Merge cb4dc59a9e into 5adf185f86

* perf tuning

* fix adding inputs arrays in matmul / srot

* format

* fix

.circleci/config.yml

@@ -16,6 +16,9 @@ parameters:
   linux_release:
     type: boolean
     default: false
+  cuda_release:
+    type: boolean
+    default: false
 
 jobs:
   build_documentation:
@@ -104,7 +107,7 @@ jobs:
           command: |
             echo "stubs"
             pip install typing_extensions
-            python setup.py generate_stubs 
+            python setup.py generate_stubs
       - run:
           name: Run Python tests
           command: |
@@ -162,7 +165,7 @@ jobs:
           command: |
             source env/bin/activate
             pip install typing_extensions
-            python setup.py generate_stubs 
+            python setup.py generate_stubs
       - run:
           name: Run Python tests
           command: |
@@ -223,7 +226,6 @@ jobs:
           command: |
             sudo apt-get update
             sudo apt-get install libblas-dev liblapack-dev liblapacke-dev
-            sudo apt-get install openmpi-bin openmpi-common libopenmpi-dev
             python -m venv env
             source env/bin/activate
             CMAKE_BUILD_PARALLEL_LEVEL=`nproc` \
@@ -283,7 +285,7 @@ jobs:
           command: |
             source env/bin/activate
             pip install typing_extensions
-            python setup.py generate_stubs 
+            python setup.py generate_stubs
       - run:
           name: Build Python package
           command: |
@@ -342,7 +344,7 @@ jobs:
               CMAKE_BUILD_PARALLEL_LEVEL=`nproc` \
               pip install . -v
             pip install typing_extensions
-            python setup.py generate_stubs 
+            python setup.py generate_stubs
             << parameters.extra_env >> \
               CMAKE_BUILD_PARALLEL_LEVEL=`nproc` \
               python -m build --wheel
@@ -356,6 +358,48 @@ jobs:
       - store_artifacts:
           path: wheelhouse/
 
+  build_cuda_release:
+    parameters:
+      python_version:
+        type: string
+        default: "3.9"
+      extra_env:
+        type: string
+        default: "DEV_RELEASE=1"
+    machine:
+      image: linux-cuda-12:default
+      resource_class: gpu.nvidia.small.gen2
+    steps:
+      - checkout
+      - run:
+          name: Build wheel
+          command: |
+            sudo apt-get update
+            sudo apt-get install libblas-dev liblapack-dev liblapacke-dev
+            python -m venv env
+            source env/bin/activate
+            pip install auditwheel
+            pip install patchelf
+            pip install build
+            pip install twine
+            << parameters.extra_env >> \
+              CMAKE_BUILD_PARALLEL_LEVEL=`nproc` \
+              CMAKE_ARGS="-DMLX_BUILD_CUDA=ON -DCMAKE_CUDA_COMPILER=`which nvcc`" \
+              pip install ".[dev]" -v
+            python setup.py generate_stubs
+            << parameters.extra_env >> \
+              CMAKE_BUILD_PARALLEL_LEVEL=`nproc` \
+              CMAKE_ARGS="-DMLX_BUILD_CUDA=ON -DCMAKE_CUDA_COMPILER=`which nvcc`" \
+              python -m build --wheel
+            bash python/scripts/repair_cuda.sh
+      - run:
+          name: Upload package
+          command: |
+            source env/bin/activate
+            twine upload wheelhouse/*.whl
+      - store_artifacts:
+          path: wheelhouse/
+
 workflows:
   build_and_test:
     when:
@@ -625,3 +669,14 @@ workflows:
             parameters:
               python_version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
               extra_env: ["PYPI_RELEASE=1"]
+  cuda_test_release:
+    when:
+      and:
+        - equal: [ main, << pipeline.git.branch >> ]
+        - << pipeline.parameters.cuda_release >>
+    jobs:
+      - build_cuda_release:
+          matrix:
+            parameters:
+              python_version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
+              extra_env: ["PYPI_RELEASE=1"]

docs/src/install.rst

@@ -30,6 +30,16 @@ MLX is also available on conda-forge. To install MLX with conda do:
 
    conda install conda-forge::mlx
 
+CUDA
+^^^^
+
+MLX has a CUDA backend which you can use on any Linux platform with CUDA 12
+and SM 7.0 (Volta) and up. To install MLX with CUDA support, run:
+
+.. code-block:: shell
+
+    pip install mlx-cuda
+
 
 Troubleshooting
 ^^^^^^^^^^^^^^^
@@ -65,6 +75,8 @@ Build Requirements
 Python API
 ^^^^^^^^^^
 
+.. _python install:
+
 To build and install the MLX python library from source, first, clone MLX from
 `its GitHub repo <https://github.com/ml-explore/mlx>`_:
 
@@ -107,6 +119,8 @@ IDE:
 C++ API
 ^^^^^^^
 
+.. _cpp install:
+
 Currently, MLX must be built and installed from source.
 
