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3 Commits

Author SHA1 Message Date
Angelos Katharopoulos 5ae36f2c08 Tentative JACCL examples 2026-04-22 01:29:40 -07:00
Cheng c284e0a231 Enable swap for all CI building CUDA (#3437) 2026-04-22 13:13:24 +09:00
Cheng b9b1bfb9a5 Generate qmm implementaions with cmake (#3424) 2026-04-22 13:11:55 +09:00
23 changed files with 691 additions and 264 deletions
+1 -1
View File
@@ -55,7 +55,7 @@ runs:
echo "::endgroup::"
- name: Set swap space
if: ${{ startsWith(inputs.toolkit, 'cuda') && runner.arch == 'arm64' }}
if: ${{ startsWith(inputs.toolkit, 'cuda') }}
uses: pierotofy/set-swap-space@fc79b3f67fa8a838184ce84a674ca12238d2c761
with:
swap-size-gb: 16
+33 -17
View File
@@ -1,19 +1,35 @@
target_sources(
mlx
PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/qmm.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmv.cu
${CMAKE_CURRENT_SOURCE_DIR}/fp_qmv.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_naive_m16_k.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_naive_m16_n.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_naive_m32_k.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_naive_m32_n.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_naive_m64_k.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_naive_m64_n.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_sm80_m16.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_sm80_m32.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_sm80_m64.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_sm90_m128_n16_m1.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_sm90_m128_n32_m1.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_sm90_m128_n64_m2.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_sm90_m128_n128_m2.cu
${CMAKE_CURRENT_SOURCE_DIR}/qmm_impl_sm90_m128_n256_m2.cu)
PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/qmm.cu ${CMAKE_CURRENT_SOURCE_DIR}/qmv.cu
${CMAKE_CURRENT_SOURCE_DIR}/fp_qmv.cu)
foreach(TileN 16 32 64 128 256)
set(OUTPUT_FILE "qmm_sm90_impl_n${TileN}.cu")
configure_file("${CMAKE_CURRENT_SOURCE_DIR}/qmm_sm90.cu"
"${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE}" @ONLY)
target_sources(mlx PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE})
endforeach()
foreach(TileM 16 32 64)
set(OUTPUT_FILE "qmm_sm80_impl_m${TileM}.cu")
configure_file("${CMAKE_CURRENT_SOURCE_DIR}/qmm_sm80.cu"
"${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE}" @ONLY)
target_sources(mlx PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE})
endforeach()
foreach(TileM 16 32 64)
foreach(KMajor true false)
foreach(HasKResidue true false)
foreach(SM80 true false)
if(${KMajor} AND ${HasKResidue})
continue()
endif()
set(OUTPUT_FILE
"qmm_naive_impl_m${TileM}_${KMajor}_${HasKResidue}_${SM80}.cu")
configure_file("${CMAKE_CURRENT_SOURCE_DIR}/qmm_naive.cu"
"${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE}" @ONLY)
target_sources(mlx PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE})
endforeach()
endforeach()
endforeach()
endforeach()
+47 -28
View File
@@ -17,9 +17,9 @@ inline bool is_last_2_dims_row_contiguous(const array& x) {
} // namespace
#if defined(MLX_CUDA_SM90A_ENABLED)
// Defined in qmm_impl_sm90_xxx.cu files.
template <typename TileShape, typename ClusterShape>
void qmm_impl_sm90(
// Defined in qmm_sm90.cu.
template <int TileN>
void qmm_sm90_impl(
const array& x,
const array& w,
const array& scales,
@@ -83,24 +83,21 @@ void qmm_sm90(
cu::CommandEncoder& encoder,
Stream s) {
#if defined(MLX_CUDA_SM90A_ENABLED)
auto dispatch = [&]<int tile_m, int tile_n, int cluster_m>() {
using cute::Int;
using TileShapeMN = cute::Shape<Int<tile_m>, Int<tile_n>>;
using ClusterShape = cute::Shape<Int<cluster_m>, Int<1>, Int<1>>;
qmm_impl_sm90<TileShapeMN, ClusterShape>(
auto dispatch = [&]<int TileN>() {
qmm_sm90_impl<TileN>(
x, w, scales, biases, out, bits, group_size, encoder, s);
};
int m = out.ndim() > 1 ? out.shape(-2) : 1;
if (m <= 16) {
dispatch.template operator()<128, 16, 1>();
dispatch.template operator()<16>();
} else if (m <= 32) {
dispatch.template operator()<128, 32, 1>();
dispatch.template operator()<32>();
} else if (m <= 64) {
dispatch.template operator()<128, 64, 2>();
dispatch.template operator()<64>();
} else if (m <= 128) {
dispatch.template operator()<128, 128, 2>();
dispatch.template operator()<128>();
} else {
dispatch.template operator()<128, 256, 2>();
dispatch.template operator()<256>();
}
#else
throw std::runtime_error(
@@ -108,9 +105,9 @@ void qmm_sm90(
#endif // defined(MLX_CUDA_SM90A_ENABLED)
}
// Defined in qmm_impl_sm80_xxx.cu files.
