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29_Matmul_Mish_Mishmatmul_mish_coalesced_base

Level 2 • Task 29
import torch
import torch.nn as nn
import torch.nn.functional as F


def module_fn(
    x: torch.Tensor,
    weight: torch.Tensor,
    bias: torch.Tensor,
) -> torch.Tensor:
    """
    Applies linear transformation followed by two Mish activations.

    Args:
        x (torch.Tensor): Input tensor of shape (batch_size, in_features)
        weight (torch.Tensor): Weight matrix of shape (out_features, in_features)
        bias (torch.Tensor): Bias vector of shape (out_features)

    Returns:
        torch.Tensor: Output tensor after linear transformation and two Mish activations,
            with shape (batch_size, out_features)
    """
    x = F.linear(x, weight, bias)
    x = F.mish(x)
    x = F.mish(x)
    return x


class Model(nn.Module):
    """
    Simple model that performs a matrix multiplication, applies Mish, and applies Mish again.
    """

    def __init__(self, in_features, out_features):
        super(Model, self).__init__()
        linear = nn.Linear(in_features, out_features)
        self.weight = nn.Parameter(linear.weight)
        self.bias = nn.Parameter(linear.bias + torch.ones_like(linear.bias) * 0.02)

    def forward(self, x, fn=module_fn):
        return fn(x, self.weight, self.bias)


batch_size = 128
in_features = 10
out_features = 20


def get_inputs():
    return [torch.randn(batch_size, in_features)]


def get_init_inputs():
    return [in_features, out_features]
import torch
import torch.nn as nn

class Model(nn.Module):
    """
    Simple model that performs a matrix multiplication, applies Mish, and applies Mish again.
    """
    def __init__(self, in_features, out_features):
        super(Model, self).__init__()
        self.linear = nn.Linear(in_features, out_features)
        self.linear.bias = nn.Parameter(self.linear.bias + torch.ones_like(self.linear.bias) * 0.02)

    def forward(self, x):
        x = self.linear(x)
        x = torch.nn.functional.mish(x)
        x = torch.nn.functional.mish(x)
        return x

batch_size = 128
in_features = 10
out_features = 20

def get_inputs():
    return [torch.randn(batch_size, in_features)]

def get_init_inputs():
    return [in_features, out_features]

Kernel Information

Related Kernels (Level 2, Task 29 • 29_Matmul_Mish_Mish)

Rank Kernel Name Runtime (ms) Speedup Native Speedup Compile
🥇 29_Matmul_Mish_Mish 0.01 3.65 9.33
🥇 aligned_ldg_29_matmul_mish_mish_base 0.01 3.65 9.33
🥇 optimized_ldg_matmul_mish_base 0.01 3.65 9.33
🥇 stride_loop_optimized_matmul_mish_base 0.01 3.65 9.33
🥇 optimized_tiled_kernel_base 0.01 3.65 9.33
🥇 uniform_control_flow_optimized_matmul_mish_base 0.01 3.65 9.33
🥇 matmul_mish_coalesced_base 0.01 3.65 9.33
🥇 fast_mish_tiled_base 0.01 3.65 9.33
🥇 unrolled_tiled_matmul_mish_base 0.01 3.65 9.33
🥇 matmul_mish_unroll_edit_1 0.01 3.65 9.33
🥇 matmul_mish_aligned_ldg_base 0.01 3.65 9.33
🥇 matmul_mish_aligned_ldg_edit_1 0.01 3.65 9.33
🥇 matmul_mish_coalesced_edit_1 0.01 3.65 9.33
🥇 modular_matmul_mish_base 0.01 3.65 9.33
🥇 strided_thread_parallel_base 0.01 3.65 9.33
🥇 strided_thread_parallel_edit_1 0.01 3.65 9.33
🥇 modular_strided_thread_parallel_base 0.01 3.65 9.33
🥇 warp_reduce_dot_product_base_base 0.01 3.65 9.33
🥇 warp_reduction_dot_base 0.01 3.65 9.33
🥇 tuned_block_size_128_base 0.01 3.65 9.33
#include <torch/extension.h>
#include <ATen/cuda/CUDAContext.h>
#include <cuda.h>
#include <cuda_runtime.h>
#include <cmath>