 Similarly to the python library, to build and install the MLX C++ library start
@@ -185,6 +199,7 @@ should point to the path to the built metal library.
 
       xcrun -sdk macosx --show-sdk-version
 
+
 Binary Size Minimization
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -213,6 +228,50 @@ be anwywhere from a few hundred millisecond to a few seconds depending on the
 application. Once a kernel is compiled, it will be cached by the system. The
 Metal kernel cache persists across reboots.
 
+Linux
+^^^^^
+
+To build from source on Linux (CPU only), install the BLAS and LAPACK headers.
+For example on Ubuntu, run the following:
+
+.. code-block:: shell
+
+   apt-get update -y
+   apt-get install libblas-dev liblapack-dev liblapacke-dev -y
+
+From here follow the instructions to install either the :ref:`Python <python
+install>` or :ref:`C++ <cpp install>` APIs.
+
+CUDA
+^^^^
+
+To build from source on Linux with CUDA, install the BLAS and LAPACK headers
+and the CUDA toolkit. For example on Ubuntu, run the following:
+
+.. code-block:: shell
+
+   wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2204/x86_64/cuda-keyring_1.1-1_all.deb
+   dpkg -i cuda-keyring_1.1-1_all.deb
+   apt-get update -y
+   apt-get -y install cuda-toolkit-12-9
+   apt-get install libblas-dev liblapack-dev liblapacke-dev -y
+
+
+When building either the Python or C++ APIs make sure to pass the cmake flag
+``MLX_BUILD_CUDA=ON``. For example, to build the Python API run:
+
+.. code-block:: shell
+
+  CMAKE_BUILD_PARALLEL_LEVEL=8 CMAKE_ARGS="-DMLX_BUILD_CUDA=ON" pip install -e ".[dev]"
+
+To build the C++ package run:
+
+.. code-block:: shell
+
+   mkdir -p build && cd build
+   cmake .. -DMLX_BUILD_CUDA=ON && make -j
+
+
 Troubleshooting
 ^^^^^^^^^^^^^^^
 

mlx/backend/cuda/allocator.cpp

@@ -3,6 +3,7 @@
 #include "mlx/backend/cuda/allocator.h"
 #include "mlx/backend/cuda/utils.h"
 #include "mlx/backend/cuda/worker.h"
+#include "mlx/utils.h"
 
 #include <cuda_runtime.h>
 #include <fmt/format.h>
@@ -14,9 +15,11 @@ namespace mlx::core {
 
 namespace cu {
 
+constexpr int page_size = 16384;
+
 CudaAllocator::CudaAllocator()
     : buffer_cache_(
-          getpagesize(),
+          page_size,
           [](CudaBuffer* buf) { return buf->size; },
           [this](CudaBuffer* buf) {
             cuda_free(buf->data);
@@ -31,7 +34,14 @@ CudaAllocator::CudaAllocator()
 
 Buffer CudaAllocator::malloc(size_t size) {
   // Find available buffer from cache.
+  auto orig_size = size;
   std::unique_lock lock(mutex_);
+  if (size < page_size) {
+    size = next_power_of_2(size);
+  } else {
+    size = page_size * ((size + page_size - 1) / page_size);
+  }
+
   CudaBuffer* buf = buffer_cache_.reuse_from_cache(size);
   if (!buf) {
     // If we have a lot of memory pressure or are over the maximum cache size,

mlx/backend/cuda/copy.cu

@@ -24,7 +24,6 @@ void copy_gpu_inplace(
   auto& encoder = cu::get_command_encoder(s);
   encoder.set_input_array(in);
   encoder.set_output_array(out);
-
   if (ctype == CopyType::Scalar || ctype == CopyType::Vector) {
     copy_contiguous(encoder, ctype, in, out, offset_in, offset_out);
     return;

mlx/backend/cuda/device.cpp

@@ -114,7 +114,7 @@ void CommandEncoder::synchronize() {
   std::future<void> f = p->get_future();
   add_completed_handler([p = std::move(p)]() { p->set_value(); });
   worker_.end_batch();
-  worker_.commit();
+  commit();
   f.wait();
 }
 

