
Sarunya developed and optimized high-performance GPU kernels and benchmarking tools for the pytorch/FBGEMM repository, focusing on deep learning inference and training workloads. She engineered robust attention and embedding modules, integrating technologies like CUDA and C++ to improve throughput, correctness, and cross-platform compatibility. Her work included refactoring kernel code for maintainability, implementing deterministic and reproducible attention mechanisms, and enhancing benchmarking accuracy with Python scripting. By addressing race conditions, memory alignment, and platform-specific constraints, Sarunya enabled scalable, reliable deployment of large models. Her contributions demonstrated depth in low-level optimization, performance engineering, and rigorous testing, resulting in more stable and efficient production systems.

Month: 2025-09. This period focused on stabilizing and improving the Cutlass-based Blackwell attention kernel within pytorch/FBGEMM, delivering correctness, determinism, and production reliability. Notable work included addressing stride/contiguity issues in the backward pass and enabling a deterministic mode to ensure reproducible results, alongside a targeted CI stabilization effort by temporarily disabling a failing test in Blackwell FMHA tests while investigation proceeds.
Month: 2025-09. This period focused on stabilizing and improving the Cutlass-based Blackwell attention kernel within pytorch/FBGEMM, delivering correctness, determinism, and production reliability. Notable work included addressing stride/contiguity issues in the backward pass and enabling a deterministic mode to ensure reproducible results, alongside a targeted CI stabilization effort by temporarily disabling a failing test in Blackwell FMHA tests while investigation proceeds.
August 2025: Delivered Cutlass-based FMHA (Fused Multi-Head Attention) integration for Gen-AI on Blackwell within pytorch/FBGEMM, including forward/backward, generation, and MLA paths, with left masking support and a build-time refactor to speed up compilation. Also reorganized Cutlass sources by splitting into dedicated forward/backward files and relaxed backward Q-length constraints to improve flexibility. These changes establish a performant FMHA pathway for Gen-AI workloads while enhancing maintainability and build efficiency.
August 2025: Delivered Cutlass-based FMHA (Fused Multi-Head Attention) integration for Gen-AI on Blackwell within pytorch/FBGEMM, including forward/backward, generation, and MLA paths, with left masking support and a build-time refactor to speed up compilation. Also reorganized Cutlass sources by splitting into dedicated forward/backward files and relaxed backward Q-length constraints to improve flexibility. These changes establish a performant FMHA pathway for Gen-AI workloads while enhancing maintainability and build efficiency.
In July 2025, completed a focused codebase refactor in pytorch/FBGEMM to improve CUDA attention module organization. By moving GQA split-K CUDA-related files under src/attention/cuda and updating the build system (CMakeLists.txt), the change enhances build clarity, module separation, and accelerates future CUDA-specific work. This minimal-risk refactor reduces maintenance overhead and positions the project for targeted performance optimizations in the CUDA path.
In July 2025, completed a focused codebase refactor in pytorch/FBGEMM to improve CUDA attention module organization. By moving GQA split-K CUDA-related files under src/attention/cuda and updating the build system (CMakeLists.txt), the change enhances build clarity, module separation, and accelerates future CUDA-specific work. This minimal-risk refactor reduces maintenance overhead and positions the project for targeted performance optimizations in the CUDA path.
June 2025 monthly summary for pytorch/FBGEMM: Delivered Prefetch Pipeline Support in bounds_check_indices kernel (v2) with reduced grid dimensions when prefetching is active and ensured compatibility with embedding memory offloading. Commit 9bd08928b43fcb1b66a2826a02719c69c99b16a6. Impact includes improved throughput for embedding workloads, reduced memory traffic, and better scalability for offloaded embeddings—supporting larger models and more efficient inference/training.
June 2025 monthly summary for pytorch/FBGEMM: Delivered Prefetch Pipeline Support in bounds_check_indices kernel (v2) with reduced grid dimensions when prefetching is active and ensured compatibility with embedding memory offloading. Commit 9bd08928b43fcb1b66a2826a02719c69c99b16a6. Impact includes improved throughput for embedding workloads, reduced memory traffic, and better scalability for offloaded embeddings—supporting larger models and more efficient inference/training.
May 2025 monthly summary for pytorch/FBGEMM: Delivered platform-aware improvements to the bounds_check_indices operator with refactoring for maintainability, ROCm compatibility enforcement (version 2), and refined version selection logic, strengthening cross-platform stability and readiness for broader deployment.