// Defined in qmm_sm80.cu.
template <int TileM>
void qmm_impl_sm80(
void qmm_sm80_impl(
const array& x,
const array& w,
const array& scales,
@@ -174,7 +171,7 @@ void qmm_sm80(
QuantizationMode mode,
cu::CommandEncoder& encoder) {
auto dispatch = [&]<int TileM>() {
qmm_impl_sm80<TileM>(
qmm_sm80_impl<TileM>(
x,
w,
scales,
@@ -197,9 +194,9 @@ void qmm_sm80(
}
}
// Defined in qmm_impl_naive_xxx.cu files.
template <int TileM, bool KMajor>
void qmm_impl_naive(
// Defined in qmm_naive.cu.
template <int TileM, bool KMajor, bool HasKResidue, bool SM80>
void qmm_naive_impl(
const array& x,
const array& w,
const array& scales,
@@ -250,8 +247,8 @@ void qmm_naive(
int group_size,
QuantizationMode mode,
cu::CommandEncoder& encoder) {
auto dispatch = [&]<int TileM, bool KMajor>() {
qmm_impl_naive<TileM, KMajor>(
auto dispatch = [&]<int TileM, bool KMajor, bool HasKResidue, bool SM80>() {
qmm_naive_impl<TileM, KMajor, HasKResidue, SM80>(
x,
w,
scales,
@@ -264,15 +261,37 @@ void qmm_naive(
mode,
encoder);
};
dispatch_bool(transpose, [&](auto k_major) {
int m = out.ndim() > 1 ? out.shape(-2) : 1;
if (m <= 16) {
dispatch.template operator()<16, k_major.value>();
} else if (m <= 32) {
dispatch.template operator()<32, k_major.value>();
auto dispatch_k = [&](auto k_major, bool has_k_residue, auto&& f) {
if constexpr (k_major.value) {
if (has_k_residue) {
throw std::invalid_argument(
"[quantized_matmul] K must be multiples of group_size.");
}
f.template operator()<false>();
} else {
dispatch.template operator()<64, k_major.value>();
dispatch_bool(has_k_residue, [&](auto has_k_residue) {
f.template operator()<has_k_residue.value>();
});
}
};
int m = out.ndim() > 1 ? out.shape(-2) : 1;
int k = x.shape(-1);
bool has_k_residue = k % group_size != 0;
bool sm80 = encoder.device().compute_capability_major() >= 8;
dispatch_bool(transpose, [&](auto k_major) {
dispatch_k(k_major, has_k_residue, [&]<bool HasKResidue>() {
dispatch_bool(sm80, [&](auto sm80) {
constexpr bool KMajor = k_major.value;
constexpr bool SM80 = sm80.value;
if (m <= 16) {
dispatch.template operator()<16, KMajor, HasKResidue, SM80>();
} else if (m <= 32) {
dispatch.template operator()<32, KMajor, HasKResidue, SM80>();
} else {
dispatch.template operator()<64, KMajor, HasKResidue, SM80>();
}
});
});
});
}
@@ -1,5 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_naive.cuh"
QMM_NAIVE_GPU(16, true)
@@ -1,5 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_naive.cuh"
QMM_NAIVE_GPU(16, false)
@@ -1,5 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_naive.cuh"
QMM_NAIVE_GPU(32, true)
@@ -1,5 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_naive.cuh"
QMM_NAIVE_GPU(32, false)
@@ -1,5 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_naive.cuh"
QMM_NAIVE_GPU(64, true)
@@ -1,5 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_naive.cuh"
QMM_NAIVE_GPU(64, false)
@@ -1,5 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_sm80.cuh"
QMM_SM80_GPU(16)
@@ -1,5 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_sm80.cuh"
QMM_SM80_GPU(32)
@@ -1,5 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_sm80.cuh"
QMM_SM80_GPU(64)
@@ -1,10 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_sm90.cuh"
using namespace cute;
using TileShapeMN = Shape<_128, _128>;
using ClusterShape = Shape<_2, _1, _1>;
QMM_SM90_GPU(TileShapeMN, ClusterShape)
@@ -1,10 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_sm90.cuh"
using namespace cute;
using TileShapeMN = Shape<_128, _16>;
using ClusterShape = Shape<_1, _1, _1>;
QMM_SM90_GPU(TileShapeMN, ClusterShape)
@@ -1,10 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_sm90.cuh"
using namespace cute;
using TileShapeMN = Shape<_128, _256>;
using ClusterShape = Shape<_2, _1, _1>;
QMM_SM90_GPU(TileShapeMN, ClusterShape)
@@ -1,10 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_sm90.cuh"
using namespace cute;
using TileShapeMN = Shape<_128, _32>;
using ClusterShape = Shape<_1, _1, _1>;
QMM_SM90_GPU(TileShapeMN, ClusterShape)
@@ -1,10 +0,0 @@
// Copyright © 2026 Apple Inc.