// Tile dimension chosen to match warp sizes and shared memory limitations
#define TILE_DIM 16

// Device function for softplus
__device__ float softplus_func(float x) {
    float abs_x = fabsf(x);
    float z = expf(-abs_x);
    return fmaxf(x, 0.0f) + log1pf(z);
}

// Device function for Mish activation
__device__ float mish_func(float x) {
    float sp = softplus_func(x);
    return x * tanhf(sp);
}

// Tiled kernel performing matrix multiplication x * weight^T, adding bias, and applying two Mish activations
// x: [M x K]
// weight: [N x K] where each row corresponds to weight for an output; used as weight[n,k]
// bias: [N]
// output: [M x N]
__global__ void forward_kernel(
    const float* __restrict__ x,
    const float* __restrict__ weight,
    const float* __restrict__ bias,
    float* __restrict__ output,
    int M, // batch size
    int K, // in_features
    int N  // out_features
) {
    // 2D indexing for output element
    int row = blockIdx.y * TILE_DIM + threadIdx.y;
    int col = blockIdx.x * TILE_DIM + threadIdx.x;

    float sum = 0.0f;

    // Allocate shared memory tiles for x and weight
    __shared__ float As[TILE_DIM][TILE_DIM];
    __shared__ float Bs[TILE_DIM][TILE_DIM];

    // Loop over tiles along the K dimension
    int numTiles = (K + TILE_DIM - 1) / TILE_DIM;
    for (int t = 0; t < numTiles; t++) {
        // Load tile from x: each thread loads one element if in bounds
        int tiledCol = t * TILE_DIM + threadIdx.x;
        if (row < M && tiledCol < K) {
            As[threadIdx.y][threadIdx.x] = x[row * K + tiledCol];
        } else {
            As[threadIdx.y][threadIdx.x] = 0.0f;
        }

        // Load tile from weight. Note: weight is [N x K] stored row-major so each row is contiguous.
        // For the output element at (row, col), we need weight[col, t * TILE_DIM + i].
        int tiledRow = t * TILE_DIM + threadIdx.y;
        if (col < N && tiledRow < K) {
            Bs[threadIdx.y][threadIdx.x] = weight[col * K + tiledRow];
        } else {
            Bs[threadIdx.y][threadIdx.x] = 0.0f;
        }

        __syncthreads();

        // Multiply the two tiles
        for (int i = 0; i < TILE_DIM; i++) {
            sum += As[threadIdx.y][i] * Bs[i][threadIdx.x];
        }
        __syncthreads();
    }

    // Write result with bias and two cascaded Mish activations
    if (row < M && col < N) {
        float val = sum + bias[col];
        float mish1 = mish_func(val);
        float mish2 = mish_func(mish1);
        output[row * N + col] = mish2;
    }
}

// Host function to setup kernel launch
torch::Tensor forward(
    torch::Tensor x,
    torch::Tensor weight,
    torch::Tensor bias
) {
    TORCH_CHECK(x.dim() == 2, "x must be 2D");
    TORCH_CHECK(weight.dim() == 2, "weight must be 2D");
    TORCH_CHECK(bias.dim() == 1, "bias must be 1D");

    int M = x.size(0);
    int K = x.size(1);
    int N = weight.size(0);

    TORCH_CHECK(weight.size(1) == K, "weight shape mismatch");
    TORCH_CHECK(bias.size(0) == N, "bias shape mismatch");

    auto output = torch::empty({M, N}, x.options());

    dim3 blockDim(TILE_DIM, TILE_DIM);
    dim3 gridDim((N + TILE_DIM - 1) / TILE_DIM, (M + TILE_DIM - 1) / TILE_DIM);

    forward_kernel<<<gridDim, blockDim, 0, at::cuda::getCurrentCUDAStream()>>>(
        x.data_ptr<float>(),
        weight.data_ptr<float>(),
        bias.data_ptr<float>(),
        output.data_ptr<float>(),
        M, K, N
    );

