (group_blocks / thread_k_blocks)));
reinterpret_cast<int4*>(&frag_s[k % 2])[0] = sh_s_stage[s_sh_rd];
} else {
int warp_id = threadIdx.x / 32;
int n_warps = thread_n_blocks / 4;
int warp_row = warp_id / n_warps;
int cur_k = warp_row * 16;
cur_k += k_iter_size * (k % b_sh_wr_iters);
int k_blocks = cur_k / 16;
int cur_group_id = k_blocks / group_blocks;
int4* sh_s_stage = sh_s + s_sh_stage * pipe;
reinterpret_cast<int4*>(&frag_s[k % 2])[0] =
sh_s_stage[s_sh_rd + cur_group_id * s_sh_stride];
}
}
return;
}
// Act-order case
// Determine K of the "current" thread-block
int cur_k = slice_k_start + tb_k * full_pipe;
if (cur_k >= prob_k || cur_k >= slice_k_finish) {
return;
}
// Reset (to current thread-block) since we read g_idx portion from the
// shared memory
cur_k = 0;
// Progress to current iteration
cur_k += k_iter_size * (k % b_sh_wr_iters);
// Determine "position" inside the thread-block (based on warp and
// thread-id)
int warp_id = threadIdx.x / 32;
int n_warps =
thread_n_blocks / 4; // Each warp processes 4 16-size tiles over N
int warp_row = warp_id / n_warps;
int warp_col = warp_id % n_warps;
cur_k += warp_row * 16;
int th_id = threadIdx.x % 32;
cur_k += (th_id % 4) * 2; // Due to tensor-core layout for fp16 B matrix
int s_col_shift =
/*slice_n_offset +*/ (act_s_col_warp_stride * warp_col) +
(th_id / 4) * act_s_col_stride;
if (is_same_group[pipe]) {
if (k % 2 == 0) {
*(reinterpret_cast<int4*>(&(act_frag_s[k % 2][0][0]))) =
sh_s[(same_group_id[pipe] - sh_first_group_id) * s_sh_stride +
s_col_shift];
} else {
*(reinterpret_cast<int4*>(&(act_frag_s[k % 2][0][0]))) =
*(reinterpret_cast<int4*>(&(act_frag_s[(k - 1) % 2][0][0])));
}
for (int i = 1; i < 4; i++) {
*(reinterpret_cast<int4*>(&(act_frag_s[k % 2][i][0]))) =
*(reinterpret_cast<int4*>(&(act_frag_s[k % 2][0][0])));
}
return;
}
int4* sh_g_idx_stage = sh_g_idx + g_idx_stage * pipe;
int* sh_g_idx_int_ptr = reinterpret_cast<int*>(sh_g_idx_stage);
constexpr int k_frag_offsets[4] = {0, 1, 8,
9}; // Tensor core offsets per thread
#pragma unroll
for (int i = 0; i < 4; i++) {
int actual_k = cur_k + k_frag_offsets[i];
int group_id = sh_g_idx_int_ptr[actual_k];
int rel_group_id = group_id - sh_first_group_id;
*(reinterpret_cast<int4*>(&(act_frag_s[k % 2][i][0]))) =
sh_s[rel_group_id * s_sh_stride + s_col_shift];
}
};
// Execute the actual tensor core matmul of a sub-tile.
auto matmul = [&](int k) {
// We have the m dimension as the inner loop in order to encourage overlapping
// dequantization and matmul operations.
#pragma unroll
for (int j = 0; j < 4; j++) {
FragB frag_b0;
FragB frag_b1;
if constexpr (num_bits == 4) {
int b_quant = frag_b_quant[k % 2][0][j];
int b_quant_shift = b_quant >> 8;
frag_b0 = dequant_4bit<scalar_t>(b_quant);
frag_b1 = dequant_4bit<scalar_t>(b_quant_shift);
} else {
int* frag_b_quant_ptr = reinterpret_cast<int*>(frag_b_quant[k % 2]);
int b_quant_0 = frag_b_quant_ptr[j * 2 + 0];
int b_quant_1 = frag_b_quant_ptr[j * 2 + 1];
frag_b0 = dequant_8bit<scalar_t>(b_quant_0);
frag_b1 = dequant_8bit<scalar_t>(b_quant_1);
}
// Apply scale to frag_b0
if constexpr (has_act_order) {
scale4<scalar_t>(frag_b0, act_frag_s[k % 2][0][j],
act_frag_s[k % 2][1][j], act_frag_s[k % 2][2][j],
act_frag_s[k % 2][3][j], 0);
} else {
if constexpr (group_blocks != -1) {
scale<scalar_t>(frag_b0, frag_s[k % 2][j], 0);
}
}
// Apply scale to frag_b1
if constexpr (has_act_order) {
scale4<scalar_t>(frag_b1, act_frag_s[k % 2][0][j],
act_frag_s[k % 2][1][j], act_frag_s[k % 2][2][j],
act_frag_s[k % 2][3][j], 1);
} else {
if constexpr (group_blocks != -1) {
scale<scalar_t>(frag_b1, frag_s[k % 2][j], 1);
}
}
#pragma unroll
for (int i = 0; i < thread_m_blocks; i++) {
mma<scalar_t>(frag_a[k % 2][i], frag_b0, frag_c[i][j][0]);
mma<scalar_t>(frag_a[k % 2][i], frag_b1, frag_c[i][j][1]);
}
}
};
// Since we slice across the k dimension of a tile in order to increase the
// number of warps while keeping the n dimension of a tile reasonable, we have
// multiple warps that accumulate their partial sums of the same output
// location; which we have to reduce over in the end. We do in shared memory.
auto thread_block_reduce = [&]() {
constexpr int red_off = threads / b_sh_stride_threads / 2;
if (red_off >= 1) {
int red_idx = threadIdx.x / b_sh_stride_threads;
constexpr int red_sh_stride = b_sh_stride_threads * 4 * 2;
constexpr int red_sh_delta = b_sh_stride_threads;
int red_sh_rd = red_sh_stride * (threadIdx.x / b_sh_stride_threads) +
(threadIdx.x % b_sh_stride_threads);
// Parallel logarithmic shared memory reduction. We make sure to avoid any
// unnecessary read or write iterations, e.g., for two warps we write only
// once by warp 1 and read only once by warp 0.
#pragma unroll
for (int m_block = 0; m_block < thread_m_blocks; m_block++) {
#pragma unroll
for (int i = red_off; i > 0; i /= 2) {
if (i <= red_idx && red_idx < 2 * i) {
#pragma unroll
for (int j = 0; j < 4 * 2; j++) {
int red_sh_wr =
red_sh_delta * j + (red_sh_rd - red_sh_stride * i);
if (i < red_off) {
float* c_rd =
reinterpret_cast<float*>(&sh[red_sh_delta * j + red_sh_rd]);
float* c_wr = reinterpret_cast<float*>(&sh[red_sh_wr]);
#pragma unroll
for (int k = 0; k < 4; k++)
reinterpret_cast<FragC*>(frag_c)[4 * 2 * m_block + j][k] +=
c_rd[k] + c_wr[k];
}
sh[red_sh_wr] =
reinterpret_cast<int4*>(&frag_c)[4 * 2 * m_block + j];
}
}
__syncthreads();
}
if (red_idx == 0) {
#pragma unroll
for (int i = 0; i < 4 * 2; i++) {
float* c_rd =
reinterpret_cast<float*>(&sh[red_sh_delta * i + red_sh_rd]);
#pragma unroll
for (int j = 0; j < 4; j++)
reinterpret_cast<FragC*>(frag_c)[4 * 2 * m_block + i][j] +=
c_rd[j];
}
}
__syncthreads();
}
}
};
// Since multiple threadblocks may process parts of the same column slice, we
// finally have to globally reduce over the results. As the striped
// partitioning minimizes the number of such reductions and our outputs are
// usually rather small, we perform this reduction serially in L2 cache.
auto global_reduce = [&](bool first = false, bool last = false) {
// We are very careful here to reduce directly in the output buffer to
// maximize L2 cache utilization in this step. To do this, we write out
// results in FP16 (but still reduce with FP32 compute).
constexpr int active_threads = 32 * thread_n_blocks / 4;
if (threadIdx.x < active_threads) {
int c_gl_stride = prob_n / 8;
int c_gl_wr_delta_o = 8 * c_gl_stride;
int c_gl_wr_delta_i = 4 * (active_threads / 32);
int c_gl_wr = c_gl_stride * ((threadIdx.x % 32) / 4) +
4 * (threadIdx.x / 32) + threadIdx.x % 4;
c_gl_wr += (2 * thread_n_blocks) * slice_col;
constexpr int c_sh_wr_delta = active_threads;
int c_sh_wr = threadIdx.x;
int row = (threadIdx.x % 32) / 4;
if (!first) {
// Interestingly, doing direct global accesses here really seems to mess up
// the compiler and lead to slowdowns, hence we also use async-copies even
// though these fetches are not actually asynchronous.
#pragma unroll
for (int i = 0; i < thread_m_blocks * 4; i++) {
cp_async4_pred(
&sh[c_sh_wr + c_sh_wr_delta * i],
&C[c_gl_wr + c_gl_wr_delta_o * (i / 2) +
c_gl_wr_delta_i * (i % 2)],
i < (thread_m_blocks - 1) * 4 || 8 * (i / 2) + row < prob_m);
}
cp_async_fence();
cp_async_wait<0>();
}
#pragma unroll
for (int i = 0; i < thread_m_blocks * 4; i++) {
if (i < (thread_m_blocks - 1) * 4 || 8 * (i / 2) + row < prob_m) {
if (!first) {
int4 c_red = sh[c_sh_wr + i * c_sh_wr_delta];
#pragma unroll
for (int j = 0; j < 2 * 4; j++) {
reinterpret_cast<float*>(
&frag_c)[4 * 2 * 4 * (i / 4) + 4 * j + (i % 4)] +=
Dtype::num2float(reinterpret_cast<scalar_t*>(&c_red)[j]);
}
}
if (!last) {
int4 c;
#pragma unroll
for (int j = 0; j < 2 * 4; j++) {
reinterpret_cast<scalar_t*>(&c)[j] =
Dtype::float2num(reinterpret_cast<float*>(
&frag_c)[4 * 2 * 4 * (i / 4) + 4 * j + (i % 4)]);
}
C[c_gl_wr + c_gl_wr_delta_o * (i / 2) + c_gl_wr_delta_i * (i % 2)] =
c;
}
}
}
}
};
// Write out the reduce final result in the correct layout. We only actually
// reshuffle matrix fragments in this step, the reduction above is performed
// in fragment layout.
auto write_result = [&]() {
int c_gl_stride = prob_n / 8;
constexpr int c_sh_stride = 2 * thread_n_blocks + 1;
int c_gl_wr_delta = c_gl_stride * (threads / (2 * thread_n_blocks));
constexpr int c_sh_rd_delta =
c_sh_stride * (threads / (2 * thread_n_blocks));
int c_gl_wr = c_gl_stride * (threadIdx.x / (2 * thread_n_blocks)) +
(threadIdx.x % (2 * thread_n_blocks));
c_gl_wr += (2 * thread_n_blocks) * slice_col;
int c_sh_wr =
(4 * c_sh_stride) * ((threadIdx.x % 32) / 4) + (threadIdx.x % 32) % 4;
c_sh_wr += 32 * (threadIdx.x / 32);
int c_sh_rd = c_sh_stride * (threadIdx.x / (2 * thread_n_blocks)) +
(threadIdx.x % (2 * thread_n_blocks));
int c_gl_wr_end = c_gl_stride * prob_m;
// We first reorder in shared memory to guarantee the most efficient final
// global write patterns
auto write = [&](int idx, float c0, float c1, FragS& s) {
scalar_t2 res =
Dtype::nums2num2(Dtype::float2num(c0), Dtype::float2num(c1));
// For per-column quantization we finally apply the scale here (only for
// 4-bit)
if constexpr (!has_act_order && group_blocks == -1 && num_bits == 4) {
res = __hmul2(res, s[0]);
}
((scalar_t2*)sh)[idx] = res;
};
if (threadIdx.x / 32 < thread_n_blocks / 4) {
#pragma unroll
for (int i = 0; i < thread_m_blocks; i++) {
#pragma unroll
for (int j = 0; j < 4; j++) {
int wr = c_sh_wr + 8 * j;
write(wr + (4 * c_sh_stride) * 0 + 0, frag_c[i][j][0][0],
frag_c[i][j][0][1], frag_s[j / 2][2 * (j % 2) + 0]);
write(wr + (4 * c_sh_stride) * 8 + 0, frag_c[i][j][0][2],
frag_c[i][j][0][3], frag_s[j / 2][2 * (j % 2) + 0]);
write(wr + (4 * c_sh_stride) * 0 + 4, frag_c[i][j][1][0],
frag_c[i][j][1][1], frag_s[j / 2][2 * (j % 2) + 1]);
write(wr + (4 * c_sh_stride) * 8 + 4, frag_c[i][j][1][2],
frag_c[i][j][1][3], frag_s[j / 2][2 * (j % 2) + 1]);
}
c_sh_wr += 16 * (4 * c_sh_stride);
}
}
__syncthreads();
#pragma unroll
for (int i = 0;
i < div_ceil(16 * thread_m_blocks, threads / (2 * thread_n_blocks));
i++) {
if (c_gl_wr < c_gl_wr_end) {
C[c_gl_wr] = sh[c_sh_rd];
c_gl_wr += c_gl_wr_delta;
c_sh_rd += c_sh_rd_delta;
}
}
};
// Start global fetch and register load pipelines.
auto start_pipes = [&]() {
#pragma unroll
for (int i = 0; i < stages - 1; i++) {
if (has_act_order && i == 0) {
int last_g_idx = slice_k_start + stages * tb_k * 2;
if (last_g_idx >= prob_k) {
last_g_idx = prob_k - 1;
}
fetch_scales_to_shared(true, g_idx[slice_k_start], g_idx[last_g_idx]);
}
fetch_to_shared(i, i, i < slice_iters);
}
zero_accums();
wait_for_stage();
init_same_group(0);
fetch_to_registers(0, 0);
fetch_scales_to_registers(0, 0);
a_gl_rd += a_gl_rd_delta_o * (stages - 1);
slice_k_start_shared_fetch += tb_k * (stages - 1);
};
if (slice_iters) {
start_pipes();
}
// Main loop.
while (slice_iters) {
// We unroll over both the global fetch and the register load pipeline to
// ensure all shared memory accesses are static. Note that both pipelines
// have even length meaning that the next iteration will always start at
// index 0.