#include "mlx/backend/cuda/quantized/qmm/qmm_impl_sm90.cuh"
using namespace cute;
using TileShapeMN = Shape<_128, _64>;
using ClusterShape = Shape<_2, _1, _1>;
QMM_SM90_GPU(TileShapeMN, ClusterShape)
@@ -316,7 +316,7 @@ inline constexpr auto make_scales_layout(auto n, auto k, auto l, auto group_size
}
}
template <int TileM = 16, bool KMajor = true, bool SM80 = true, bool HasKResidue = false,
template <int TileM = 16, bool KMajor = true, bool HasKResidue = false, bool SM80 = true,
typename Element, typename Quant, typename Scale>
void qmm_naive(
const Element* A,
@@ -396,21 +396,6 @@ void qmm_naive(
namespace mlx::core {
template <bool KMajor, typename F>
inline void dispatch_k(bool has_k_residue, const char* tag, F&& f) {
if constexpr (KMajor) {
if (has_k_residue) {
throw std::invalid_argument(
fmt::format("{} K must be multiples of group_size.", tag));
}
f.template operator()<false>();
} else {
dispatch_bool(has_k_residue, [&](auto has_k_residue) {
f.template operator()<has_k_residue.value>();
});
}
}
template <typename F>
inline void dispatch_element_types(Dtype dtype, const char* tag, F&& f) {
if (dtype == float32) {
@@ -474,8 +459,8 @@ inline void dispatch_quant_types(
}
}
template <int TileM, bool KMajor>
void qmm_impl_naive(
template <int TileM, bool KMajor, bool HasKResidue, bool SM80>
void qmm_naive_impl(
const array& x,
const array& w,
const array& scales,
@@ -494,71 +479,65 @@ void qmm_impl_naive(
int l = out.size() / (m * n);
bool broadcast_b = (w.ndim() <= 2) || (w.size() != w.data_size());
bool is_sm80 = encoder.device().compute_capability_major() >= 8;
dispatch_bool(is_sm80, [&](auto sm80) {
dispatch_k<KMajor>(k % group_size != 0, tag, [&]<bool has_k_residue>() {
dispatch_element_types(out.dtype(), tag, [&]<typename Element>() {
dispatch_quant_types<Element>(
bits,
group_size,
mode,
tag,
[&]<typename Quant, typename Scale, int group_size>() {
encoder.set_input_array(x);
encoder.set_input_array(w);
encoder.set_input_array(scales);
if (biases) {
encoder.set_input_array(*biases);
}
if (lhs_indices) {
encoder.set_input_array(*lhs_indices);
}
if (rhs_indices) {
encoder.set_input_array(*rhs_indices);
}
encoder.set_output_array(out);
cutlass_gemm::qmm_naive<TileM, KMajor, sm80.value, has_k_residue>(
gpu_ptr<Element>(x),
gpu_ptr<Quant>(w),
gpu_ptr<Scale>(scales),
biases ? gpu_ptr<Element>(*biases) : nullptr,
lhs_indices ? gpu_ptr<uint32_t>(*lhs_indices) : nullptr,
rhs_indices ? gpu_ptr<uint32_t>(*rhs_indices) : nullptr,
gpu_ptr<Element>(out),
m,
n,
k,
l,
broadcast_b,
cute::Int<group_size>{},
[&](auto* kernel,
dim3 num_blocks,
dim3 block_dims,
uint32_t smem_bytes,
void** args) {
encoder.add_kernel_node_raw(
kernel, num_blocks, block_dims, {}, smem_bytes, args);
});
});
});
});
dispatch_element_types(out.dtype(), tag, [&]<typename Element>() {
dispatch_quant_types<Element>(
bits,
group_size,
mode,
tag,
[&]<typename Quant, typename Scale, int group_size>() {
encoder.set_input_array(x);
encoder.set_input_array(w);
encoder.set_input_array(scales);
if (biases) {
encoder.set_input_array(*biases);
}
if (lhs_indices) {
encoder.set_input_array(*lhs_indices);
}
if (rhs_indices) {
encoder.set_input_array(*rhs_indices);
}
encoder.set_output_array(out);
cutlass_gemm::qmm_naive<TileM, KMajor, HasKResidue, SM80>(
gpu_ptr<Element>(x),
gpu_ptr<Quant>(w),
gpu_ptr<Scale>(scales),