mlx/backend/cuda/device/utils.cuh

@@ -155,8 +155,8 @@ inline __host__ __device__ cuda::std::tuple<IdxT, IdxT> elem_to_loc_nd(
 #pragma unroll
   for (int i = NDIM - 1; i >= 0; --i) {
     int dim_idx = elem % shape[i];
-    a_loc += dim_idx * a_strides[i];
-    b_loc += dim_idx * b_strides[i];
+    a_loc += dim_idx * IdxT(a_strides[i]);
+    b_loc += dim_idx * IdxT(b_strides[i]);
     elem /= shape[i];
   }
   return cuda::std::make_tuple(a_loc, b_loc);
@@ -175,9 +175,9 @@ inline __host__ __device__ cuda::std::tuple<IdxT, IdxT, IdxT> elem_to_loc_nd(
 #pragma unroll
   for (int i = NDIM - 1; i >= 0; --i) {
     int dim_idx = elem % shape[i];
-    a_loc += dim_idx * a_strides[i];
-    b_loc += dim_idx * b_strides[i];
-    c_loc += dim_idx * c_strides[i];
+    a_loc += dim_idx * IdxT(a_strides[i]);
+    b_loc += dim_idx * IdxT(b_strides[i]);
+    c_loc += dim_idx * IdxT(c_strides[i]);
     elem /= shape[i];
   }
   return cuda::std::make_tuple(a_loc, b_loc, c_loc);
@@ -206,8 +206,8 @@ inline __host__ __device__ cuda::std::tuple<IdxT, IdxT> elem_to_loc_4d(
   IdxT b_loc = 0;
   for (int i = ndim - 1; i >= 0; --i) {
     int dim_idx = elem % shape[i];
-    a_loc += dim_idx * a_strides[i];
-    b_loc += dim_idx * b_strides[i];
+    a_loc += dim_idx * IdxT(a_strides[i]);
+    b_loc += dim_idx * IdxT(b_strides[i]);
     elem /= shape[i];
   }
   return cuda::std::make_tuple(a_loc, b_loc);
@@ -226,9 +226,9 @@ inline __host__ __device__ cuda::std::tuple<IdxT, IdxT, IdxT> elem_to_loc_4d(
   IdxT c_loc = 0;
   for (int i = ndim - 1; i >= 0; --i) {
     int dim_idx = elem % shape[i];
-    a_loc += dim_idx * a_strides[i];
-    b_loc += dim_idx * b_strides[i];
-    c_loc += dim_idx * c_strides[i];
+    a_loc += dim_idx * IdxT(a_strides[i]);
+    b_loc += dim_idx * IdxT(b_strides[i]);
+    c_loc += dim_idx * IdxT(c_strides[i]);
     elem /= shape[i];
   }
   return cuda::std::make_tuple(a_loc, b_loc, c_loc);

mlx/backend/cuda/matmul.cpp

@@ -162,11 +162,15 @@ class MatMul {
       }
     }
 
-    array workspace(
-        allocator::malloc(heuristic_.workspaceSize),
-        {static_cast<int>(heuristic_.workspaceSize)},
-        int8);
-    encoder.add_temporary(workspace);
+    void* workspace_ptr = nullptr;
+    if (heuristic_.workspaceSize > 0) {
+      array workspace(
+          allocator::malloc(heuristic_.workspaceSize),
+          {static_cast<int>(heuristic_.workspaceSize)},
+          int8);
+      encoder.add_temporary(workspace);
+      workspace_ptr = workspace.data<void>();
+    }
 
     encoder.launch_kernel([&](cudaStream_t stream) {
       CHECK_CUBLAS_ERROR(cublasLtMatmul(
@@ -183,8 +187,8 @@ class MatMul {
           out,
           out_desc_,
           &heuristic_.algo,
-          workspace.data<void>(),
-          workspace.nbytes(),
+          workspace_ptr,
+          heuristic_.workspaceSize,
           stream));
     });
   }
@@ -358,9 +362,18 @@ void Matmul::eval_gpu(const std::vector<array>& inputs, array& out) {
       a_batch_strides.back(),
       b_batch_strides.back());
 
+  encoder.set_input_array(a);
+  encoder.set_input_array(b);
+  encoder.set_output_array(out);
+  auto nbatch = batch_count / batch_shape.back();
+  if (nbatch == 1) {
+    matmul.run(encoder, out.data<int8_t>(), a.data<int8_t>(), b.data<int8_t>());
+    return;
+  }
+
   ContiguousIterator a_it(batch_shape, a_batch_strides, batch_shape.size() - 1);
   ContiguousIterator b_it(batch_shape, b_batch_strides, batch_shape.size() - 1);
-  for (size_t i = 0; i < batch_count / batch_shape.back(); ++i) {
+  for (size_t i = 0; i < nbatch; ++i) {
     matmul.run(
         encoder,
         out.data<int8_t>() + out.itemsize() * i * batch_shape.back() * M * N,
@@ -444,10 +457,28 @@ void AddMM::eval_gpu(const std::vector<array>& inputs, array& out) {
       b_batch_strides.back(),
       c_batch_strides.back());
 