#pragma unroll
for (int pipe = 0; pipe < stages;) {
#pragma unroll
for (int k = 0; k < b_sh_wr_iters; k++) {
fetch_to_registers(k + 1, pipe % stages);
fetch_scales_to_registers(k + 1, pipe);
if (k == b_sh_wr_iters - 2) {
fetch_to_shared((pipe + stages - 1) % stages, pipe,
slice_iters >= stages);
pipe++;
wait_for_stage();
init_same_group(pipe % stages);
}
matmul(k);
}
slice_iters--;
if (slice_iters == 0) {
break;
}
}
a_gl_rd += a_gl_rd_delta_o * stages;
slice_k_start += tb_k * stages;
slice_k_start_shared_fetch += tb_k * stages;
if constexpr (has_act_order) {
int first_group_id = g_idx[slice_k_start];
int last_g_idx = slice_k_start + stages * tb_k * 2;
if (last_g_idx >= prob_k) {
last_g_idx = prob_k - 1;
}
int last_group_id = g_idx[last_g_idx];
if (last_group_id >= sh_first_group_id + sh_num_groups) {
fetch_scales_to_shared(false, first_group_id, last_group_id);
__syncthreads();
}
}
// Process results and, if necessary, proceed to the next column slice.
// While this pattern may not be the most readable, other ways of writing
// the loop seemed to noticeably worse performance after compilation.
if (slice_iters == 0) {
cp_async_wait<0>();
bool last = slice_idx == slice_count - 1;
// For per-column scales, we only fetch them here in the final step before
// write-out
if constexpr (!has_act_order && group_blocks == -1) {
if constexpr (num_bits == 8) {
if (s_sh_wr_pred) {
cp_async4(&sh_s[s_sh_wr], &scales_ptr[s_gl_rd]);
}
cp_async_fence();
} else {
if (last) {
if (s_sh_wr_pred) {
cp_async4(&sh_s[s_sh_wr], &scales_ptr[s_gl_rd]);
}
cp_async_fence();
}
}
}
thread_block_reduce();
if constexpr (!has_act_order && group_blocks == -1) {
if constexpr (num_bits == 8) {
cp_async_wait<0>();
__syncthreads();
if (threadIdx.x / 32 < thread_n_blocks / 4) {
reinterpret_cast<int4*>(&frag_s)[0] = sh_s[s_sh_rd + 0];
reinterpret_cast<int4*>(&frag_s)[1] = sh_s[s_sh_rd + 4];
}
} else {
if (last) {
cp_async_wait<0>();
__syncthreads();
if (threadIdx.x / 32 < thread_n_blocks / 4) {
reinterpret_cast<int4*>(&frag_s)[0] = sh_s[s_sh_rd + 0];
reinterpret_cast<int4*>(&frag_s)[1] = sh_s[s_sh_rd + 4];
}
}
}
}
// For 8-bit channelwise, we apply the scale before the global reduction
// that converts the fp32 results to fp16 (so that we avoid possible
// overflow in fp16)
if constexpr (!has_act_order && group_blocks == -1 && num_bits == 8) {
if (threadIdx.x / 32 < thread_n_blocks / 4) {
#pragma unroll
for (int i = 0; i < thread_m_blocks; i++) {
#pragma unroll
for (int j = 0; j < 4; j++) {
scale_float<scalar_t>(
reinterpret_cast<float*>(&frag_c[i][j][0][0]),
frag_s[j / 2][2 * (j % 2) + 0]);
scale_float<scalar_t>(
reinterpret_cast<float*>(&frag_c[i][j][0][2]),
frag_s[j / 2][2 * (j % 2) + 0]);
scale_float<scalar_t>(
reinterpret_cast<float*>(&frag_c[i][j][1][0]),
frag_s[j / 2][2 * (j % 2) + 1]);
scale_float<scalar_t>(
reinterpret_cast<float*>(&frag_c[i][j][1][2]),
frag_s[j / 2][2 * (j % 2) + 1]);
}
}
}
}
if (slice_count > 1) { // only globally reduce if there is more than one
// block in a slice
barrier_acquire(&locks[slice_col], slice_idx);
global_reduce(slice_idx == 0, last);
barrier_release(&locks[slice_col], last);
}
if (last) // only the last block in a slice actually writes the result
write_result();
slice_row = 0;
slice_col_par++;
slice_col++;
init_slice();
if (slice_iters) {
a_gl_rd = a_gl_stride * (threadIdx.x / a_gl_rd_delta_o) +
(threadIdx.x % a_gl_rd_delta_o);
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++)
B_ptr[i] += b_sh_stride - b_gl_rd_delta_o * k_tiles;
if (slice_col == 0) {
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++) B_ptr[i] -= b_gl_stride;
}
// Update slice k/n for scales loading
if constexpr (has_act_order) {
slice_k_start = tb_k * slice_row;
slice_k_finish = slice_k_start + tb_k * slice_iters;
slice_k_start_shared_fetch = slice_k_start;
slice_n_offset = act_s_col_tb_stride * slice_col;
} else {
s_gl_rd = s_sh_stride * slice_col + threadIdx.x;
}
start_pipes();
}
}
}
}
#define __CALL_IF(NUM_BITS, THREAD_M_BLOCKS, THREAD_N_BLOCKS, \
THREAD_K_BLOCKS, HAS_ACT_ORDER, GROUP_BLOCKS, NUM_THREADS) \
else if (num_bits == NUM_BITS && thread_m_blocks == THREAD_M_BLOCKS && \
thread_n_blocks == THREAD_N_BLOCKS && \
thread_k_blocks == THREAD_K_BLOCKS && \
has_act_order == HAS_ACT_ORDER && group_blocks == GROUP_BLOCKS && \
num_threads == NUM_THREADS) { \
cudaFuncSetAttribute( \
Marlin<scalar_t, NUM_BITS, NUM_THREADS, THREAD_M_BLOCKS, \
THREAD_N_BLOCKS, THREAD_K_BLOCKS, pipe_stages, HAS_ACT_ORDER, \
GROUP_BLOCKS>, \
cudaFuncAttributeMaxDynamicSharedMemorySize, max_shared_mem); \
Marlin<scalar_t, NUM_BITS, NUM_THREADS, THREAD_M_BLOCKS, \
THREAD_N_BLOCKS, THREAD_K_BLOCKS, pipe_stages, HAS_ACT_ORDER, \
GROUP_BLOCKS><<<blocks, NUM_THREADS, max_shared_mem, stream>>>( \
A_ptr, B_ptr, C_ptr, s_ptr, g_idx_ptr, num_groups, prob_m, prob_n, \
prob_k, locks); \
}
typedef struct {
int thread_k;
int thread_n;
int num_threads;
} thread_config_t;
typedef struct {
int max_m_blocks;
thread_config_t tb_cfg;
} exec_config_t;
thread_config_t small_batch_thread_configs[] = {
// Ordered by priority
// thread_k, thread_n, num_threads
{128, 128, 256},
{64, 128, 128},
{128, 64, 128},
};
thread_config_t large_batch_thread_configs[] = {
// Ordered by priority
// thread_k, thread_n, num_threads
{64, 256, 256},
{64, 128, 128},
{128, 64, 128},
};
int get_scales_cache_size(thread_config_t const& th_config, int prob_m,
int prob_n, int prob_k, int num_bits, int group_size,
bool has_act_order, bool is_k_full) {
bool cache_scales_chunk = has_act_order && !is_k_full;
int tb_n = th_config.thread_n;
int tb_k = th_config.thread_k;
// Get max scale groups per thread-block
int tb_groups;
if (group_size == -1) {
tb_groups = 1;
} else if (group_size == 0) {
tb_groups = div_ceil(tb_k, 32); // Worst case is 32 group size
} else {
tb_groups = div_ceil(tb_k, group_size);
}
if (cache_scales_chunk) {
int load_groups =
tb_groups * pipe_stages * 2; // Chunk size is 2x pipeline over dim K
load_groups = max(load_groups, 32); // We load at least 32 scale groups
return load_groups * tb_n * 2;
} else {
int tb_scales = tb_groups * tb_n * 2;
return tb_scales * pipe_stages;
}
}
bool is_valid_cache_size(thread_config_t const& th_config, int max_m_blocks,
int prob_m, int prob_n, int prob_k, int num_bits,
int scales_cache_size, int max_shared_mem) {
int pack_factor = 32 / num_bits;
// Get B size
int tb_k = th_config.thread_k;
int tb_n = th_config.thread_n;
int b_size = (tb_k * tb_n / pack_factor) * 4;
// Get A size
int m_blocks = div_ceil(prob_m, 16);
int tb_max_m = 16;
while (true) {
if (m_blocks >= max_m_blocks) {
tb_max_m *= max_m_blocks;
break;
}
max_m_blocks--;
if (max_m_blocks == 0) {
TORCH_CHECK(false, "Unexpected m_blocks = ", m_blocks);
}
}
int a_size = (tb_max_m * tb_k) * 2;
float pipe_size = (a_size + b_size) * pipe_stages;
TORCH_CHECK(max_shared_mem / 2 > scales_cache_size); // Sanity
return pipe_size < 0.95f * (max_shared_mem - scales_cache_size);
}
bool is_valid_config(thread_config_t const& th_config, int max_m_blocks,
int prob_m, int prob_n, int prob_k, int num_bits,
int group_size, bool has_act_order, bool is_k_full,
int max_shared_mem) {
// Sanity
if (th_config.thread_k == -1 || th_config.thread_n == -1 ||
th_config.num_threads == -1) {
return false;
}
// Verify K/N are divisible by thread K/N
if (prob_k % th_config.thread_k != 0 || prob_n % th_config.thread_n != 0) {
return false;
}
// Verify min for thread K/N
if (th_config.thread_n < min_thread_n || th_config.thread_k < min_thread_k) {
return false;
}
// num_threads must be at least 128 (= 4 warps)
if (th_config.num_threads < 128) {
return false;
}
// Determine cache for scales
int scales_cache_size =
get_scales_cache_size(th_config, prob_m, prob_n, prob_k, num_bits,
group_size, has_act_order, is_k_full);
// Check that pipeline fits into cache
if (!is_valid_cache_size(th_config, max_m_blocks, prob_m, prob_n, prob_k,
num_bits, scales_cache_size, max_shared_mem)) {
return false;
}
return true;
}
exec_config_t determine_thread_config(int prob_m, int prob_n, int prob_k,
int num_bits, int group_size,
bool has_act_order, bool is_k_full,
int max_shared_mem) {
int max_m_blocks = 4;
while (max_m_blocks > 0) {
if (prob_m <= 16) {
for (auto th_config : small_batch_thread_configs) {
if (is_valid_config(th_config, max_m_blocks, prob_m, prob_n, prob_k,
num_bits, group_size, has_act_order, is_k_full,
max_shared_mem)) {
return exec_config_t{max_m_blocks, th_config};
}
}
} else {
for (auto th_config : large_batch_thread_configs) {
if (is_valid_config(th_config, max_m_blocks, prob_m, prob_n, prob_k,
num_bits, group_size, has_act_order, is_k_full,
max_shared_mem)) {
return exec_config_t{max_m_blocks, th_config};
}
}
}
max_m_blocks--; // Process less M blocks per invocation to reduce cache
// usage
}
return exec_config_t{0, {-1, -1, -1}};
}
#define CALL_IF(NUM_BITS, N_BLOCKS, K_BLOCKS, NUM_THREADS) \
__CALL_IF(NUM_BITS, 1, N_BLOCKS, K_BLOCKS, true, 0, NUM_THREADS) \
__CALL_IF(NUM_BITS, 2, N_BLOCKS, K_BLOCKS, true, 0, NUM_THREADS) \
__CALL_IF(NUM_BITS, 3, N_BLOCKS, K_BLOCKS, true, 0, NUM_THREADS) \
__CALL_IF(NUM_BITS, 4, N_BLOCKS, K_BLOCKS, true, 0, NUM_THREADS) \
\
__CALL_IF(NUM_BITS, 1, N_BLOCKS, K_BLOCKS, false, -1, NUM_THREADS) \
__CALL_IF(NUM_BITS, 1, N_BLOCKS, K_BLOCKS, false, 2, NUM_THREADS) \
__CALL_IF(NUM_BITS, 1, N_BLOCKS, K_BLOCKS, false, 4, NUM_THREADS) \
__CALL_IF(NUM_BITS, 1, N_BLOCKS, K_BLOCKS, false, 8, NUM_THREADS) \
\
__CALL_IF(NUM_BITS, 2, N_BLOCKS, K_BLOCKS, false, -1, NUM_THREADS) \
__CALL_IF(NUM_BITS, 2, N_BLOCKS, K_BLOCKS, false, 2, NUM_THREADS) \
__CALL_IF(NUM_BITS, 2, N_BLOCKS, K_BLOCKS, false, 4, NUM_THREADS) \
__CALL_IF(NUM_BITS, 2, N_BLOCKS, K_BLOCKS, false, 8, NUM_THREADS) \
\
__CALL_IF(NUM_BITS, 3, N_BLOCKS, K_BLOCKS, false, -1, NUM_THREADS) \
__CALL_IF(NUM_BITS, 3, N_BLOCKS, K_BLOCKS, false, 2, NUM_THREADS) \
__CALL_IF(NUM_BITS, 3, N_BLOCKS, K_BLOCKS, false, 4, NUM_THREADS) \
__CALL_IF(NUM_BITS, 3, N_BLOCKS, K_BLOCKS, false, 8, NUM_THREADS) \
\
__CALL_IF(NUM_BITS, 4, N_BLOCKS, K_BLOCKS, false, -1, NUM_THREADS) \
__CALL_IF(NUM_BITS, 4, N_BLOCKS, K_BLOCKS, false, 2, NUM_THREADS) \
__CALL_IF(NUM_BITS, 4, N_BLOCKS, K_BLOCKS, false, 4, NUM_THREADS) \
__CALL_IF(NUM_BITS, 4, N_BLOCKS, K_BLOCKS, false, 8, NUM_THREADS)
template <typename scalar_t>
void marlin_mm_f16i4(const void* A, const void* B, void* C, void* s,