biases ? gpu_ptr<Element>(*biases) : nullptr,
lhs_indices ? gpu_ptr<uint32_t>(*lhs_indices) : nullptr,
rhs_indices ? gpu_ptr<uint32_t>(*rhs_indices) : nullptr,
gpu_ptr<Element>(out),
m,
n,
k,
l,
broadcast_b,
cute::Int<group_size>{},
[&](auto* kernel,
dim3 num_blocks,
dim3 block_dims,
uint32_t smem_bytes,
void** args) {
encoder.add_kernel_node_raw(
kernel, num_blocks, block_dims, {}, smem_bytes, args);
});
});
});
}
} // namespace mlx::core
// clang-format off
template void qmm_naive_impl<@TileM@, @KMajor@, @HasKResidue@, @SM80@>(
const array& x,
const array& w,
const array& scales,
const std::optional<array>& biases,
const std::optional<array>& lhs_indices,
const std::optional<array>& rhs_indices,
array& out,
int bits,
int group_size,
QuantizationMode mode,
cu::CommandEncoder& encoder);
// clang-format on
#define QMM_NAIVE_GPU(TileM, KMajor) \
namespace mlx::core { \
template void qmm_impl_naive<TileM, KMajor>( \
const array& x, \
const array& w, \
const array& scales, \
const std::optional<array>& biases, \
const std::optional<array>& lhs_indices, \
const std::optional<array>& rhs_indices, \
array& out, \
int bits, \
int group_size, \
QuantizationMode mode, \
cu::CommandEncoder& encoder); \
}
} // namespace mlx::core
@@ -434,7 +434,7 @@ inline void dispatch_quant_types(
}
template <int TileM>
void qmm_impl_sm80(
void qmm_sm80_impl(
const array& x,
const array& w,
const array& scales,
@@ -499,20 +499,19 @@ void qmm_impl_sm80(
});
}
} // namespace mlx::core
// clang-format off
template void qmm_sm80_impl<@TileM@>(
const array& x,
const array& w,
const array& scales,
const std::optional<array>& biases,
const std::optional<array>& lhs_indices,
const std::optional<array>& rhs_indices,
array& out,
int bits,
int group_size,
QuantizationMode mode,
cu::CommandEncoder& encoder);
// clang-format on
#define QMM_SM80_GPU(TileM) \
namespace mlx::core { \
template void qmm_impl_sm80<TileM>( \
const array& x, \
const array& w, \
const array& scales, \
const std::optional<array>& biases, \
const std::optional<array>& lhs_indices, \
const std::optional<array>& rhs_indices, \
array& out, \
int bits, \
int group_size, \
QuantizationMode mode, \
cu::CommandEncoder& encoder); \
}
} // namespace mlx::core
@@ -20,8 +20,7 @@ namespace cutlass_gemm {
using namespace cute;
template <
typename TileShapeMN = Shape<_128, _16>,
typename ClusterShape = Shape<_1, _1, _1>,
int TileN = 16,
typename Element,
typename Quant,
typename GroupSize,
@@ -47,7 +46,8 @@ void qmm_sm90(
using Arch = cutlass::arch::Sm90;
using Accumulator = float;
using TileShape = decltype(append(TileShapeMN{}, Int<kTileShapeK>{}));
using TileShape = Shape<_128, Int<TileN>, Int<kTileShapeK>>;
using ClusterShape = Shape<Int<(TileN <= 32) ? 1 : 2>, _1, _1>;
using Epilogue = typename cutlass::epilogue::collective::CollectiveBuilder<
Arch,
@@ -177,8 +177,8 @@ inline void dispatch_groups(int group_size, const char* tag, F&& f) {
}
}
template <typename TileShapeMN, typename ClusterShape>
void qmm_impl_sm90(
template <int TileN>
void qmm_sm90_impl(
const array& x,
const array& w,
const array& scales_,
@@ -207,7 +207,7 @@ void qmm_impl_sm90(
encoder.set_input_array(scales);
encoder.set_input_array(biases);
encoder.set_output_array(out);
cutlass_gemm::qmm_sm90(
cutlass_gemm::qmm_sm90<TileN>(
gpu_ptr<Element>(x),