+  encoder.set_input_array(a);
+  encoder.set_input_array(b);
+  encoder.set_input_array(c);
+  encoder.set_output_array(out);
+
+  auto nbatch = batch_count / batch_shape.back();
+  if (nbatch == 1) {
+    matmul.run(
+        encoder,
+        out.data<int8_t>(),
+        a.data<int8_t>(),
+        b.data<int8_t>(),
+        c.data<int8_t>(),
+        alpha_,
+        beta_);
+    return;
+  }
+
   ContiguousIterator a_it(batch_shape, a_batch_strides, batch_shape.size() - 1);
   ContiguousIterator b_it(batch_shape, b_batch_strides, batch_shape.size() - 1);
   ContiguousIterator c_it(batch_shape, c_batch_strides, batch_shape.size() - 1);
-  for (size_t i = 0; i < batch_count / batch_shape.back(); ++i) {
+  for (size_t i = 0; i < nbatch; ++i) {
     matmul.run(
         encoder,
         out.data<int8_t>() + out.itemsize() * i * batch_shape.back() * M * N,

mlx/backend/cuda/sort.cu

@@ -79,9 +79,6 @@ void segmented_sort(cu::CommandEncoder& encoder, Args&&... args) {
 void gpu_sort(const Stream& s, array in, array& out_, int axis, bool argsort) {
   array out = out_;
   auto& encoder = cu::get_command_encoder(s);
-  encoder.set_input_array(in);
-  encoder.set_output_array(out);
-
   if (axis < 0) {
     axis += in.ndim();
   }
@@ -106,6 +103,8 @@ void gpu_sort(const Stream& s, array in, array& out_, int axis, bool argsort) {
         in.flags());
   }
 
+  encoder.set_input_array(in);
+  encoder.set_output_array(out);
   encoder.launch_kernel([&](cudaStream_t stream) {
     MLX_SWITCH_ALL_TYPES(in.dtype(), CTYPE, {
       if constexpr (!std::is_same_v<CTYPE, complex64_t>) {

python/mlx/nn/layers/base.py

@@ -413,7 +413,7 @@ class Module(dict):
                             f'Module does not have sub-module named "{k}".'
                         )
             elif isinstance(modules, list):
-                for i in range(len(dst)):
+                for i in range(len(modules)):
                     current_value = dst[i]
                     new_value = modules[i]
                     if self.is_module(current_value) and self.is_module(new_value):

python/scripts/repair_cuda.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+auditwheel repair dist/* \
+  --plat manylinux_2_35_x86_64 \
+  --exclude libcublas* \
+  --exclude libnvrtc*
+
+cd wheelhouse
+repaired_wheel=$(find . -name "*.whl" -print -quit)
+unzip -q "${repaired_wheel}"
+core_so=$(find mlx -name "core*.so" -print -quit)
+rpath=$(patchelf --print-rpath "${core_so}")
+rpath=$rpath:\$ORIGIN/../nvidia/cublas/lib:\$ORIGIN/../nvidia/cuda_nvrtc/lib
+patchelf --force-rpath --set-rpath "$rpath" "$core_so"
+
+# Re-zip the repaired wheel
+zip -r -q "${repaired_wheel}" .

python/tests/test_nn.py

@@ -259,6 +259,11 @@ class TestBase(mlx_tests.MLXTestCase):
         with self.assertRaises(ValueError):
             m = m.update_modules({"list": ["hi"]})
 
+        # Allow updating a strict subset
+        m = nn.Sequential(nn.Linear(3, 3), nn.Linear(3, 3))
+        m.update_modules({"layers": [{}, nn.Linear(3, 4)]})
+        self.assertEqual(m.layers[1].weight.shape, (4, 3))
+
 
 class TestLayers(mlx_tests.MLXTestCase):
     def test_identity(self):

setup.py

@@ -174,20 +174,26 @@ if __name__ == "__main__":
     )
     package_dir = {"": "python"}
     package_data = {"mlx": ["lib/*", "include/*", "share/*"], "mlx.core": ["*.pyi"]}
+    install_requires = []
+    build_cuda = "MLX_BUILD_CUDA=ON" in os.environ.get("CMAKE_ARGS", "")
+    if build_cuda:
+        install_requires = ["nvidia-cublas-cu12", "nvidia-cuda-nvrtc-cu12"]
 
     setup(
-        name="mlx",
+        name="mlx-cuda" if build_cuda else "mlx",
         version=get_version(),
         author="MLX Contributors",
         author_email="mlx@group.apple.com",
         description="A framework for machine learning on Apple silicon.",
         long_description=long_description,
         long_description_content_type="text/markdown",
+        license="MIT",
         url="https://github.com/ml-explore/mlx",
         packages=packages,
         package_dir=package_dir,
         package_data=package_data,
         include_package_data=True,
+        install_requires=install_requires,
         extras_require={
             "dev": [
                 "nanobind==2.4.0",