void* g_idx, void* perm, void* a_tmp, int prob_m,
int prob_n, int prob_k, void* workspace, int num_bits,
bool has_act_order, bool is_k_full, int num_groups,
int group_size, int dev, cudaStream_t stream, int thread_k,
int thread_n, int sms, int max_par) {
TORCH_CHECK(num_bits == 4 || num_bits == 8,
"num_bits must be 4 or 8. Got = ", num_bits);
TORCH_CHECK(prob_m > 0 && prob_n > 0 && prob_k > 0, "Invalid MNK = [", prob_m,
", ", prob_n, ", ", prob_k, "]");
int tot_m = prob_m;
int tot_m_blocks = div_ceil(tot_m, 16);
int pad = 16 * tot_m_blocks - tot_m;
if (sms == -1) {
cudaDeviceGetAttribute(&sms, cudaDevAttrMultiProcessorCount, dev);
}
int max_shared_mem = 0;
cudaDeviceGetAttribute(&max_shared_mem,
cudaDevAttrMaxSharedMemoryPerBlockOptin, dev);
TORCH_CHECK(max_shared_mem > 0);
// Set thread config
exec_config_t exec_cfg;
if (thread_k != -1 && thread_n != -1) {
// User-defined config
exec_cfg =
exec_config_t{4, thread_config_t{thread_k, thread_n, default_threads}};
} else {
// Auto config
exec_cfg =
determine_thread_config(prob_m, prob_n, prob_k, num_bits, group_size,
has_act_order, is_k_full, max_shared_mem);
}
TORCH_CHECK(exec_cfg.max_m_blocks > 0 &&
is_valid_config(exec_cfg.tb_cfg, exec_cfg.max_m_blocks,
prob_m, prob_n, prob_k, num_bits, group_size,
has_act_order, is_k_full, max_shared_mem),
"Invalid thread config: max_m_blocks = ", exec_cfg.max_m_blocks,
", thread_k = ", exec_cfg.tb_cfg.thread_k,
", thread_n = ", exec_cfg.tb_cfg.thread_n,
", num_threads = ", exec_cfg.tb_cfg.num_threads, " for MKN = [",
prob_m, ", ", prob_k, ", ", prob_n, "] and num_bits = ", num_bits,
", group_size = ", group_size,
", has_act_order = ", has_act_order, ", is_k_full = ", is_k_full,
", max_shared_mem = ", max_shared_mem);
int num_threads = exec_cfg.tb_cfg.num_threads;
thread_k = exec_cfg.tb_cfg.thread_k;
thread_n = exec_cfg.tb_cfg.thread_n;
int thread_k_blocks = thread_k / 16;
int thread_n_blocks = thread_n / 16;
int blocks = sms;
TORCH_CHECK(prob_n % thread_n == 0, "prob_n = ", prob_n,
" is not divisible by thread_n = ", thread_n);
TORCH_CHECK(prob_k % thread_k == 0, "prob_k = ", prob_k,
" is not divisible by thread_k = ", thread_k);
int group_blocks = 0;
if (has_act_order) {
if (is_k_full) {
TORCH_CHECK(group_size != -1);
group_blocks = group_size / 16;
TORCH_CHECK(prob_k % group_blocks == 0, "prob_k = ", prob_k,
" is not divisible by group_blocks = ", group_blocks);
} else {
TORCH_CHECK(group_size == 0);
group_blocks = 0;
}
} else {
if (group_size == -1) {
group_blocks = -1;
} else {
group_blocks = group_size / 16;
TORCH_CHECK(prob_k % group_blocks == 0, "prob_k = ", prob_k,
" is not divisible by group_blocks = ", group_blocks);
}
}
const int4* A_ptr = (const int4*)A;
const int4* B_ptr = (const int4*)B;
int4* C_ptr = (int4*)C;
const int4* s_ptr = (const int4*)s;
const int* g_idx_ptr = (const int*)g_idx;
const int* perm_ptr = (const int*)perm;
int4* a_tmp_ptr = (int4*)a_tmp;
int* locks = (int*)workspace;
if (has_act_order) {
// Permute A columns
int block_rows = div_ceil(prob_m, blocks);
permute_cols_kernel<<<blocks, default_threads, 0, stream>>>(
A_ptr, perm_ptr, a_tmp_ptr, prob_m, prob_k, block_rows);
A_ptr = a_tmp_ptr;
}
// If we have a full K, then we can run the non-act-order version of Marlin
// (since the weight rows are reordered by increasing group ids, and by having
// a full K, we have full original groups)
if (is_k_full) {
has_act_order = false;
}
// Main loop
for (int i = 0; i < tot_m_blocks; i += exec_cfg.max_m_blocks) {
int thread_m_blocks = tot_m_blocks - i;
prob_m = tot_m - 16 * i;
int par = 1;
if (thread_m_blocks > exec_cfg.max_m_blocks) {
// Note that parallel > 1 currently only works for inputs without any
// padding
par = (16 * thread_m_blocks - pad) / (16 * exec_cfg.max_m_blocks);
if (par > max_par) par = max_par;
prob_m = (16 * exec_cfg.max_m_blocks) * par;
i += exec_cfg.max_m_blocks * (par - 1);
thread_m_blocks = exec_cfg.max_m_blocks;
}
// Define kernel configurations
if (false) {
}
CALL_IF(4, 32, 2, 256)
CALL_IF(4, 16, 4, 256)
CALL_IF(4, 8, 8, 256)
CALL_IF(4, 8, 4, 128)
CALL_IF(4, 4, 8, 128)
CALL_IF(8, 32, 2, 256)
CALL_IF(8, 16, 4, 256)
CALL_IF(8, 8, 8, 256)
CALL_IF(8, 8, 4, 128)
CALL_IF(8, 4, 8, 128)
else {
TORCH_CHECK(false, "Unsupported shapes: MNK = [" + str(prob_m) + ", " +
str(prob_n) + ", " + str(prob_k) + "]" +
", has_act_order = " + str(has_act_order) +
", num_groups = " + str(num_groups) +
", group_size = " + str(group_size) +
", thread_m_blocks = " + str(thread_m_blocks) +
", thread_n_blocks = " + str(thread_n_blocks) +
", thread_k_blocks = " + str(thread_k_blocks));
}
A_ptr += 16 * thread_m_blocks * (prob_k / 8) * par;
C_ptr += 16 * thread_m_blocks * (prob_n / 8) * par;
}
}
} // namespace gptq_marlin
torch::Tensor gptq_marlin_gemm(torch::Tensor& a, torch::Tensor& b_q_weight,
torch::Tensor& b_scales, torch::Tensor& g_idx,
torch::Tensor& perm, torch::Tensor& workspace,
int64_t num_bits, int64_t size_m, int64_t size_n,
int64_t size_k, bool is_k_full) {
// Verify num_bits
TORCH_CHECK(num_bits == 4 || num_bits == 8,
"num_bits must be 4 or 8. Got = ", num_bits);
int pack_factor = 32 / num_bits;
// Verify A
TORCH_CHECK(a.size(0) == size_m, "Shape mismatch: a.size(0) = ", a.size(0),
", size_m = ", size_m);
TORCH_CHECK(a.size(1) == size_k, "Shape mismatch: a.size(1) = ", a.size(1),
", size_k = ", size_k);
// Verify B
TORCH_CHECK(size_k % gptq_marlin::tile_size == 0, "size_k = ", size_k,
" is not divisible by tile_size = ", gptq_marlin::tile_size);
TORCH_CHECK((size_k / gptq_marlin::tile_size) == b_q_weight.size(0),
"Shape mismatch: b_q_weight.size(0) = ", b_q_weight.size(0),
", size_k = ", size_k, ", tile_size = ", gptq_marlin::tile_size);
TORCH_CHECK(b_q_weight.size(1) % gptq_marlin::tile_size == 0,
"b_q_weight.size(1) = ", b_q_weight.size(1),
" is not divisible by tile_size = ", gptq_marlin::tile_size);
int actual_size_n =
(b_q_weight.size(1) / gptq_marlin::tile_size) * pack_factor;
TORCH_CHECK(size_n == actual_size_n, "size_n = ", size_n,
", actual_size_n = ", actual_size_n);
// Verify device and strides
TORCH_CHECK(a.device().is_cuda(), "A is not on GPU");
TORCH_CHECK(a.is_contiguous(), "A is not contiguous");
TORCH_CHECK(b_q_weight.device().is_cuda(), "b_q_weight is not on GPU");
TORCH_CHECK(b_q_weight.is_contiguous(), "b_q_weight is not contiguous");
TORCH_CHECK(b_scales.device().is_cuda(), "b_scales is not on GPU");
TORCH_CHECK(b_scales.is_contiguous(), "b_scales is not contiguous");
TORCH_CHECK(g_idx.device().is_cuda(), "g_idx is not on GPU");
TORCH_CHECK(g_idx.is_contiguous(), "g_idx is not contiguous");
TORCH_CHECK(perm.device().is_cuda(), "perm is not on GPU");
TORCH_CHECK(perm.is_contiguous(), "perm is not contiguous");
// Alloc buffers
const at::cuda::OptionalCUDAGuard device_guard(device_of(a));
auto options = torch::TensorOptions().dtype(a.dtype()).device(a.device());
torch::Tensor c = torch::empty({size_m, size_n}, options);
torch::Tensor a_tmp = torch::empty({size_m, size_k}, options);
// thread_k: `k` size of a thread_tile in `weights` (can usually be left as
// auto -1)
int thread_k = -1;
// thread_n: `n` size of a thread_tile in `weights` (can usually be left as
// auto -1)
int thread_n = -1;
// sms: number of SMs to use for the kernel (can usually be left as auto -1)
int sms = -1;
// Verify g_idx and perm
TORCH_CHECK((g_idx.size(0) == 0 && perm.size(0) == 0) ||
(g_idx.size(0) == size_k && perm.size(0) == size_k),
"Unexpected g_idx.size(0) = ", g_idx.size(0),
" and perm.size(0) = ", perm.size(0),
", where size_k = ", size_k);
// Detect groupsize and act_order
int num_groups = -1;
int group_size = -1;
bool has_act_order = g_idx.size(0) != 0;
int b_rank = b_scales.sizes().size();
TORCH_CHECK(b_rank == 2, "b_scales rank = ", b_rank, " is not 2");
TORCH_CHECK(b_scales.size(1) == size_n, "b_scales dim 1 = ", b_scales.size(1),
" is not size_n = ", size_n);
num_groups = b_scales.size(0);
if (has_act_order) {
if (is_k_full) {
TORCH_CHECK(num_groups > 1, "For act_order, num_groups must be > 1");
TORCH_CHECK(size_k % num_groups == 0, "size_k = ", size_k,
", is not divisible by num_groups = ", num_groups);
group_size = size_k / num_groups;
} else {
group_size = 0;
}
} else {
if (num_groups > 1) {
TORCH_CHECK(
size_k % num_groups == 0, "size_k = ", size_k,
", is not divisible by b_scales.size(0) = ", b_scales.size(0));
group_size = size_k / num_groups;
} else {
group_size = -1;
}
}
// Verify workspace size
TORCH_CHECK(
size_n % gptq_marlin::min_thread_n == 0, "size_n = ", size_n,
", is not divisible by min_thread_n = ", gptq_marlin::min_thread_n);
int min_workspace_size =
(size_n / gptq_marlin::min_thread_n) * gptq_marlin::max_par;
TORCH_CHECK(workspace.numel() >= min_workspace_size,
"workspace.numel = ", workspace.numel(),
" is below min_workspace_size = ", min_workspace_size);
int dev = a.get_device();
if (a.scalar_type() == at::ScalarType::Half) {
gptq_marlin::marlin_mm_f16i4<half>(
a.data_ptr<at::Half>(), b_q_weight.data_ptr(), c.data_ptr<at::Half>(),
b_scales.data_ptr<at::Half>(), g_idx.data_ptr(), perm.data_ptr(),
a_tmp.data_ptr<at::Half>(), size_m, size_n, size_k,
workspace.data_ptr(), num_bits, has_act_order, is_k_full, num_groups,
group_size, dev, at::cuda::getCurrentCUDAStream(dev), thread_k,
thread_n, sms, gptq_marlin::max_par);
} else if (a.scalar_type() == at::ScalarType::BFloat16) {
gptq_marlin::marlin_mm_f16i4<nv_bfloat16>(
a.data_ptr<at::BFloat16>(), b_q_weight.data_ptr(),
c.data_ptr<at::BFloat16>(), b_scales.data_ptr<at::BFloat16>(),
g_idx.data_ptr(), perm.data_ptr(), a_tmp.data_ptr<at::BFloat16>(),
size_m, size_n, size_k, workspace.data_ptr(), num_bits, has_act_order,
is_k_full, num_groups, group_size, dev,
at::cuda::getCurrentCUDAStream(dev), thread_k, thread_n, sms,
gptq_marlin::max_par);
} else {
TORCH_CHECK(false, "gpt_marlin_gemm only supports bfloat16 and float16");
}
return c;
}
#endif
server/marlin/marlin_kernels/gptq_marlin.cuh 0 → 100644
View file @ 093a27c5
#pragma once
#include <torch/all.h>
#include <ATen/cuda/CUDAContext.h>
#include <c10/cuda/CUDAGuard.h>
#include <cuda.h>
#include <cuda_fp16.h>
#include <cuda_runtime.h>
#include <iostream>
namespace gptq_marlin {
// 8 warps are a good choice since every SM has 4 schedulers and having more
// than 1 warp per schedule allows some more latency hiding. At the same time,
// we want relatively few warps to have many registers per warp and small tiles.