    return output;
}

PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
    m.def("forward", &forward, "Tiled Matmul Mish Mish forward (CUDA) with coalesced memory accesses");
}
Performance Metrics
Metric Value Unit Variance Samples
Executed Ipc Active 0.594 inst/cycle 0.001 5
Executed Ipc Elapsed 0.030 inst/cycle 0.000 5
Issue Slots Busy 15.158 % 0.299 5
Issued Ipc Active 0.606 inst/cycle 0.001 5
SM Busy 15.158 % 0.299 5
Memory Throughput 3118238789.166 byte/second 5321461474430742.000 5
Mem Busy 8.320 % 0.013 5
Max Bandwidth 4.366 % 0.004 5
L1/TEX Hit Rate 52.176 % 0.218 5
L2 Hit Rate 102.392 % 0.027 5
Mem Pipes Busy 0.448 % 0.000 5
Warp Cycles Per Issued Instruction 12.922 cycle 0.009 5
Warp Cycles Per Executed Instruction 13.230 cycle 0.010 5
Avg. Active Threads Per Warp 24.070 0.000 5
Avg. Not Predicated Off Threads Per Warp 23.280 0.000 5
Max Active Clusters 0.000 cluster 0.000 5
Max Cluster Size 8.000 block 0.000 5
Overall GPU Occupancy 0.000 % 0.000 5
Cluster Occupancy 0.000 % 0.000 5
Block Limit SM 32.000 block 0.000 5
Block Limit Registers 8.000 block 0.000 5
Block Limit Shared Mem 21.000 block 0.000 5
Block Limit Warps 8.000 block 0.000 5
Theoretical Active Warps per SM 64.000 warp 0.000 5
Theoretical Occupancy 100.000 % 0.000 5
Achieved Occupancy 12.412 % 0.000 5
Achieved Active Warps Per SM 7.942 warp 0.000 5
Analysis Rules
Rule Description
WRN HighPipeUtilization All compute pipelines are under-utilized. Either this kernel is very small or it doesn't issue enough warps per scheduler. Check the Launch Statistics and Scheduler Statistics sections for further details.
INF CPIStall Check the Warp Stall Sampling (All Cycles) table for the top stall locations in your source based on sampling data. The Kernel Profiling Guide (https://docs.nvidia.com/nsight-compute/ProfilingGuide/index.html#metrics-reference) provides more details on each stall reason.
WRN ThreadDivergence Instructions are executed in warps, which are groups of 32 threads. Optimal instruction throughput is achieved if all 32 threads of a warp execute the same instruction. The chosen launch configuration, early thread completion, and divergent flow control can significantly lower the number of active threads in a warp per cycle. This kernel achieves an average of 24.1 threads being active per cycle. This is further reduced to 23.3 threads per warp due to predication. The compiler may use predication to avoid an actual branch. Instead, all instructions are scheduled, but a per-thread condition code or predicate controls which threads execute the instructions. Try to avoid different execution paths within a warp when possible. In addition, ensure your kernel makes use of Independent Thread Scheduling, which allows a warp to reconverge after a data-dependent conditional block by explicitly calling __syncwarp().
WRN Occupancy This kernel's theoretical occupancy is not impacted by any block limit. The difference between calculated theoretical (100.0%) and measured achieved occupancy (12.4%) can be the result of warp scheduling overheads or workload imbalances during the kernel execution. Load imbalances can occur between warps within a block as well as across blocks of the same kernel. See the CUDA Best Practices Guide (https://docs.nvidia.com/cuda/cuda-c-best-practices-guide/index.html#occupancy) for more details on optimizing occupancy.
Operation / Metric Value Unit
aten::to
CPU Time 659639.24 μs
Device Time 2.66 μs
Self CPU Time 55.40 μs
Self Device Time 0.00 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
aten::_to_copy
CPU Time 659583.84 μs
Device Time 2.66 μs
Self CPU Time 106.04 μs
Self Device Time 0.00 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
aten::empty_strided
CPU Time 659340.31 μs
Device Time 0.00 μs
Self CPU Time 123.24 μs
Self Device Time 0.00 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
cudaDeviceGetStreamPriorityRange
CPU Time 628084.85 μs
Device Time 0.00 μs
Self CPU Time 628084.85 μs
Self Device Time 0.00 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
aten::fill_
CPU Time 44819.57 μs
Device Time 484778.56 μs
Self CPU Time 14352.25 μs
Self Device Time 484778.56 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