gpu_ptr<Quant>(w),
gpu_ptr<Element>(scales),
@@ -238,24 +238,19 @@ void qmm_impl_sm90(
});
}
// clang-format off
template void qmm_sm90_impl<@TileN@>(
const array& x,
const array& w,
const array& scales,
const array& biases,
array& out,
int bits,
int group_size,
cu::CommandEncoder& encoder,
Stream s);
// clang-format on
} // namespace mlx::core
#define QMM_SM90_GPU(TileShapeMN, ClusterShape) \
namespace mlx::core { \
template void qmm_impl_sm90<TileShapeMN, ClusterShape>( \
const array& x, \
const array& w, \
const array& scales, \
const array& biases, \
array& out, \
int bits, \
int group_size, \
cu::CommandEncoder& encoder, \
Stream s); \
}
#else
#define QMM_SM90_GPU(TileShapeMN, ClusterShape)
#endif // defined(MLX_CUDA_SM90A_ENABLED)
@@ -35,6 +35,8 @@ endfunction()
# Examples
build_example(minimal_env.cpp)
build_example(minimal_cfg.cpp)
build_example(monte_carlo_pi.cpp)
build_example(file_broadcast.cpp)
# Benchmarks
build_example(allreduce_bench.cpp)
@@ -0,0 +1,360 @@
// Copyright © 2025 Apple Inc.
//
// File Broadcast with JACCL
//
// This example demonstrates distributed file transfer using JACCL's all_sum
// operation to broadcast a file from any rank to all other machines.
//
// The algorithm:
// 1. The sender rank reads the file into memory
// 2. All other ranks allocate zero-filled buffers of the same size
// 3. Use all_sum to broadcast: sender has data, others have zeros
// 4. After all_sum, all ranks have the file data
// 5. All ranks write the file to disk
//
// For large files, the transfer is chunked to manage memory efficiently.
//
// Usage:
// Set environment variables (see README.md), then run:
//
// ./jaccl_file_broadcast -f <file> [-s <sender_rank>] [-o <output_dir>]
//
// Or with mlx.launch:
//
// mlx.launch --hostfile hosts.json ./jaccl_file_broadcast -f myfile.bin
//
// Example output (4 ranks, sender rank 2):
// Rank 0 of 4: Received 10485760 bytes from rank 2 (982.5 MB/s)
// Rank 1 of 4: Received 10485760 bytes from rank 2 (985.2 MB/s)
// Rank 2 of 4: Sent 10485760 bytes (980.1 MB/s)
// Rank 3 of 4: Received 10485760 bytes from rank 2 (978.9 MB/s)
#include <jaccl/jaccl.h>
#include <jaccl/types.h>
#include <sys/stat.h>
#include <atomic>
#include <chrono>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <iostream>
#include <string>
#include <thread>
#include <vector>
static void usage(const char* prog) {
std::cerr
<< "Usage: " << prog << " [options]\n"
<< " -f <file> File to broadcast (required)\n"
<< " -s <rank> Sender rank (default: 0)\n"
<< " -o <dir> Output directory (default: current dir)\n"
<< " -c <bytes> Chunk size in bytes (default: 67108864 = 64MB)\n"
<< " -v Verbose output\n"
<< " -h Show this help\n";
}
static bool file_exists(const std::string& path) {
struct stat buffer;
return (stat(path.c_str(), &buffer) == 0);
}
static std::int64_t file_size(const std::string& path) {
struct stat buffer;
if (stat(path.c_str(), &buffer) != 0) {
return -1;
}
return static_cast<std::int64_t>(buffer.st_size);
}
static bool create_directory(const std::string& path) {
if (path.empty() || path == ".") {
return true;
}
return mkdir(path.c_str(), 0755) == 0 || errno == EEXIST;
}
static std::string basename(const std::string& path) {
size_t pos = path.find_last_of("/\\");
return (pos == std::string::npos) ? path : path.substr(pos + 1);
}