static constexpr int default_threads = 256;
static constexpr int pipe_stages =
4; // 4 pipeline stages fit into shared memory
static constexpr int min_thread_n = 64;
static constexpr int min_thread_k = 64;
static constexpr int tile_size = 16;
static constexpr int max_par = 16;
template <typename T, int n>
struct Vec {
T elems[n];
__device__ T& operator[](int i) { return elems[i]; }
};
using I4 = Vec<int, 4>;
constexpr int div_ceil(int a, int b) { return (a + b - 1) / b; }
#if defined(__CUDA_ARCH__) && __CUDA_ARCH__ < 800
// No support for async
#else
__device__ inline void cp_async4_pred(void* smem_ptr, const void* glob_ptr,
bool pred = true) {
const int BYTES = 16;
uint32_t smem = static_cast<uint32_t>(__cvta_generic_to_shared(smem_ptr));
asm volatile(
"{\n"
" .reg .pred p;\n"
" setp.ne.b32 p, %0, 0;\n"
" @p cp.async.cg.shared.global [%1], [%2], %3;\n"
"}\n" ::"r"((int)pred),
"r"(smem), "l"(glob_ptr), "n"(BYTES));
}
__device__ inline void cp_async4(void* smem_ptr, const void* glob_ptr) {
const int BYTES = 16;
uint32_t smem = static_cast<uint32_t>(__cvta_generic_to_shared(smem_ptr));
asm volatile(
"{\n"
" cp.async.cg.shared.global [%0], [%1], %2;\n"
"}\n" ::"r"(smem),
"l"(glob_ptr), "n"(BYTES));
}
__device__ inline void cp_async_fence() {
asm volatile("cp.async.commit_group;\n" ::);
}
template <int n>
__device__ inline void cp_async_wait() {
asm volatile("cp.async.wait_group %0;\n" ::"n"(n));
}
#endif
} // namespace gptq_marlin
server/marlin/marlin_kernels/gptq_marlin_dtypes.cuh 0 → 100644
View file @ 093a27c5
#ifndef _data_types_cuh
#define _data_types_cuh
#include "gptq_marlin.cuh"
#include <cuda_fp16.h>
#include <cuda_bf16.h>
namespace gptq_marlin {
template <typename scalar_t>
class ScalarType {};
template <>
class ScalarType<half> {
public:
using scalar_t = half;
using scalar_t2 = half2;
// Matrix fragments for tensor core instructions; their precise layout is
// documented here:
// https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#matrix-fragments-for-mma-m16n8k16-with-floating-point-type
using FragA = Vec<half2, 4>;
using FragB = Vec<half2, 2>;
using FragC = Vec<float, 4>;
using FragS = Vec<half2, 1>;
static __device__ float inline num2float(const half x) {
return __half2float(x);
}
static __device__ half2 inline num2num2(const half x) {
return __half2half2(x);
}
static __device__ half2 inline nums2num2(const half x1, const half x2) {
return __halves2half2(x1, x2);
}
static __host__ __device__ half inline float2num(const float x) {
return __float2half(x);
}
};
template <>
class ScalarType<nv_bfloat16> {
public:
using scalar_t = nv_bfloat16;
using scalar_t2 = nv_bfloat162;
using FragA = Vec<nv_bfloat162, 4>;
using FragB = Vec<nv_bfloat162, 2>;
using FragC = Vec<float, 4>;
using FragS = Vec<nv_bfloat162, 1>;
#if defined(__CUDA_ARCH__) && __CUDA_ARCH__ >= 800
static __device__ float inline num2float(const nv_bfloat16 x) {
return __bfloat162float(x);
}
static __device__ nv_bfloat162 inline num2num2(const nv_bfloat16 x) {
return __bfloat162bfloat162(x);
}
static __device__ nv_bfloat162 inline nums2num2(const nv_bfloat16 x1,
const nv_bfloat16 x2) {
return __halves2bfloat162(x1, x2);
}
static __host__ __device__ nv_bfloat16 inline float2num(const float x) {
return __float2bfloat16(x);
}
#endif
};
} // namespace gptq_marlin
#endif
server/marlin/marlin_kernels/gptq_marlin_repack.cu 0 → 100644
View file @ 093a27c5
#include "gptq_marlin.cuh"
namespace gptq_marlin {
static constexpr int repack_stages = 8;
static constexpr int repack_threads = 256;
static constexpr int tile_k_size = tile_size;
static constexpr int tile_n_size = tile_k_size * 4;
#if defined(__CUDA_ARCH__) && __CUDA_ARCH__ < 800
template <int const num_threads, int const num_bits, bool const has_perm>
__global__ void marlin_repack_kernel(
uint32_t const* __restrict__ b_q_weight_ptr,
uint32_t const* __restrict__ perm_ptr, uint32_t* __restrict__ out_ptr,
int size_k, int size_n) {}
} // namespace gptq_marlin
torch::Tensor gptq_marlin_repack(torch::Tensor& b_q_weight, torch::Tensor& perm,
int64_t size_k, int64_t size_n,
int64_t num_bits) {
TORCH_CHECK_NOT_IMPLEMENTED(
false, "marlin_repack_from_gptq(..) requires CUDA_ARCH >= 8.0");
return torch::empty({1, 1});
}
#else
template <int const num_threads, int const num_bits, bool const has_perm>
__global__ void marlin_repack_kernel(
uint32_t const* __restrict__ b_q_weight_ptr,
uint32_t const* __restrict__ perm_ptr, uint32_t* __restrict__ out_ptr,
int size_k, int size_n) {
constexpr int pack_factor = 32 / num_bits;
int k_tiles = size_k / tile_k_size;
int n_tiles = size_n / tile_n_size;
int block_k_tiles = div_ceil(k_tiles, gridDim.x);
int start_k_tile = blockIdx.x * block_k_tiles;
if (start_k_tile >= k_tiles) {
return;
}
int finish_k_tile = min(start_k_tile + block_k_tiles, k_tiles);
// Wait until the next thread tile has been loaded to shared memory.
auto wait_for_stage = [&]() {
// We only have `stages - 2` active fetches since we are double buffering
// and can only issue the next fetch when it is guaranteed that the previous
// shared memory load is fully complete (as it may otherwise be
// overwritten).
cp_async_wait<repack_stages - 2>();
__syncthreads();
};
extern __shared__ int4 sh[];
constexpr int perm_size = tile_k_size / 4;
int4* sh_perm_ptr = sh;
int4* sh_pipe_ptr = sh_perm_ptr;
if constexpr (has_perm) {
sh_pipe_ptr += perm_size;
}
constexpr int tile_ints = tile_k_size / pack_factor;
constexpr int stage_n_threads = tile_n_size / 4;
constexpr int stage_k_threads = has_perm ? tile_k_size : tile_ints;
constexpr int stage_size = stage_k_threads * stage_n_threads;
auto load_perm_to_shared = [&](int k_tile_id) {
int first_k_int4 = (k_tile_id * tile_k_size) / 4;
int4 const* perm_int4_ptr = reinterpret_cast<int4 const*>(perm_ptr);
if (threadIdx.x < perm_size) {
sh_perm_ptr[threadIdx.x] = perm_int4_ptr[first_k_int4 + threadIdx.x];
}
__syncthreads();
};
auto fetch_to_shared = [&](int pipe, int k_tile_id, int n_tile_id) {
if (n_tile_id >= n_tiles) {
cp_async_fence();
return;
}
int first_n = n_tile_id * tile_n_size;
int4* sh_ptr = sh_pipe_ptr + stage_size * pipe;
if constexpr (has_perm) {
if (threadIdx.x < stage_size) {
int k_id = threadIdx.x / stage_n_threads;
int n_id = threadIdx.x % stage_n_threads;
uint32_t const* sh_perm_int_ptr =
reinterpret_cast<uint32_t const*>(sh_perm_ptr);
int src_k = sh_perm_int_ptr[k_id];
int src_k_packed = src_k / pack_factor;
cp_async4(
&sh_ptr[k_id * stage_n_threads + n_id],
reinterpret_cast<int4 const*>(&(
b_q_weight_ptr[src_k_packed * size_n + first_n + (n_id * 4)])));
}
} else {
if (threadIdx.x < stage_size) {
int k_id = threadIdx.x / stage_n_threads;
int n_id = threadIdx.x % stage_n_threads;
int first_k = k_tile_id * tile_k_size;
int first_k_packed = first_k / pack_factor;
cp_async4(&sh_ptr[k_id * stage_n_threads + n_id],
reinterpret_cast<int4 const*>(
&(b_q_weight_ptr[(first_k_packed + k_id) * size_n +
first_n + (n_id * 4)])));
}
}
cp_async_fence();
};
auto repack_tile = [&](int pipe, int k_tile_id, int n_tile_id) {
if (n_tile_id >= n_tiles) {
return;
}
int warp_id = threadIdx.x / 32;
int th_id = threadIdx.x % 32;
if (warp_id >= 4) {
return;
}
int tc_col = th_id / 4;
int tc_row = (th_id % 4) * 2;
constexpr int tc_offsets[4] = {0, 1, 8, 9};
int cur_n = warp_id * 16 + tc_col;
constexpr int sh_stride = 64;
constexpr uint32_t mask = (1 << num_bits) - 1;
int4* sh_stage_ptr = sh_pipe_ptr + stage_size * pipe;
uint32_t* sh_stage_int_ptr = reinterpret_cast<uint32_t*>(sh_stage_ptr);
uint32_t* sh_perm_int_ptr = reinterpret_cast<uint32_t*>(sh_perm_ptr);
uint32_t vals[8];
if constexpr (has_perm) {
for (int i = 0; i < 4; i++) {
int k_idx = tc_row + tc_offsets[i];
uint32_t src_k = sh_perm_int_ptr[k_idx];
uint32_t src_k_pos = src_k % pack_factor;
uint32_t b1_val = sh_stage_int_ptr[k_idx * sh_stride + cur_n];
uint32_t b1_cur_val = (b1_val >> (src_k_pos * num_bits)) & mask;
uint32_t b2_val = sh_stage_int_ptr[k_idx * sh_stride + cur_n + 8];
uint32_t b2_cur_val = (b2_val >> (src_k_pos * num_bits)) & mask;
vals[i] = b1_cur_val;
vals[4 + i] = b2_cur_val;
}
} else {
uint32_t b1_vals[tile_ints];
uint32_t b2_vals[tile_ints];
#pragma unroll
for (int i = 0; i < tile_ints; i++) {
b1_vals[i] = sh_stage_int_ptr[cur_n + sh_stride * i];
b2_vals[i] = sh_stage_int_ptr[cur_n + 8 + sh_stride * i];
}
#pragma unroll
for (int i = 0; i < 4; i++) {
int cur_elem = tc_row + tc_offsets[i];
int cur_int = cur_elem / pack_factor;
int cur_pos = cur_elem % pack_factor;
vals[i] = (b1_vals[cur_int] >> (cur_pos * num_bits)) & mask;
vals[4 + i] = (b2_vals[cur_int] >> (cur_pos * num_bits)) & mask;
}
}
constexpr int tile_size = tile_k_size * tile_n_size / pack_factor;
int out_offset = (k_tile_id * n_tiles + n_tile_id) * tile_size;
// Result of:
// https://github.com/NVIDIA/FasterTransformer/blob/main/src/fastertransformer/cutlass_extensions/include/cutlass_extensions/interleaved_numeric_conversion.h
if constexpr (num_bits == 4) {
constexpr int pack_idx[8] = {0, 2, 4, 6, 1, 3, 5, 7};
uint32_t res = 0;
#pragma unroll
for (int i = 0; i < 8; i++) {
res |= vals[pack_idx[i]] << (i * 4);
}
out_ptr[out_offset + th_id * 4 + warp_id] = res;
} else {
constexpr int pack_idx[4] = {0, 2, 1, 3};
uint32_t res1 = 0;
uint32_t res2 = 0;
#pragma unroll
for (int i = 0; i < 4; i++) {
res1 |= vals[pack_idx[i]] << (i * 8);
res2 |= vals[4 + pack_idx[i]] << (i * 8);
}
out_ptr[out_offset + th_id * 8 + (warp_id * 2) + 0] = res1;
out_ptr[out_offset + th_id * 8 + (warp_id * 2) + 1] = res2;
}
};
auto start_pipes = [&](int k_tile_id, int n_tile_id) {
#pragma unroll
for (int pipe = 0; pipe < repack_stages - 1; pipe++) {
fetch_to_shared(pipe, k_tile_id, n_tile_id + pipe);
}
wait_for_stage();
};
#pragma unroll
for (int k_tile_id = start_k_tile; k_tile_id < finish_k_tile; k_tile_id++) {
int n_tile_id = 0;
if constexpr (has_perm) {
load_perm_to_shared(k_tile_id);
}
start_pipes(k_tile_id, n_tile_id);
while (n_tile_id < n_tiles) {
#pragma unroll
for (int pipe = 0; pipe < repack_stages; pipe++) {
fetch_to_shared((pipe + repack_stages - 1) % repack_stages, k_tile_id,
n_tile_id + pipe + repack_stages - 1);
repack_tile(pipe, k_tile_id, n_tile_id + pipe);
wait_for_stage();
}
n_tile_id += repack_stages;
}
}
}
} // namespace gptq_marlin
#define CALL_IF(NUM_BITS, HAS_PERM) \
else if (num_bits == NUM_BITS && has_perm == HAS_PERM) { \
cudaFuncSetAttribute( \
gptq_marlin::marlin_repack_kernel<gptq_marlin::repack_threads, \
NUM_BITS, HAS_PERM>, \
cudaFuncAttributeMaxDynamicSharedMemorySize, max_shared_mem); \
gptq_marlin::marlin_repack_kernel<gptq_marlin::repack_threads, NUM_BITS, \
HAS_PERM> \
<<<blocks, gptq_marlin::repack_threads, max_shared_mem, stream>>>( \
b_q_weight_ptr, perm_ptr, out_ptr, size_k, size_n); \
}
torch::Tensor gptq_marlin_repack(torch::Tensor& b_q_weight, torch::Tensor& perm,
int64_t size_k, int64_t size_n,
int64_t num_bits) {
// Verify compatibility with marlin tile of 16x64
TORCH_CHECK(size_k % gptq_marlin::tile_k_size == 0, "size_k = ", size_k,
" is not divisible by tile_k_size = ", gptq_marlin::tile_k_size);
TORCH_CHECK(size_n % gptq_marlin::tile_n_size == 0, "size_n = ", size_n,
" is not divisible by tile_n_size = ", gptq_marlin::tile_n_size);
TORCH_CHECK(num_bits == 4 || num_bits == 8,
"num_bits must be 4 or 8. Got = ", num_bits);
int const pack_factor = 32 / num_bits;
// Verify B
TORCH_CHECK((size_k / pack_factor) == b_q_weight.size(0),
"Shape mismatch: b_q_weight.size(0) = ", b_q_weight.size(0),
", size_k = ", size_k, ", pack_factor = ", pack_factor);
TORCH_CHECK(b_q_weight.size(1) == size_n,
"b_q_weight.size(1) = ", b_q_weight.size(1),
" is not size_n = ", size_n);
// Verify device and strides
TORCH_CHECK(b_q_weight.device().is_cuda(), "b_q_weight is not on GPU");
TORCH_CHECK(b_q_weight.is_contiguous(), "b_q_weight is not contiguous");
TORCH_CHECK(b_q_weight.dtype() == at::kInt, "b_q_weight type is not kInt");
TORCH_CHECK(perm.device().is_cuda(), "perm is not on GPU");
TORCH_CHECK(perm.is_contiguous(), "perm is not contiguous");
TORCH_CHECK(perm.dtype() == at::kInt, "perm type is not at::kInt");
// Alloc buffers
const at::cuda::OptionalCUDAGuard device_guard(device_of(b_q_weight));
auto options = torch::TensorOptions()
.dtype(b_q_weight.dtype())
.device(b_q_weight.device());
torch::Tensor out =
torch::empty({size_k / gptq_marlin::tile_size,
size_n * gptq_marlin::tile_size / pack_factor},
options);
// Detect if there is act_order
bool has_perm = perm.size(0) != 0;
// Get ptrs
uint32_t const* b_q_weight_ptr =
reinterpret_cast<uint32_t const*>(b_q_weight.data_ptr());
uint32_t const* perm_ptr = reinterpret_cast<uint32_t const*>(perm.data_ptr());
uint32_t* out_ptr = reinterpret_cast<uint32_t*>(out.data_ptr());
// Get dev info
int dev = b_q_weight.get_device();
cudaStream_t stream = at::cuda::getCurrentCUDAStream(dev);
int blocks;
cudaDeviceGetAttribute(&blocks, cudaDevAttrMultiProcessorCount, dev);
int max_shared_mem = 0;
cudaDeviceGetAttribute(&max_shared_mem,
cudaDevAttrMaxSharedMemoryPerBlockOptin, dev);
TORCH_CHECK(max_shared_mem > 0);
if (false) {
}
CALL_IF(4, false)
CALL_IF(4, true)
CALL_IF(8, false)
CALL_IF(8, true)
else {
TORCH_CHECK(false, "Unsupported repack config: num_bits = ", num_bits,
", has_perm = ", has_perm);
}
return out;
}
#endif
server/marlin/marlin_kernels/marlin_cuda_kernel.cu 0 → 100644
View file @ 093a27c5
/*
* Modified by Neural Magic
* Copyright (C) Marlin.2024 Elias Frantar
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <torch/all.h>
#include <ATen/cuda/CUDAContext.h>
#include <c10/cuda/CUDAGuard.h>
#include <cuda.h>
#include <cuda_fp16.h>
#include <cuda_runtime.h>
#include <iostream>
template <typename T>
inline std::string str(T x) {
return std::to_string(x);
}
namespace marlin {
constexpr int ceildiv(int a, int b) { return (a + b - 1) / b; }
#if defined(__CUDA_ARCH__) && __CUDA_ARCH__ >= 800
// Instances of `Vec` are used to organize groups of >>registers<<, as needed
// for instance as inputs to tensor core operations. Consequently, all
// corresponding index accesses must be compile-time constants, which is why we
// extensively use `#pragma unroll` throughout the kernel code to guarantee
// this.
template <typename T, int n>
struct Vec {
T elems[n];
__device__ T& operator[](int i) { return elems[i]; }
};
using I4 = Vec<int, 4>;
// Matrix fragments for tensor core instructions; their precise layout is
// documented here:
// https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#matrix-fragments-for-mma-m16n8k16-with-floating-point-type
using FragA = Vec<half2, 4>;
using FragB = Vec<half2, 2>;
using FragC = Vec<float, 4>;
using FragS = Vec<half2, 1>; // quantization scales
// Predicated asynchronous global->shared copy; used for inputs A where we apply
// predication to handle batchsizes that are not multiples of 16.