cudaLaunchKernel
CPU Time 342115.94 μs
Device Time 13005.77 μs
Self CPU Time 342115.94 μs
Self Device Time 13005.77 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
forward_kernel(float const*, float const*, float const*, float*, int, int, int)
CPU Time 0.00 μs
Device Time 15714.46 μs
Self CPU Time 0.00 μs
Self Device Time 15714.46 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
cudaEventRecord
CPU Time 17349.15 μs
Device Time 25127.92 μs
Self CPU Time 17349.15 μs
Self Device Time 25127.92 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
aten::zero_
CPU Time 56425.36 μs
Device Time 484778.56 μs
Self CPU Time 11620.48 μs
Self Device Time 0.00 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
void at::native::vectorized_elementwise_kernel<4, at::native::FillFunctor<int>, at::detail::Array<char*, 1> >(int, at::native::FillFunctor<int>, at::detail::Array<char*, 1>)
CPU Time 0.00 μs
Device Time 484778.56 μs
Self CPU Time 0.00 μs
Self Device Time 484778.56 μs
CPU Memory Usage 0 B
Device Memory Usage 0 B
Self CPU Memory Usage 0 B
Self Device Memory Usage 0 B
Status: Completed
45302 warnings generated when compiling for host.
Suppressed 45338 warnings (45291 in non-user code, 47 NOLINT).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:29:5 bugprone-easily-swappable-parameters
29 | const float* __restrict__ x,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
30 | const float* __restrict__ weight,
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
31 | const float* __restrict__ bias,
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:29:31: note: the first parameter in the range is 'x'
29 | const float* __restrict__ x,
| ^
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:31:31: note: the last parameter in the range is 'bias'
31 | const float* __restrict__ bias,
| ^~~~
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:38:15: warning: narrowing conversion from 'unsigned int' to signed type 'int' is implementation-defined [bugprone-narrowing-conversions]
38 | int row = blockIdx.y * TILE_DIM + threadIdx.y;
| ^
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:39:15: warning: narrowing conversion from 'unsigned int' to signed type 'int' is implementation-defined [bugprone-narrowing-conversions]
39 | int col = blockIdx.x * TILE_DIM + threadIdx.x;
| ^
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:51:24: warning: narrowing conversion from 'unsigned int' to signed type 'int' is implementation-defined [bugprone-narrowing-conversions]
51 | int tiledCol = t * TILE_DIM + threadIdx.x;
| ^
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:60:24: warning: narrowing conversion from 'unsigned int' to signed type 'int' is implementation-defined [bugprone-narrowing-conversions]
60 | int tiledRow = t * TILE_DIM + threadIdx.y;
| ^
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:87:19: warning: the parameter 'x' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param]
87 | torch::Tensor x,
| ^
| const &
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:88:19: warning: the parameter 'weight' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param]
88 | torch::Tensor weight,
| ^
| const &
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:89:19: warning: the parameter 'bias' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param]
89 | torch::Tensor bias
| ^
| const &
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:95:13: warning: narrowing conversion from 'int64_t' (aka 'long') to signed type 'int' is implementation-defined [bugprone-narrowing-conversions]
95 | int M = x.size(0);
| ^
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:96:13: warning: narrowing conversion from 'int64_t' (aka 'long') to signed type 'int' is implementation-defined [bugprone-narrowing-conversions]
96 | int K = x.size(1);
| ^
/home/robert_sakana_ai/llm_cuda/experiments/20250208_optimize_b5_s4_e1_sweep/level_2/task_29/b1_s3_matmul_mish_coalesced/base/base.cu:97:13: warning: narrowing conversion from 'int64_t' (aka 'long') to signed type 'int' is implementation-defined [bugprone-narrowing-conversions]
97 | int N = weight.size(0);
| ^