struct BroadcastStats {
std::int64_t total_bytes;
std::int64_t chunks_sent;
std::int64_t chunks_received;
double total_time_ms;
int sender_rank;
};
int main(int argc, char** argv) {
std::string input_file;
std::string output_dir = ".";
int sender_rank = 0;
std::int64_t chunk_size = 67108864;
bool verbose = false;
for (int i = 1; i < argc; i++) {
std::string arg = argv[i];
if (arg == "-h" || arg == "--help") {
usage(argv[0]);
return 0;
} else if (arg == "-f" && i + 1 < argc) {
input_file = argv[++i];
} else if (arg == "-s" && i + 1 < argc) {
sender_rank = std::atoi(argv[++i]);
} else if (arg == "-o" && i + 1 < argc) {
output_dir = argv[++i];
} else if (arg == "-c" && i + 1 < argc) {
chunk_size = std::atoll(argv[++i]);
} else if (arg == "-v" || arg == "--verbose") {
verbose = true;
} else {
std::cerr << "Unknown option: " << arg << "\n";
usage(argv[0]);
return 1;
}
}
if (input_file.empty()) {
std::cerr << "Error: Input file is required (-f <file>)\n";
usage(argv[0]);
return 1;
}
auto group = jaccl::init();
if (!group) {
std::cerr << "Failed to initialize JACCL" << std::endl;
return 1;
}
int rank = group->rank();
int nranks = group->size();
if (sender_rank < 0 || sender_rank >= nranks) {
std::cerr << "Error: Sender rank " << sender_rank << " is out of range [0, "
<< nranks << ")\n";
return 1;
}
std::int64_t total_file_size = 0;
if (rank == sender_rank) {
if (!file_exists(input_file)) {
std::cerr << "Error: File not found: " << input_file << "\n";
return 1;
}
total_file_size = file_size(input_file);
if (total_file_size < 0) {
std::cerr << "Error: Cannot read file size: " << input_file << "\n";
return 1;
}
}
group->all_sum(
&total_file_size, &total_file_size, sizeof(int64_t), jaccl::Int64);
if (!create_directory(output_dir)) {
std::cerr << "Error: Cannot create output directory: " << output_dir
<< "\n";
return 1;
}
std::string output_file = output_dir == "."
? basename(input_file)
: output_dir + "/" + basename(input_file);
if (verbose) {
std::printf(
"Rank %d of %d: Broadcasting '%s' (%ld bytes) from rank %d\n",
rank,
nranks,
input_file.c_str(),
static_cast<long>(total_file_size),
sender_rank);
}
auto t_start = std::chrono::high_resolution_clock::now();
std::int64_t num_chunks = (total_file_size + chunk_size - 1) / chunk_size;
if (num_chunks == 0) {
num_chunks = 1;
}
const int num_buffers = 4;
std::vector<std::vector<std::uint8_t>> buffers(
num_buffers, std::vector<std::uint8_t>(chunk_size, 0));
std::ifstream infile;
std::ofstream outfile;
if (rank == sender_rank) {
infile.open(input_file, std::ios::binary);
if (!infile.good()) {
std::cerr << "Error: Cannot open input file: " << input_file << "\n";
return 1;
}
}
outfile.open(output_file, std::ios::binary);
if (!outfile.good()) {
std::cerr << "Error: Cannot open output file: " << output_file << "\n";
return 1;
}
std::atomic<std::int64_t> next_read_chunk{0};
std::atomic<std::int64_t> next_comm_chunk{0};
std::atomic<std::int64_t> next_write_chunk{0};
std::atomic<bool> read_done{false};
std::atomic<bool> comm_done{false};
std::vector<std::atomic<bool>> buffer_ready(num_buffers);
std::vector<std::atomic<bool>> buffer_written(num_buffers);
for (int i = 0; i < num_buffers; i++) {
buffer_ready[i] = false;
buffer_written[i] = false;
}
std::vector<std::int64_t> chunk_sizes(num_chunks);
for (std::int64_t i = 0; i < num_chunks; i++) {