__device__ inline void cp_async4_pred(void* smem_ptr, const void* glob_ptr,
bool pred = true) {
const int BYTES = 16;
uint32_t smem = static_cast<uint32_t>(__cvta_generic_to_shared(smem_ptr));
asm volatile(
"{\n"
" .reg .pred p;\n"
" setp.ne.b32 p, %0, 0;\n"
" @p cp.async.cg.shared.global [%1], [%2], %3;\n"
"}\n" ::"r"((int)pred),
"r"(smem), "l"(glob_ptr), "n"(BYTES));
}
// Asynchronous global->shared copy
__device__ inline void cp_async4(void* smem_ptr, const void* glob_ptr) {
const int BYTES = 16;
uint32_t smem = static_cast<uint32_t>(__cvta_generic_to_shared(smem_ptr));
asm volatile(
"{\n"
" cp.async.cg.shared.global [%0], [%1], %2;\n"
"}\n" ::"r"(smem),
"l"(glob_ptr), "n"(BYTES));
}
// Async copy fence.
__device__ inline void cp_async_fence() {
asm volatile("cp.async.commit_group;\n" ::);
}
// Wait until at most `n` async copy stages are still pending.
template <int n>
__device__ inline void cp_async_wait() {
asm volatile("cp.async.wait_group %0;\n" ::"n"(n));
}
// m16n8k16 tensor core mma instruction with fp16 inputs and fp32
// output/accumulation.
__device__ inline void mma(const FragA& a_frag, const FragB& frag_b,
FragC& frag_c) {
const uint32_t* a = reinterpret_cast<const uint32_t*>(&a_frag);
const uint32_t* b = reinterpret_cast<const uint32_t*>(&frag_b);
float* c = reinterpret_cast<float*>(&frag_c);
asm volatile(
"mma.sync.aligned.m16n8k16.row.col.f32.f16.f16.f32 "
"{%0,%1,%2,%3}, {%4,%5,%6,%7}, {%8,%9}, {%10,%11,%12,%13};\n"
: "=f"(c[0]), "=f"(c[1]), "=f"(c[2]), "=f"(c[3])
: "r"(a[0]), "r"(a[1]), "r"(a[2]), "r"(a[3]), "r"(b[0]), "r"(b[1]),
"f"(c[0]), "f"(c[1]), "f"(c[2]), "f"(c[3]));
}
// Instruction for loading a full 16x16 matrix fragment of operand A from shared
// memory, directly in tensor core layout.
__device__ inline void ldsm4(FragA& frag_a, const void* smem_ptr) {
uint32_t* a = reinterpret_cast<uint32_t*>(&frag_a);
uint32_t smem = static_cast<uint32_t>(__cvta_generic_to_shared(smem_ptr));
asm volatile("ldmatrix.sync.aligned.m8n8.x4.shared.b16 {%0,%1,%2,%3}, [%4];\n"
: "=r"(a[0]), "=r"(a[1]), "=r"(a[2]), "=r"(a[3])
: "r"(smem));
}
// Lookup-table based 3-input logical operation; explicitly used for
// dequantization as the compiler does not seem to automatically recognize it in
// all cases.
template <int lut>
__device__ inline int lop3(int a, int b, int c) {
int res;
asm volatile("lop3.b32 %0, %1, %2, %3, %4;\n"
: "=r"(res)
: "r"(a), "r"(b), "r"(c), "n"(lut));
return res;
}
// Efficiently dequantize an int32 value into a full B-fragment of 4 fp16
// values. We mostly follow the strategy in the link below, with some small
// changes:
// https://github.com/NVIDIA/FasterTransformer/blob/main/src/fastertransformer/cutlass_extensions/include/cutlass_extensions/interleaved_numeric_conversion.h
__device__ inline FragB dequant(int q) {
const int LO = 0x000f000f;
const int HI = 0x00f000f0;
const int EX = 0x64006400;
// Guarantee that the `(a & b) | c` operations are LOP3s.
int lo = lop3<(0xf0 & 0xcc) | 0xaa>(q, LO, EX);
int hi = lop3<(0xf0 & 0xcc) | 0xaa>(q, HI, EX);
// We want signed int4 outputs, hence we fuse the `-8` symmetric zero point
// directly into `SUB` and `ADD`.
const int SUB = 0x64086408;
const int MUL = 0x2c002c00;
const int ADD = 0xd480d480;
FragB frag_b;
frag_b[0] = __hsub2(*reinterpret_cast<half2*>(&lo),
*reinterpret_cast<const half2*>(&SUB));
frag_b[1] = __hfma2(*reinterpret_cast<half2*>(&hi),
*reinterpret_cast<const half2*>(&MUL),
*reinterpret_cast<const half2*>(&ADD));
return frag_b;
}
// Multiply dequantized values by the corresponding quantization scale; used
// only for grouped quantization.
__device__ inline void scale(FragB& frag_b, FragS& frag_s, int i) {
half2 s = __half2half2(reinterpret_cast<__half*>(&frag_s)[i]);
frag_b[0] = __hmul2(frag_b[0], s);
frag_b[1] = __hmul2(frag_b[1], s);
}
// Wait until barrier reaches `count`, then lock for current threadblock.
__device__ inline void barrier_acquire(int* lock, int count) {
if (threadIdx.x == 0) {
int state = -1;
do
// Guarantee that subsequent writes by this threadblock will be visible
// globally.
asm volatile("ld.global.acquire.gpu.b32 %0, [%1];\n"
: "=r"(state)
: "l"(lock));
while (state != count);
}
__syncthreads();
}
// Release barrier and increment visitation count.
__device__ inline void barrier_release(int* lock, bool reset = false) {
__syncthreads();
if (threadIdx.x == 0) {
if (reset) {
lock[0] = 0;
return;
}
int val = 1;
// Make sure that all writes since acquiring this barrier are visible
// globally, while releasing the barrier.
asm volatile("fence.acq_rel.gpu;\n");
asm volatile("red.relaxed.gpu.global.add.s32 [%0], %1;\n"
:
: "l"(lock), "r"(val));
}
}
template <const int threads, // number of threads in a threadblock
const int thread_m_blocks, // number of 16x16 blocks in the m
// dimension (batchsize) of the
// threadblock
const int thread_n_blocks, // same for n dimension (output)
const int thread_k_blocks, // same for k dimension (reduction)
const int stages, // number of stages for the async global->shared
// fetch pipeline
const int group_blocks = -1 // number of consecutive 16x16 blocks
// with a separate quantization scale
>
__global__ void Marlin(
const int4* __restrict__ A, // fp16 input matrix of shape mxk
const int4* __restrict__ B, // 4bit quantized weight matrix of shape kxn
int4* __restrict__ C, // fp16 output buffer of shape mxn
const int4* __restrict__ s, // fp16 quantization scales of shape
// (k/groupsize)xn
int prob_m, // batch dimension m
int prob_n, // output dimension n
int prob_k, // reduction dimension k
int* locks // extra global storage for barrier synchronization
) {
// Each threadblock processes one "stripe" of the B matrix with (roughly) the
// same size, which might involve multiple column "slices" (of width 16 *
// `thread_n_blocks`). Stripes are defined as shown in the 3x3 matrix 5 SM
// example:
// 0 1 3
// 0 2 3
// 1 2 4
// While this kind of partitioning makes things somewhat more complicated, it
// ensures good utilization of all SMs for many kinds of shape and GPU
// configurations, while requiring as few slow global cross-threadblock
// reductions as possible.
// For larger GEMMs we run multiple batchsize 64 versions in parallel for a
// better partitioning with less reductions
int parallel = 1;
if (prob_m > 16 * thread_m_blocks) {
parallel = prob_m / (16 * thread_m_blocks);
prob_m = 16 * thread_m_blocks;
}
int k_tiles = prob_k / 16 / thread_k_blocks;
int n_tiles = prob_n / 16 / thread_n_blocks;
int iters = ceildiv(k_tiles * n_tiles * parallel, gridDim.x);
// Ensure that the number of tiles in each stripe is a multiple of the
// groupsize; this avoids an annoying special case where a stripe starts in
// the middle of group.
if (group_blocks != -1)
iters = (group_blocks / thread_k_blocks) *
ceildiv(iters, (group_blocks / thread_k_blocks));
int slice_row = (iters * blockIdx.x) % k_tiles;
int slice_col_par = (iters * blockIdx.x) / k_tiles;
int slice_col = slice_col_par;
int slice_iters; // number of threadblock tiles in the current slice
int slice_count =
0; // total number of active threadblocks in the current slice
int slice_idx; // index of threadblock in current slice; numbered bottom to
// top
// We can easily implement parallel problem execution by just remapping
// indices and advancing global pointers
if (slice_col_par >= n_tiles) {
A += (slice_col_par / n_tiles) * 16 * thread_m_blocks * prob_k / 8;
C += (slice_col_par / n_tiles) * 16 * thread_m_blocks * prob_n / 8;
locks += (slice_col_par / n_tiles) * n_tiles;
slice_col = slice_col_par % n_tiles;
}
// Compute all information about the current slice which is required for
// synchronization.
auto init_slice = [&]() {
slice_iters =
iters * (blockIdx.x + 1) - (k_tiles * slice_col_par + slice_row);
if (slice_iters < 0 || slice_col_par >= n_tiles * parallel) slice_iters = 0;
if (slice_iters == 0) return;
if (slice_row + slice_iters > k_tiles) slice_iters = k_tiles - slice_row;
slice_count = 1;
slice_idx = 0;
int col_first = iters * ceildiv(k_tiles * slice_col_par, iters);
if (col_first <= k_tiles * (slice_col_par + 1)) {
int col_off = col_first - k_tiles * slice_col_par;
slice_count = ceildiv(k_tiles - col_off, iters);
if (col_off > 0) slice_count++;
int delta_first = iters * blockIdx.x - col_first;
if (delta_first < 0 || (col_off == 0 && delta_first == 0))
slice_idx = slice_count - 1;
else {
slice_idx = slice_count - 1 - delta_first / iters;
if (col_off > 0) slice_idx--;
}
}
if (slice_col == n_tiles) {
A += 16 * thread_m_blocks * prob_k / 8;
C += 16 * thread_m_blocks * prob_n / 8;
locks += n_tiles;
slice_col = 0;
}
};
init_slice();
int a_gl_stride = prob_k / 8; // stride of the A matrix in global memory
// We typically use `constexpr` to indicate that this value is a compile-time
// constant
constexpr int a_sh_stride =
16 * thread_k_blocks / 8; // stride of an A matrix tile in shared memory
constexpr int a_gl_rd_delta_o =
16 * thread_k_blocks /
8; // delta between subsequent A tiles in global memory
int a_gl_rd_delta_i =
a_gl_stride *
(threads / a_gl_rd_delta_o); // between subsequent accesses within a tile
constexpr int a_sh_wr_delta =
a_sh_stride *
(threads / a_gl_rd_delta_o); // between shared memory writes
constexpr int a_sh_rd_delta_o =
2 * ((threads / 32) /
(thread_n_blocks / 4)); // between shared memory tile reads
constexpr int a_sh_rd_delta_i =
a_sh_stride * 16; // within a shared memory tile
constexpr int a_sh_stage =
a_sh_stride * (16 * thread_m_blocks); // overall size of a tile
constexpr int a_sh_wr_iters =
ceildiv(a_sh_stage,
a_sh_wr_delta); // number of shared write iterations for a tile
int b_gl_stride = 16 * prob_n / 32;
constexpr int b_sh_stride = 32 * thread_n_blocks / 4;
int b_gl_rd_delta_o = b_gl_stride * thread_k_blocks;
int b_gl_rd_delta_i = b_gl_stride * (threads / b_sh_stride);
constexpr int b_sh_wr_delta = threads;
constexpr int b_sh_rd_delta = threads;
constexpr int b_sh_stage = b_sh_stride * thread_k_blocks;
constexpr int b_sh_wr_iters = b_sh_stage / b_sh_wr_delta;
int s_gl_stride = prob_n / 8;
constexpr int s_sh_stride = 16 * thread_n_blocks / 8;
constexpr int s_sh_stage = s_sh_stride;
int s_gl_rd_delta = s_gl_stride;
// Global A read index of current thread.
int a_gl_rd = a_gl_stride * (threadIdx.x / a_gl_rd_delta_o) +
(threadIdx.x % a_gl_rd_delta_o);
a_gl_rd += a_gl_rd_delta_o * slice_row;
// Shared write index of current thread.
int a_sh_wr = a_sh_stride * (threadIdx.x / a_gl_rd_delta_o) +
(threadIdx.x % a_gl_rd_delta_o);
// Shared read index.
int a_sh_rd =
a_sh_stride * ((threadIdx.x % 32) % 16) + (threadIdx.x % 32) / 16;
a_sh_rd += 2 * ((threadIdx.x / 32) / (thread_n_blocks / 4));
int b_gl_rd =
b_gl_stride * (threadIdx.x / b_sh_stride) + (threadIdx.x % b_sh_stride);
b_gl_rd += b_sh_stride * slice_col;
b_gl_rd += b_gl_rd_delta_o * slice_row;
int b_sh_wr = threadIdx.x;
int b_sh_rd = threadIdx.x;
int s_gl_rd = s_gl_stride * ((thread_k_blocks * slice_row) / group_blocks) +
s_sh_stride * slice_col + threadIdx.x;
int s_sh_wr = threadIdx.x;
int s_sh_rd;
// We use a different scale layout for grouped and column-wise quantization as
// we scale a `half2` tile in column-major layout in the former and in
// row-major in the latter case.
if (group_blocks != -1)
s_sh_rd = 8 * ((threadIdx.x / 32) % (thread_n_blocks / 4)) +
(threadIdx.x % 32) / 4;
else
s_sh_rd = 8 * ((threadIdx.x / 32) % (thread_n_blocks / 4)) +
(threadIdx.x % 32) % 4;
// Precompute which thread should not read memory in which iterations; this is
// needed if there are more threads than required for a certain tilesize or
// when the batchsize is not a multiple of 16.
bool a_sh_wr_pred[a_sh_wr_iters];
#pragma unroll
for (int i = 0; i < a_sh_wr_iters; i++)
a_sh_wr_pred[i] = a_sh_wr_delta * i + a_sh_wr < a_sh_stride * prob_m;
bool s_sh_wr_pred = threadIdx.x < s_sh_stride;
// To ensure that writing and reading A tiles to/from shared memory, the
// latter in fragment format, is fully bank conflict free, we need to use a
// rather fancy XOR-based layout. The key here is that neither reads nor
// writes of the 16-byte `int4` blocks of 8 consecutive threads involve the
// same shared memory banks. Further, it seems (based on NSight-Compute) that
// each warp must also write a consecutive memory segment?
auto transform_a = [&](int i) {
int row = i / a_gl_rd_delta_o;
return a_gl_rd_delta_o * row + (i % a_gl_rd_delta_o) ^ row;
};
// Since the computation of this remapping is non-trivial and, due to our main
// loop unrolls, all shared memory accesses are static, we simply precompute
// both transformed reads and writes.
int a_sh_wr_trans[a_sh_wr_iters];
#pragma unroll
for (int i = 0; i < a_sh_wr_iters; i++)
a_sh_wr_trans[i] = transform_a(a_sh_wr_delta * i + a_sh_wr);
int a_sh_rd_trans[b_sh_wr_iters][thread_m_blocks];
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++) {
#pragma unroll
for (int j = 0; j < thread_m_blocks; j++)
a_sh_rd_trans[i][j] =
transform_a(a_sh_rd_delta_o * i + a_sh_rd_delta_i * j + a_sh_rd);
}
// Since B-accesses have non-constant stride they have to be computed at
// runtime; we break dependencies between subsequent accesses with a tile by
// maintining multiple pointers (we have enough registers), a tiny
// optimization.
const int4* B_ptr[b_sh_wr_iters];
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++)
B_ptr[i] = B + b_gl_rd_delta_i * i + b_gl_rd;
extern __shared__ int4 sh[];
// Shared memory storage for global fetch pipelines.
int4* sh_a = sh;
int4* sh_b = sh_a + (stages * a_sh_stage);
int4* sh_s = sh_b + (stages * b_sh_stage);
// Register storage for double buffer of shared memory reads.
FragA frag_a[2][thread_m_blocks];
I4 frag_b_quant[2];
FragC frag_c[thread_m_blocks][4][2];
FragS frag_s[2][4];
// Zero accumulators.
auto zero_accums = [&]() {
#pragma unroll
for (int i = 0; i < thread_m_blocks * 4 * 2 * 4; i++)
reinterpret_cast<float*>(frag_c)[i] = 0;
};
// Asynchronously fetch the next A, B and s tile from global to the next
// shared memory pipeline location.
auto fetch_to_shared = [&](int pipe, int a_off, bool pred = true) {
if (pred) {
int4* sh_a_stage = sh_a + a_sh_stage * pipe;
#pragma unroll
for (int i = 0; i < a_sh_wr_iters; i++) {
cp_async4_pred(
&sh_a_stage[a_sh_wr_trans[i]],
&A[a_gl_rd_delta_i * i + a_gl_rd + a_gl_rd_delta_o * a_off],
a_sh_wr_pred[i]);
}
int4* sh_b_stage = sh_b + b_sh_stage * pipe;
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++) {
cp_async4(&sh_b_stage[b_sh_wr_delta * i + b_sh_wr], B_ptr[i]);
B_ptr[i] += b_gl_rd_delta_o;
}
// Only fetch scales if this tile starts a new group
if (group_blocks != -1 && pipe % (group_blocks / thread_k_blocks) == 0) {
int4* sh_s_stage = sh_s + s_sh_stage * pipe;
if (s_sh_wr_pred) cp_async4(&sh_s_stage[s_sh_wr], &s[s_gl_rd]);
s_gl_rd += s_gl_rd_delta;
}
}
// Insert a fence even when we are winding down the pipeline to ensure that
// waiting is also correct at this point.
cp_async_fence();
};
// Wait until the next thread tile has been loaded to shared memory.
auto wait_for_stage = [&]() {
// We only have `stages - 2` active fetches since we are double buffering
// and can only issue the next fetch when it is guaranteed that the previous
// shared memory load is fully complete (as it may otherwise be
// overwritten).
cp_async_wait<stages - 2>();
__syncthreads();
};
// Load the next sub-tile from the current location in the shared memory pipe
// into the current register buffer.
auto fetch_to_registers = [&](int k, int pipe) {
// It may seem inefficient that we reload the groups for every sub-tile;
// however, this does not seem to be a significant bottleneck, while some
// theoretically better attempts have lead to bad instruction ordering by
// the compiler and correspondingly a noticeable drop in performance.
if (group_blocks != -1) {
int4* sh_s_stage =
sh_s + s_sh_stage * ((group_blocks / thread_k_blocks) *
(pipe / (group_blocks / thread_k_blocks)));
reinterpret_cast<int4*>(&frag_s[k % 2])[0] = sh_s_stage[s_sh_rd];
}
int4* sh_a_stage = sh_a + a_sh_stage * pipe;
#pragma unroll
for (int i = 0; i < thread_m_blocks; i++)
ldsm4(frag_a[k % 2][i], &sh_a_stage[a_sh_rd_trans[k % b_sh_wr_iters][i]]);
int4* sh_b_stage = sh_b + b_sh_stage * pipe;
frag_b_quant[k % 2] = *reinterpret_cast<I4*>(
&sh_b_stage[b_sh_rd_delta * (k % b_sh_wr_iters) + b_sh_rd]);
};
// Execute the actual tensor core matmul of a sub-tile.
auto matmul = [&](int k) {
// We have the m dimension as the inner loop in order to encourage overlapping
// dequantization and matmul operations.
#pragma unroll
for (int j = 0; j < 4; j++) {
int b_quant = frag_b_quant[k % 2][j];
int b_quant_shift = b_quant >> 8;
FragB frag_b0 = dequant(b_quant);
// If there are no groups, we can just scale the final output once and can
// avoid doing so for each weight.
if (group_blocks != -1) scale(frag_b0, frag_s[k % 2][j], 0);
FragB frag_b1 = dequant(b_quant_shift);
if (group_blocks != -1) scale(frag_b1, frag_s[k % 2][j], 1);
#pragma unroll
for (int i = 0; i < thread_m_blocks; i++) {
mma(frag_a[k % 2][i], frag_b0, frag_c[i][j][0]);
mma(frag_a[k % 2][i], frag_b1, frag_c[i][j][1]);
}
}
};
// Since we slice across the k dimension of a tile in order to increase the
// number of warps while keeping the n dimension of a tile reasonable, we have
// multiple warps that accumulate their partial sums of the same output
// location; which we have to reduce over in the end. We do in shared memory.
auto thread_block_reduce = [&]() {
constexpr int red_off = threads / b_sh_stride / 2;
if (red_off >= 1) {
int red_idx = threadIdx.x / b_sh_stride;
constexpr int red_sh_stride = b_sh_stride * 4 * 2;
constexpr int red_sh_delta = b_sh_stride;
int red_sh_rd = red_sh_stride * (threadIdx.x / b_sh_stride) +
(threadIdx.x % b_sh_stride);
// Parallel logarithmic shared memory reduction. We make sure to avoid any
// unnecessary read or write iterations, e.g., for two warps we write only
// once by warp 1 and read only once by warp 0.
#pragma unroll
for (int m_block = 0; m_block < thread_m_blocks; m_block++) {
#pragma unroll
for (int i = red_off; i > 0; i /= 2) {
if (i <= red_idx && red_idx < 2 * i) {
#pragma unroll
for (int j = 0; j < 4 * 2; j++) {
int red_sh_wr =
red_sh_delta * j + (red_sh_rd - red_sh_stride * i);
if (i < red_off) {
float* c_rd =
reinterpret_cast<float*>(&sh[red_sh_delta * j + red_sh_rd]);
float* c_wr = reinterpret_cast<float*>(&sh[red_sh_wr]);
#pragma unroll
for (int k = 0; k < 4; k++)
reinterpret_cast<FragC*>(frag_c)[4 * 2 * m_block + j][k] +=
c_rd[k] + c_wr[k];
}
sh[red_sh_wr] =
reinterpret_cast<int4*>(&frag_c)[4 * 2 * m_block + j];
}
}
__syncthreads();
}
if (red_idx == 0) {
#pragma unroll
for (int i = 0; i < 4 * 2; i++) {
float* c_rd =
reinterpret_cast<float*>(&sh[red_sh_delta * i + red_sh_rd]);
#pragma unroll
for (int j = 0; j < 4; j++)
reinterpret_cast<FragC*>(frag_c)[4 * 2 * m_block + i][j] +=
c_rd[j];
}
}
__syncthreads();
}
}
};
// Since multiple threadblocks may process parts of the same column slice, we
// finally have to globally reduce over the results. As the striped
// partitioning minimizes the number of such reductions and our outputs are
// usually rather small, we perform this reduction serially in L2 cache.
auto global_reduce = [&](bool first = false, bool last = false) {
// We are very careful here to reduce directly in the output buffer to
// maximize L2 cache utilization in this step. To do this, we write out
// results in FP16 (but still reduce with FP32 compute).
constexpr int active_threads = 32 * thread_n_blocks / 4;
if (threadIdx.x < active_threads) {
int c_gl_stride = prob_n / 8;
int c_gl_wr_delta_o = 8 * c_gl_stride;
int c_gl_wr_delta_i = 4 * (active_threads / 32);
int c_gl_wr = c_gl_stride * ((threadIdx.x % 32) / 4) +
4 * (threadIdx.x / 32) + threadIdx.x % 4;
c_gl_wr += (2 * thread_n_blocks) * slice_col;
constexpr int c_sh_wr_delta = active_threads;
int c_sh_wr = threadIdx.x;
int row = (threadIdx.x % 32) / 4;
if (!first) {
// Interestingly, doing direct global accesses here really seems to mess up
// the compiler and lead to slowdowns, hence we also use async-copies even
// though these fetches are not actually asynchronous.
#pragma unroll
for (int i = 0; i < thread_m_blocks * 4; i++) {
cp_async4_pred(
&sh[c_sh_wr + c_sh_wr_delta * i],
&C[c_gl_wr + c_gl_wr_delta_o * (i / 2) +
c_gl_wr_delta_i * (i % 2)],
i < (thread_m_blocks - 1) * 4 || 8 * (i / 2) + row < prob_m);
}
cp_async_fence();
cp_async_wait<0>();
}
#pragma unroll
for (int i = 0; i < thread_m_blocks * 4; i++) {
if (i < (thread_m_blocks - 1) * 4 || 8 * (i / 2) + row < prob_m) {
if (!first) {
int4 c_red = sh[c_sh_wr + i * c_sh_wr_delta];
#pragma unroll
for (int j = 0; j < 2 * 4; j++) {
reinterpret_cast<float*>(
&frag_c)[4 * 2 * 4 * (i / 4) + 4 * j + (i % 4)] +=
__half2float(reinterpret_cast<__half*>(&c_red)[j]);
}
}
if (!last) {
int4 c;
#pragma unroll
for (int j = 0; j < 2 * 4; j++) {
reinterpret_cast<__half*>(&c)[j] =
__float2half(reinterpret_cast<float*>(
&frag_c)[4 * 2 * 4 * (i / 4) + 4 * j + (i % 4)]);
}
C[c_gl_wr + c_gl_wr_delta_o * (i / 2) + c_gl_wr_delta_i * (i % 2)] =
c;
}
}
}
}
};
// Write out the reduce final result in the correct layout. We only actually
// reshuffle matrix fragments in this step, the reduction above is performed
// in fragment layout.
auto write_result = [&]() {
int c_gl_stride = prob_n / 8;
constexpr int c_sh_stride = 2 * thread_n_blocks + 1;
int c_gl_wr_delta = c_gl_stride * (threads / (2 * thread_n_blocks));
constexpr int c_sh_rd_delta =
c_sh_stride * (threads / (2 * thread_n_blocks));
int c_gl_wr = c_gl_stride * (threadIdx.x / (2 * thread_n_blocks)) +
(threadIdx.x % (2 * thread_n_blocks));
c_gl_wr += (2 * thread_n_blocks) * slice_col;
int c_sh_wr =
(4 * c_sh_stride) * ((threadIdx.x % 32) / 4) + (threadIdx.x % 32) % 4;
c_sh_wr += 32 * (threadIdx.x / 32);
int c_sh_rd = c_sh_stride * (threadIdx.x / (2 * thread_n_blocks)) +
(threadIdx.x % (2 * thread_n_blocks));
int c_gl_wr_end = c_gl_stride * prob_m;
// We first reorder in shared memory to guarantee the most efficient final
// global write patterns
auto write = [&](int idx, float c0, float c1, FragS& s) {
half2 res = __halves2half2(__float2half(c0), __float2half(c1));
if (group_blocks ==
-1) // for per-column quantization we finally apply the scale here
res = __hmul2(res, s[0]);
((half2*)sh)[idx] = res;
};
if (threadIdx.x / 32 < thread_n_blocks / 4) {
#pragma unroll
for (int i = 0; i < thread_m_blocks; i++) {
#pragma unroll
for (int j = 0; j < 4; j++) {
int wr = c_sh_wr + 8 * j;
write(wr + (4 * c_sh_stride) * 0 + 0, frag_c[i][j][0][0],
frag_c[i][j][0][1], frag_s[j / 2][2 * (j % 2) + 0]);
write(wr + (4 * c_sh_stride) * 8 + 0, frag_c[i][j][0][2],
frag_c[i][j][0][3], frag_s[j / 2][2 * (j % 2) + 0]);
write(wr + (4 * c_sh_stride) * 0 + 4, frag_c[i][j][1][0],
frag_c[i][j][1][1], frag_s[j / 2][2 * (j % 2) + 1]);
write(wr + (4 * c_sh_stride) * 8 + 4, frag_c[i][j][1][2],
frag_c[i][j][1][3], frag_s[j / 2][2 * (j % 2) + 1]);
}
c_sh_wr += 16 * (4 * c_sh_stride);
}
}
__syncthreads();
#pragma unroll
for (int i = 0;
i < ceildiv(16 * thread_m_blocks, threads / (2 * thread_n_blocks));
i++) {
if (c_gl_wr < c_gl_wr_end) {
C[c_gl_wr] = sh[c_sh_rd];
c_gl_wr += c_gl_wr_delta;
c_sh_rd += c_sh_rd_delta;
}
}
};
// Start global fetch and register load pipelines.
auto start_pipes = [&]() {
#pragma unroll
for (int i = 0; i < stages - 1; i++) fetch_to_shared(i, i, i < slice_iters);
zero_accums();
wait_for_stage();
fetch_to_registers(0, 0);
a_gl_rd += a_gl_rd_delta_o * (stages - 1);
};
start_pipes();
// Main loop.
while (slice_iters) {
// We unroll over both the global fetch and the register load pipeline to
// ensure all shared memory accesses are static. Note that both pipelines have
// even length meaning that the next iteration will always start at index 0.