chunk_sizes[i] = std::min(chunk_size, total_file_size - i * chunk_size);
}
std::thread reader_thread;
if (rank == sender_rank) {
reader_thread = std::thread([&]() {
while (true) {
std::int64_t chunk_idx = next_read_chunk.fetch_add(1);
if (chunk_idx >= num_chunks) {
break;
}
std::int64_t offset = chunk_idx * chunk_size;
std::int64_t this_chunk_size = chunk_sizes[chunk_idx];
int buffer_idx = chunk_idx % num_buffers;
infile.seekg(offset, std::ios::beg);
infile.read(
reinterpret_cast<char*>(buffers[buffer_idx].data()),
this_chunk_size);
std::fill(
buffers[buffer_idx].begin() + this_chunk_size,
buffers[buffer_idx].end(),
0);
buffer_ready[buffer_idx] = true;
}
read_done = true;
});
} else {
read_done = true;
}
std::thread writer_thread([&]() {
while (true) {
std::int64_t chunk_idx = next_write_chunk.load();
if (chunk_idx >= num_chunks && comm_done) {
break;
}
if (chunk_idx >= num_chunks) {
std::this_thread::yield();
continue;
}
int buffer_idx = chunk_idx % num_buffers;
if (!buffer_written[buffer_idx]) {
std::this_thread::yield();
continue;
}
std::int64_t this_chunk_size = chunk_sizes[chunk_idx];
outfile.write(
reinterpret_cast<const char*>(buffers[buffer_idx].data()),
this_chunk_size);
buffer_written[buffer_idx] = false;
next_write_chunk.fetch_add(1);
}
});
for (std::int64_t chunk_idx = 0; chunk_idx < num_chunks; chunk_idx++) {
std::int64_t this_chunk_size = chunk_sizes[chunk_idx];
int buffer_idx = chunk_idx % num_buffers;
if (rank == sender_rank) {
while (!buffer_ready[buffer_idx] && !read_done) {
std::this_thread::yield();
}
}
std::fill(
buffers[buffer_idx].begin() + this_chunk_size,
buffers[buffer_idx].end(),
0);
group->all_sum(
buffers[buffer_idx].data(),
buffers[buffer_idx].data(),
this_chunk_size,
jaccl::UInt8);
buffer_written[buffer_idx] = true;
next_comm_chunk.fetch_add(1);
if (verbose) {
double progress = 100.0 * (chunk_idx + 1) / num_chunks;
std::printf(
"Rank %d: Progress %.1f%% (%ld/%ld chunks)\n",
rank,
progress,
static_cast<long>(chunk_idx + 1),
static_cast<long>(num_chunks));
}
}
comm_done = true;
if (reader_thread.joinable()) {
reader_thread.join();
}
writer_thread.join();
infile.close();
outfile.close();
auto t_end = std::chrono::high_resolution_clock::now();
double elapsed_ms =
std::chrono::duration<double, std::milli>(t_end - t_start).count();
double elapsed_sec = elapsed_ms / 1000.0;
double bandwidth_mbps = (total_file_size / (1024.0 * 1024.0)) / elapsed_sec;
if (rank == sender_rank) {
std::printf(
"Rank %d of %d: Sent %ld bytes from '%s' (%.1f MB/s)\n",
rank,
nranks,
static_cast<long>(total_file_size),
input_file.c_str(),
bandwidth_mbps);
} else {
std::printf(
"Rank %d of %d: Received %ld bytes from rank %d to '%s' (%.1f MB/s)\n",
rank,
nranks,
static_cast<long>(total_file_size),
sender_rank,
output_file.c_str(),
bandwidth_mbps);
}
if (verbose) {
std::printf(
"Rank %d: Total time: %.2f ms, Chunks: %ld, Chunk size: %ld bytes\n",
rank,
elapsed_ms,
static_cast<long>(num_chunks),
static_cast<long>(chunk_size));
}
return 0;
}
@@ -0,0 +1,152 @@
// Copyright © 2025 Apple Inc.
//
// Monte Carlo Pi Estimation with JACCL
//
// This example demonstrates distributed Monte Carlo simulation using JACCL
// to estimate the value of π. Each rank generates random points independently
// and uses all-reduce to aggregate the results across all machines.