#pragma unroll
for (int pipe = 0; pipe < stages;) {
#pragma unroll
for (int k = 0; k < b_sh_wr_iters; k++) {
fetch_to_registers(k + 1, pipe % stages);
if (k == b_sh_wr_iters - 2) {
fetch_to_shared((pipe + stages - 1) % stages, pipe,
slice_iters >= stages);
pipe++;
wait_for_stage();
}
matmul(k);
}
slice_iters--;
if (slice_iters == 0) break;
}
a_gl_rd += a_gl_rd_delta_o * stages;
// Process results and, if necessary, proceed to the next column slice.
// While this pattern may not be the most readable, other ways of writing
// the loop seemed to noticeably worse performance after compilation.
if (slice_iters == 0) {
cp_async_wait<0>();
bool last = slice_idx == slice_count - 1;
// For per-column scales, we only fetch them here in the final step before
// write-out
if (group_blocks == -1 && last) {
if (s_sh_wr_pred) cp_async4(&sh_s[s_sh_wr], &s[s_gl_rd]);
cp_async_fence();
}
thread_block_reduce();
if (group_blocks == -1 && last) {
cp_async_wait<0>();
__syncthreads();
if (threadIdx.x / 32 < thread_n_blocks / 4) {
reinterpret_cast<int4*>(&frag_s)[0] = sh_s[s_sh_rd + 0];
reinterpret_cast<int4*>(&frag_s)[1] = sh_s[s_sh_rd + 4];
}
}
if (slice_count > 1) { // only globally reduce if there is more than one
// block in a slice
barrier_acquire(&locks[slice_col], slice_idx);
global_reduce(slice_idx == 0, last);
barrier_release(&locks[slice_col], last);
}
if (last) // only the last block in a slice actually writes the result
write_result();
slice_row = 0;
slice_col_par++;
slice_col++;
init_slice();
if (slice_iters) {
a_gl_rd = a_gl_stride * (threadIdx.x / a_gl_rd_delta_o) +
(threadIdx.x % a_gl_rd_delta_o);
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++)
B_ptr[i] += b_sh_stride - b_gl_rd_delta_o * k_tiles;
if (slice_col == 0) {
#pragma unroll
for (int i = 0; i < b_sh_wr_iters; i++) B_ptr[i] -= b_gl_stride;
}
s_gl_rd = s_sh_stride * slice_col + threadIdx.x;
start_pipes();
}
}
}
}
#else
template <const int threads, // number of threads in a threadblock
const int thread_m_blocks, // number of 16x16 blocks in the m
// dimension (batchsize) of the
// threadblock
const int thread_n_blocks, // same for n dimension (output)
const int thread_k_blocks, // same for k dimension (reduction)
const int stages, // number of stages for the async global->shared
// fetch pipeline
const int group_blocks = -1 // number of consecutive 16x16 blocks
// with a separate quantization scale
>
__global__ void Marlin(
const int4* __restrict__ A, // fp16 input matrix of shape mxk
const int4* __restrict__ B, // 4bit quantized weight matrix of shape kxn
int4* __restrict__ C, // fp16 output buffer of shape mxn
const int4* __restrict__ s, // fp16 quantization scales of shape
// (k/groupsize)xn
int prob_m, // batch dimension m
int prob_n, // output dimension n
int prob_k, // reduction dimension k
int* locks // extra global storage for barrier synchronization
) {
// Marlin is not implemented yet for SM < 8.0
assert(false);
return;
}
#endif
// 8 warps are a good choice since every SM has 4 schedulers and having more
// than 1 warp per schedule allows some more latency hiding. At the same time,
// we want relatively few warps to have many registers per warp and small tiles.
const int USER_THREADS =
256; // Note: This is only used with user-provided thread_k/n
const int STAGES = 4; // 4 pipeline stages fit into shared memory
const int SHARED_MEM =
96 * 1024; // max shared memory on compute capability 8.6 (< 8.0)
static constexpr int min_thread_n = 64;
static constexpr int min_thread_k = 64;
static constexpr int tile_size = 16;
static constexpr int max_par = 16;
static constexpr int pack_factor_4bit =
8; // We have 8 4-bit vals inside a 32 bit
#define __CALL_IF(THREAD_M_BLOCKS, THREAD_N_BLOCKS, THREAD_K_BLOCKS, \
GROUP_BLOCKS, NUM_THREADS) \
else if (thread_m_blocks == THREAD_M_BLOCKS && \
thread_n_blocks == THREAD_N_BLOCKS && \
thread_k_blocks == THREAD_K_BLOCKS && \
group_blocks == GROUP_BLOCKS && num_threads == NUM_THREADS) { \
cudaFuncSetAttribute(Marlin<NUM_THREADS, THREAD_M_BLOCKS, THREAD_N_BLOCKS, \
THREAD_K_BLOCKS, STAGES, GROUP_BLOCKS>, \
cudaFuncAttributeMaxDynamicSharedMemorySize, \
SHARED_MEM); \
Marlin<NUM_THREADS, THREAD_M_BLOCKS, THREAD_N_BLOCKS, THREAD_K_BLOCKS, \
STAGES, GROUP_BLOCKS><<<blocks, NUM_THREADS, SHARED_MEM, stream>>>( \
A_ptr, B_ptr, C_ptr, s_ptr, prob_m, prob_n, prob_k, locks); \
}
typedef struct {
int thread_k;
int thread_n;
int num_threads;
} thread_config_t;
thread_config_t small_batch_thread_configs[] = {
// Ordered by priority
// thread_k, thread_n, num_threads
{128, 128, 256}, // Default
{128, 64, 128}, // Reduce N 2X, same K
{64, 256, 256}, // Reduce K 2X, increase N 2X
{64, 128, 128}, // Reduce K 2X, same N
};
thread_config_t large_batch_thread_configs[] = {
// Ordered by priority
// thread_k, thread_n, num_threads
{64, 256, 256}, // Default
{128, 128, 256}, // Reduce N 2X, increase K 2X
{64, 128, 128}, // Reduce N 2X, same K
{128, 64, 128}, // Reduce N 4X, increase K 2X
};
bool is_valid_config(thread_config_t const& th_config, int prob_m, int prob_n,
int prob_k) {
// Sanity
if (th_config.thread_k == -1 || th_config.thread_n == -1 ||
th_config.num_threads == -1) {
return false;
}
// Verify K/N are divisible by thread K/N
if (prob_k % th_config.thread_k != 0 || prob_n % th_config.thread_n != 0) {
return false;
}
// thread_k can be only 128 or 64 (because it must be less than groupsize
// which is 128)
if (th_config.thread_k != 128 && th_config.thread_k != 64) {
return false;
}
// Verify min for thread K/N
if (th_config.thread_n < min_thread_n || th_config.thread_k < min_thread_k) {
return false;
}
// num_threads must be at least 128 (= 4 warps)
if (th_config.num_threads < 128) {
return false;
}
return true;
}
thread_config_t determine_thread_config(int prob_m, int prob_n, int prob_k) {
if (prob_m <= 16) {
for (auto th_config : small_batch_thread_configs) {
if (is_valid_config(th_config, prob_m, prob_n, prob_k)) {
return th_config;
}
}
} else {
for (auto th_config : large_batch_thread_configs) {
if (is_valid_config(th_config, prob_m, prob_n, prob_k)) {
return th_config;
}
}
}
return thread_config_t{-1, -1, -1};
}
#define CALL_IF(N_BLOCKS, K_BLOCKS, NUM_THREADS) \
__CALL_IF(1, N_BLOCKS, K_BLOCKS, -1, NUM_THREADS) \
__CALL_IF(1, N_BLOCKS, K_BLOCKS, 8, NUM_THREADS) \
__CALL_IF(1, N_BLOCKS, K_BLOCKS, -1, NUM_THREADS) \
__CALL_IF(1, N_BLOCKS, K_BLOCKS, 8, NUM_THREADS) \
__CALL_IF(2, N_BLOCKS, K_BLOCKS, -1, NUM_THREADS) \
__CALL_IF(2, N_BLOCKS, K_BLOCKS, 8, NUM_THREADS) \
__CALL_IF(3, N_BLOCKS, K_BLOCKS, -1, NUM_THREADS) \
__CALL_IF(3, N_BLOCKS, K_BLOCKS, 8, NUM_THREADS) \
__CALL_IF(4, N_BLOCKS, K_BLOCKS, -1, NUM_THREADS) \
__CALL_IF(4, N_BLOCKS, K_BLOCKS, 8, NUM_THREADS)
void marlin_cuda(const void* A, const void* B, void* C, void* s, int prob_m,
int prob_n, int prob_k, void* workspace, int groupsize = -1,
int dev = 0, cudaStream_t stream = 0, int thread_k = -1,
int thread_n = -1, int sms = -1, int max_par = 16) {
int tot_m = prob_m;
int tot_m_blocks = ceildiv(tot_m, 16);
int pad = 16 * tot_m_blocks - tot_m;
if (sms == -1)
cudaDeviceGetAttribute(&sms, cudaDevAttrMultiProcessorCount, dev);
// Set thread config
thread_config_t th_config;
if (thread_k != -1 && thread_n != -1) {
// User-defined config
th_config = thread_config_t{thread_k, thread_n, USER_THREADS};
} else {
// Auto config
th_config = determine_thread_config(prob_m, prob_n, prob_k);
}
if (!is_valid_config(th_config, prob_m, prob_n, prob_k)) {
throw std::runtime_error(
"Invalid thread config: thread_k = " + str(th_config.thread_k) +
", thread_n = " + str(th_config.thread_n) +
", num_threads = " + str(th_config.num_threads) + " for MKN = [" +
str(prob_m) + ", " + str(prob_k) + ", " + str(prob_n) + "]");
}
// Uncomment for debug
// std::cout << "Using thread_config: thread_k = " + str(th_config.thread_k) +
// ", thread_n = " + str(th_config.thread_n) +
// ", num_threads = " + str(th_config.num_threads) + " for
// MKN = [" + str(prob_m) +
// ", " + str(prob_k) + ", " + str(prob_n) + "]\n";
int num_threads = th_config.num_threads;
thread_k = th_config.thread_k;
thread_n = th_config.thread_n;
int thread_k_blocks = thread_k / 16;
int thread_n_blocks = thread_n / 16;
int group_blocks = (groupsize == -1) ? -1 : groupsize / 16;
int blocks = sms;
if (prob_m == 0 || prob_n == 0 || prob_k == 0) {
return;
}
TORCH_CHECK(prob_n % thread_n == 0, "prob_n = ", prob_n,
" is not divisible by thread_n = ", thread_n);
TORCH_CHECK(prob_k % thread_k == 0, "prob_k = ", prob_k,
" is not divisible by thread_k = ", thread_k);
if (group_blocks != -1) {
TORCH_CHECK(prob_k % group_blocks == 0, "prob_k = ", prob_k,
" is not divisible by group_blocks = ", group_blocks);
}
const int4* A_ptr = (const int4*)A;
const int4* B_ptr = (const int4*)B;
int4* C_ptr = (int4*)C;
const int4* s_ptr = (const int4*)s;
int* locks = (int*)workspace;
for (int i = 0; i < tot_m_blocks; i += 4) {
int thread_m_blocks = tot_m_blocks - i;
prob_m = tot_m - 16 * i;
int par = 1;
if (thread_m_blocks > 4) {
// Note that parallel > 1 currently only works for inputs without any
// padding
par = (16 * thread_m_blocks - pad) / 64;
if (par > max_par) par = max_par;
prob_m = 64 * par;
i += 4 * (par - 1);
thread_m_blocks = 4;
}
// For compilation speed, we only define the kernel configurations that have
// seemed useful (in terms of performance) in our testing, however many more
// are, in principle, possible.
if (false) {
}
CALL_IF(8, 8, 256)
CALL_IF(16, 4, 256)
CALL_IF(8, 4, 128)
CALL_IF(4, 8, 128)
else {
throw std::runtime_error("Unsupported shapes: MKN = [" + str(prob_m) +
", " + str(prob_k) + ", " + str(prob_n) + "]" +
", groupsize = " + str(groupsize) +
", thread_m_blocks = " + str(thread_m_blocks) +
", thread_n_blocks = " + str(thread_n_blocks) +
", thread_k_blocks = " + str(thread_k_blocks));
}
A_ptr += 16 * thread_m_blocks * (prob_k / 8) * par;
C_ptr += 16 * thread_m_blocks * (prob_n / 8) * par;
}
}
} // namespace marlin
torch::Tensor marlin_gemm(torch::Tensor& a, torch::Tensor& b_q_weight,
torch::Tensor& b_scales, torch::Tensor& workspace,
int64_t size_m, int64_t size_n, int64_t size_k) {
// Verify M
TORCH_CHECK(size_m == a.size(0),
"Shape mismatch: a.size(0) = " + str(a.size(0)) +
", size_m = " + str(size_m));
// Verify K
TORCH_CHECK(size_k == a.size(1),
"Shape mismatch: a.size(1) = " + str(a.size(1)) +
", size_k = " + str(size_k));
TORCH_CHECK(size_k % marlin::tile_size == 0,
"size_k = " + str(size_k) +
" is not divisible by tile_size = " + str(marlin::tile_size));
TORCH_CHECK((size_k / marlin::tile_size) == b_q_weight.size(0),
"Shape mismatch: b_q_weight.size(0) = " +
str(b_q_weight.size(0)) + ", size_k = " + str(size_k) +
", tile_size = " + str(marlin::tile_size));
// Verify N
TORCH_CHECK(b_scales.size(1) == size_n,
"b_scales.size(1) = " + str(b_scales.size(1)) +
", size_n = " + str(size_n));
TORCH_CHECK(b_q_weight.size(1) % marlin::tile_size == 0,
"b_q_weight.size(1) = " + str(b_q_weight.size(1)) +
" is not divisible by tile_size = " + str(marlin::tile_size));
int actual_size_n =
(b_q_weight.size(1) / marlin::tile_size) * marlin::pack_factor_4bit;
TORCH_CHECK(
size_n == actual_size_n,
"size_n = " + str(size_n) + ", actual_size_n = " + str(actual_size_n));
// Verify A device and strides
TORCH_CHECK(a.device().is_cuda(), "A is not on GPU");
TORCH_CHECK(a.is_contiguous(), "A is not contiguous");
// Verify B device and strides
TORCH_CHECK(b_q_weight.device().is_cuda(), "b_q_weight is not on GPU");
TORCH_CHECK(b_q_weight.is_contiguous(), "b_q_weight is not contiguous");
// Verify scales device and strides
TORCH_CHECK(b_scales.device().is_cuda(), "b_scales is not on GPU");
TORCH_CHECK(b_scales.is_contiguous(), "b_scales is not contiguous");
// Alloc C matrix
const at::cuda::OptionalCUDAGuard device_guard(device_of(a));
auto options = torch::TensorOptions().dtype(a.dtype()).device(a.device());
torch::Tensor c = torch::empty({size_m, size_n}, options);
// thread_k: `k` size of a thread_tile in `weights` (can usually be left as
// auto -1)
int thread_k = -1;
// thread_n: `n` size of a thread_tile in `weights` (can usually be left as
// auto -1)
int thread_n = -1;
// sms: number of SMs to use for the kernel (can usually be left as auto -1)
int sms = -1;
// Detect groupsize
if (b_scales.size(0) != 1) {
TORCH_CHECK(size_k % b_scales.size(0) == 0,
"size_k = " + str(size_k) +
", is not divisible by b_scales.size(0) = " +
str(b_scales.size(0)));
}
int groupsize = b_scales.size(0) == 1 ? -1 : size_k / b_scales.size(0);
// Verify groupsize
TORCH_CHECK(groupsize == -1 || groupsize == 128,
"Unexpected groupsize = " + str(groupsize));
// Verify workspace size
TORCH_CHECK(
size_n % marlin::min_thread_n == 0,
"size_n = " + str(size_n) +
", is not divisible by min_thread_n = " + str(marlin::min_thread_n));
int min_workspace_size = (size_n / marlin::min_thread_n) * marlin::max_par;
TORCH_CHECK(workspace.numel() >= min_workspace_size,
"workspace.numel = " + str(workspace.numel()) +
" is below min_workspace_size = " + str(min_workspace_size));
int dev = a.get_device();
marlin::marlin_cuda(a.data_ptr(), b_q_weight.data_ptr(), c.data_ptr(),
b_scales.data_ptr(), size_m, size_n, size_k,
workspace.data_ptr(), groupsize, dev,
at::cuda::getCurrentCUDAStream(dev), thread_k, thread_n,
sms, marlin::max_par);
return c;
}
server/marlin/setup.py 0 → 100644
View file @ 093a27c5
from setuptools import setup
from torch.utils.cpp_extension import BuildExtension, CUDAExtension
extra_compile_args = []
setup(
name="marlin_kernels",
ext_modules=[
CUDAExtension(
name="marlin_kernels",
sources=[
"marlin_kernels/gptq_marlin.cu",
"marlin_kernels/gptq_marlin_repack.cu",
"marlin_kernels/marlin_cuda_kernel.cu",
"marlin_kernels/ext.cpp",
],
extra_compile_args=extra_compile_args,
),
],
cmdclass={"build_ext": BuildExtension},
)
server/text_generation_server/layers/linear.py
View file @ 093a27c5
from typing import Optional
import torch
from torch.nn import functional as F
from text_generation_server.layers.marlin import GPTQMarlinLinear
from text_generation_server.utils.import_utils import SYSTEM
if SYSTEM == "rocm":
......@@ -223,13 +224,23 @@ def get_linear(weight, bias, quantize):
"You do not seem to have awq installed, either install it (cd server && make install-awq), or try using GPTQ `---quantize gptq` a conversion AWQ->GPTQ will happen on the fly"
)
elif quantize == "marlin":
from text_generation_server.layers.marlin import MarlinLinear, MarlinWeight
from text_generation_server.layers.marlin import (
GPTQMarlinWeight,
MarlinLinear,
MarlinWeight,
)
if not isinstance(weight, MarlinWeight):
if isinstance(weight, GPTQMarlinWeight):
linear = GPTQMarlinLinear(
weight=weight,
bias=bias,
)
elif isinstance(weight, MarlinWeight):
linear = MarlinLinear(weight=weight, bias=bias)
else:
raise NotImplementedError(
f"The passed weight is not `marlin` compatible, loader needs to be updated."
)
linear = MarlinLinear(B=weight.B, s=weight.s, bias=bias)
else:
raise NotImplementedError(f"Quantization `{quantize}` is not implemented yet.")
return linear
server/text_generation_server/layers/marlin.py
View file @ 093a27c5
from dataclasses import dataclass
from typing import Optional
from typing import Optional, Tuple, List
import torch
import torch.nn as nn
from text_generation_server.utils.import_utils import SYSTEM
try:
import marlin
import marlin_kernels
except ImportError:
marlin = None
marlin_kernels = None
try:
major, _minor = torch.cuda.get_device_capability()
......@@ -15,9 +17,204 @@ try:
except Exception:
has_sm_8_0 = False
GPTQ_MARLIN_BITS = [4, 8]
GPTQ_MARLIN_GROUP_SIZES = [-1, 32, 64, 128]
MARLIN_TILE_SIZE = 16
def _check_marlin_kernels():
if not (SYSTEM == "cuda" and has_sm_8_0):
raise NotImplementedError(
"Using quantized Marlin models requires a GPU with CUDA capability 8.0 or later."
)
if marlin_kernels is None:
raise NotImplementedError(
"marlin is not installed, install it with: pip install server/marlin"
)
def _check_valid_shape(in_features: int, out_features: int):
if (in_features % 128 != 0 or out_features % 64 != 0) and (
in_features % 64 != 0 or out_features % 128 != 0
):
raise ValueError(
f"The GPTQ Marlin kernel does not have a valid thread configuration for weight matrix with shape ({out_features}, {in_features})."
" The shape elements must be divisible by (128, 64) or (64, 128)."
)
# https://github.com/IST-DASLab/marlin/blob/2f6d7c10e124b3c5fa29ff8d77d568bd7af3274c/marlin/__init__.py#L40C1-L68C54
def _get_perms() -> Tuple[List[int], List[int]]:
scale_perm = []
for i in range(8):
scale_perm.extend([i + 8 * j for j in range(8)])
scale_perm_single = []
for i in range(4):
scale_perm_single.extend([2 * i + j for j in [0, 1, 8, 9, 16, 17, 24, 25]])
return scale_perm, scale_perm_single
_scale_perm, _scale_perm_single = _get_perms()
def permute_scales(scales: torch.Tensor):
out_features = scales.shape[1]
if scales.shape[0] == 1:
scales = scales.reshape((-1, len(_scale_perm_single)))[:, _scale_perm_single]
else:
scales = scales.reshape((-1, len(_scale_perm)))[:, _scale_perm]
return scales.reshape((-1, out_features)).contiguous()
@dataclass
class GPTQMarlinWeight:
"""
Repacked GPTQ Marlin weights.
"""
qweight: torch.Tensor
scales: torch.Tensor
g_idx: torch.Tensor
perm: torch.Tensor
bits: int
is_full_k: bool
def __post_init__(self):
assert self.qweight.dtype == torch.int32
assert self.scales.dtype == torch.float16
assert self.g_idx.dtype == torch.int32
assert self.perm.dtype == torch.int32
def repack_gptq_for_marlin(
*,
qweight: torch.Tensor,
scales: torch.Tensor,
g_idx: torch.Tensor,
bits: int,
desc_act: bool,
groupsize: int,
sym: bool,
sharded_infeatures: bool,
) -> GPTQMarlinWeight:
"""Convert GPTQ weights to a layout that's compatible with GPTQ-Marlin kernels."""
_check_marlin_kernels()
assert marlin_kernels is not None
if bits not in GPTQ_MARLIN_BITS:
supported_bits = ", ".join(str(b) for b in GPTQ_MARLIN_BITS)
raise RuntimeError(
f"Repacking {bits}-bit GPTQ weights as Marlin is not supported, must be one of: {supported_bits}"
)
if groupsize not in GPTQ_MARLIN_GROUP_SIZES:
supported_sizes = ", ".join(str(b) for b in GPTQ_MARLIN_GROUP_SIZES)
raise RuntimeError(
f"Repacking GPTQ weights with group size {groupsize} as Marlin is not supported, must be one of: {supported_sizes}"
)
if not sym:
raise RuntimeError(
"Repacking GPTQ weights with asymmetric quantization as Marlin is not supported."
)
weights_per_int = 32 // bits
in_features = qweight.shape[0] * weights_per_int
out_features = qweight.shape[1]
if in_features % groupsize != 0:
raise ValueError(
f"Number of input features ({in_features}) not divisible by group size ({groupsize})"
)
if desc_act and groupsize != -1:
perm = torch.argsort(g_idx).to(torch.int)
g_idx = g_idx[perm]
else:
perm = torch.empty(0, dtype=torch.int, device=qweight.device)
g_idx = torch.empty(0, dtype=torch.int, device=qweight.device)
repacked = marlin_kernels.gptq_marlin_repack(
qweight, perm, in_features, out_features, bits
)
scales = permute_scales(scales)
is_full_k = not (desc_act and sharded_infeatures)
return GPTQMarlinWeight(
qweight=repacked,
scales=scales,
g_idx=g_idx,
perm=perm,
bits=bits,
is_full_k=is_full_k,
)
class GPTQMarlinLinear(nn.Module):
"""
Linear layer for GPTQ weights that were converted for the GPTQ-Marlin
kernels.
"""
def __init__(
self,
*,
weight: GPTQMarlinWeight,
bias: Optional[torch.Tensor],
):
super().__init__()
_check_marlin_kernels()
assert marlin_kernels is not None
in_features = weight.qweight.shape[0] * MARLIN_TILE_SIZE
out_features = weight.scales.shape[1]
_check_valid_shape(in_features=in_features, out_features=out_features)
self.bits = weight.bits
self.is_full_k = weight.is_full_k
self.register_buffer("qweight", weight.qweight)
self.register_buffer("scales", weight.scales)
self.register_buffer("g_idx", weight.g_idx)
self.register_buffer("perm", weight.perm)
if bias is not None:
self.register_buffer("bias", bias)
else:
self.bias = None
self.workspace = torch.zeros(
out_features // 64 * 16, dtype=torch.int, device=weight.qweight.device
)
def forward(self, A: torch.Tensor) -> torch.Tensor:
assert marlin_kernels is not None
A_flat = A.view(-1, A.shape[-1])
C = marlin_kernels.gptq_marlin_gemm(
A_flat,
self.qweight,
self.scales,
self.g_idx,
self.perm,
self.workspace,
self.bits,
A_flat.shape[0],
self.scales.shape[1],
A_flat.shape[1],
self.is_full_k,
)
C = C.reshape(A.shape[:-1] + (self.scales.shape[1],))
if self.bias is not None:
C += self.bias
return C
@dataclass
class MarlinWeight:
"""
......@@ -31,28 +228,20 @@ class MarlinWeight:
B: torch.Tensor
s: torch.Tensor
def __post_init__(self):
assert self.B.dtype == torch.int32
assert self.s.dtype == torch.float16
class MarlinLinear(nn.Module):
def __init__(
self, *, B: torch.Tensor, s: torch.Tensor, bias: Optional[torch.Tensor]
):
def __init__(self, *, weight: MarlinWeight, bias: Optional[torch.Tensor]):
super().__init__()
if not has_sm_8_0:
raise NotImplementedError(
"Using quantized marlin models requires CUDA capability 8.0 or later"
)
_check_marlin_kernels()
assert marlin_kernels is not None
if marlin is None:
raise NotImplementedError(
"You do not seem to have marlin installed, either install it (cd server && make install-marlin)"
)
assert B.dtype == torch.int32
assert s.dtype == torch.float16
in_features = B.shape[0] * MARLIN_TILE_SIZE
out_features = s.shape[1]
in_features = weight.B.shape[0] * MARLIN_TILE_SIZE
out_features = weight.s.shape[1]
assert (
in_features % 128 == 0
), f"Number of input features ({in_features}) not divisable by 128"
......@@ -60,35 +249,36 @@ class MarlinLinear(nn.Module):
out_features % 256 == 0
), f"Number of output features ({out_features}) not divisable by 256"
group_size = -1 if s.shape[0] == 1 else in_features // s.shape[0]
assert group_size in {
groupsize = -1 if weight.s.shape[0] == 1 else in_features // weight.s.shape[0]
assert groupsize in {
-1,
128,
}, f"Group size must be -1 or 128, was {group_size}"
}, f"Group size must be -1 or 128, was {groupsize}"
self.register_buffer("B", B)
self.register_buffer("s", s)
self.register_buffer("B", weight.B)
self.register_buffer("s", weight.s)
if bias is not None:
self.register_buffer("bias", bias)
else:
self.bias = None
self.workspace = torch.zeros(
out_features // 128 * 16, dtype=torch.int, device=B.device
out_features // 64 * 16, dtype=torch.int, device=weight.B.device
)
def forward(self, A: torch.Tensor) -> torch.Tensor:
assert marlin is not None
C = torch.empty(
A.shape[:-1] + (self.s.shape[1],), dtype=A.dtype, device=A.device
)
marlin.mul(
A.view((-1, A.shape[-1])),
assert marlin_kernels is not None
C = marlin_kernels.marlin_gemm(
A.view(-1, A.shape[-1]),
self.B,
C.view((-1, C.shape[-1])),
self.s,
self.workspace,
A.shape[0],
self.s.shape[1],
A.shape[1],
)
C = C.reshape(A.shape[:-1] + (self.s.shape[1],))
if self.bias is not None:
C += self.bias
......
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