//
// The algorithm:
// 1. Each rank generates N random points in the unit square [0,1] x [0,1]
// 2. Count how many fall inside the quarter circle (x² + y² ≤ 1)
// 3. Use all_sum to aggregate hits and total points across all ranks
// 4. π ≈ 4 × (hits / total)
//
// Usage:
// Set environment variables (see README.md), then run:
//
// ./jaccl_monte_carlo_pi [-n <points_per_rank>]
//
// Or with mlx.launch:
//
// mlx.launch --hostfile hosts.json ./jaccl_monte_carlo_pi -n 10000000
//
// Example output (4 ranks, 10M points each):
// Rank 2 of 4
// Local: 7854321 hits out of 10000000 points
// Global: 31416789 hits out of 40000000 points
// Estimated π = 3.141679 (error: 0.000086)
#include <jaccl/jaccl.h>
#include <jaccl/types.h>
#include <chrono>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <random>
#include <string>
#include <vector>
static void usage(const char* prog) {
std::cerr << "Usage: " << prog << " [options]\n"
<< " -n <points> Points per rank (default: 1000000)\n"
<< " -s <seed> Random seed base (default: 42)\n"
<< " -h Show this help\n";
}
struct MonteCarloResult {
int64_t hits;
int64_t total;
};
MonteCarloResult estimate_pi_local(int64_t num_points, unsigned int seed) {
std::mt19937_64 rng(seed);
std::uniform_real_distribution<double> dist(0.0, 1.0);
int64_t hits = 0;
for (int64_t i = 0; i < num_points; i++) {
double x = dist(rng);
double y = dist(rng);
if (x * x + y * y <= 1.0) {
hits++;
}
}
return {hits, num_points};
}
int main(int argc, char** argv) {
int64_t points_per_rank = 1000000;
unsigned int seed_base = 42;
for (int i = 1; i < argc; i++) {
std::string arg = argv[i];
if (arg == "-h" || arg == "--help") {
usage(argv[0]);
return 0;
} else if (arg == "-n" && i + 1 < argc) {
points_per_rank = std::atoll(argv[++i]);
} else if (arg == "-s" && i + 1 < argc) {
seed_base = static_cast<unsigned int>(std::atoi(argv[++i]));
} else {
std::cerr << "Unknown option: " << arg << "\n";
usage(argv[0]);
return 1;
}
}
auto group = jaccl::init();
if (!group) {
std::cerr << "Failed to initialize JACCL" << std::endl;
return 1;
}
int rank = group->rank();
int nranks = group->size();
std::printf("Rank %d of %d\n", rank, nranks);
std::printf(
"Generating %ld random points (seed: %u)...\n",
static_cast<long>(points_per_rank),
seed_base + static_cast<unsigned int>(rank));
auto t0 = std::chrono::high_resolution_clock::now();
MonteCarloResult local = estimate_pi_local(
points_per_rank, seed_base + static_cast<unsigned int>(rank));
auto t1 = std::chrono::high_resolution_clock::now();
double local_time =
std::chrono::duration<double, std::milli>(t1 - t0).count();
std::printf(
"Rank %d: %ld hits out of %ld points (%.2f ms)\n",
rank,
static_cast<long>(local.hits),
static_cast<long>(local.total),
local_time);
MonteCarloResult global = {0, 0};
group->all_sum(&local.hits, &global.hits, sizeof(int64_t), jaccl::Int64);
group->all_sum(&local.total, &global.total, sizeof(int64_t), jaccl::Int64);
if (rank == 0) {
double pi_estimate = 4.0 * static_cast<double>(global.hits) /
static_cast<double>(global.total);
double error = std::abs(pi_estimate - M_PI);
std::printf("\n=== Results ===\n");
std::printf(
"Global: %ld hits out of %ld points\n",
static_cast<long>(global.hits),
static_cast<long>(global.total));
std::printf("Estimated π = %.10f\n", pi_estimate);
std::printf("True π = %.10f\n", M_PI);
std::printf("Error = %.10f (%.6f%%)\n", error, 100.0 * error / M_PI);
double total_time =
std::chrono::duration<double, std::milli>(t1 - t0).count();
std::printf("\nPerformance:\n");
std::printf("Total points: %ld\n", static_cast<long>(global.total));
std::printf("Time: %.2f ms\n", total_time);
std::printf(
"Points/sec: %.0f\n",
static_cast<double>(global.total) / (total_time / 1000.0));
}
return 0;
}