May 2025 monthly summary for pytorch/FBGEMM: Delivered platform-aware improvements to the bounds_check_indices operator with refactoring for maintainability, ROCm compatibility enforcement (version 2), and refined version selection logic, strengthening cross-platform stability and readiness for broader deployment.
April 2025 monthly summary for pytorch/FBGEMM focused on safety, portability, and reliability improvements across AI inference paths. Key outcomes include delivering BoundsCheck Indices v2 on ROCm with tests, mode validation, and prefetch support; hardening TBE kernels with bound checks, memory alignment, and contiguous data guarantees; and improving cross-arch kernel compatibility and RNG state handling. Reliability enhancements reduce CI noise and NaN propagation in embeddings. Business value is improved runtime safety, portability across AMD/NVIDIA, faster debugging, and more stable production workloads.
April 2025 monthly summary for pytorch/FBGEMM focused on safety, portability, and reliability improvements across AI inference paths. Key outcomes include delivering BoundsCheck Indices v2 on ROCm with tests, mode validation, and prefetch support; hardening TBE kernels with bound checks, memory alignment, and contiguous data guarantees; and improving cross-arch kernel compatibility and RNG state handling. Reliability enhancements reduce CI noise and NaN propagation in embeddings. Business value is improved runtime safety, portability across AMD/NVIDIA, faster debugging, and more stable production workloads.
March 2025: Stability and correctness improvements in pytorch/FBGEMM's TBE stack. The primary focus was eliminating race conditions and preventing indexing-related overflows to improve reliability, data integrity, and scalability of the TBE inference and gradient computations. Delivered targeted fixes with concrete commits that reduce data corruption risks and enable safe operation on larger embeddings in production workloads.
March 2025: Stability and correctness improvements in pytorch/FBGEMM's TBE stack. The primary focus was eliminating race conditions and preventing indexing-related overflows to improve reliability, data integrity, and scalability of the TBE inference and gradient computations. Delivered targeted fixes with concrete commits that reduce data corruption risks and enable safe operation on larger embeddings in production workloads.
January 2025 performance/dev summary for pytorch/FBGEMM. Key features delivered: TBE Benchmark Enhancements enabling input batch reuse with a --num-requests option and accuracy improvements by moving index/offset conversions outside the profiling region. Major bugs fixed: none reported this month. Overall impact: more scalable and reliable benchmarking, enabling faster validation of performance across configurations and reproducibility of results. Technologies/skills demonstrated: C++ benchmarking harness development, profiling-aware refactoring, performance measurement accuracy, and clean commit hygiene.
January 2025 performance/dev summary for pytorch/FBGEMM. Key features delivered: TBE Benchmark Enhancements enabling input batch reuse with a --num-requests option and accuracy improvements by moving index/offset conversions outside the profiling region. Major bugs fixed: none reported this month. Overall impact: more scalable and reliable benchmarking, enabling faster validation of performance across configurations and reproducibility of results. Technologies/skills demonstrated: C++ benchmarking harness development, profiling-aware refactoring, performance measurement accuracy, and clean commit hygiene.
December 2024 performance summary: Delivered reliability, performance, and maintainability improvements across FBGEMM and TorchRec, with a strong focus on kernel robustness, scalable indexing, and testing. The month included dynamic launch configuration improvements for pooled sparse features, occupancy-driven refinements for VBE bounds checking, 64-bit gradient indexing support in SplitOptimizer, and expanded validation through a generate_vbe_metadata test suite, along with a fix to prevent grid size overflow in 3D grid mappings. These efforts reduce runtime failures, enable larger-scale workloads, and improve test confidence, contributing to more stable production deployments and faster feature throughput.
December 2024 performance summary: Delivered reliability, performance, and maintainability improvements across FBGEMM and TorchRec, with a strong focus on kernel robustness, scalable indexing, and testing. The month included dynamic launch configuration improvements for pooled sparse features, occupancy-driven refinements for VBE bounds checking, 64-bit gradient indexing support in SplitOptimizer, and expanded validation through a generate_vbe_metadata test suite, along with a fix to prevent grid size overflow in 3D grid mappings. These efforts reduce runtime failures, enable larger-scale workloads, and improve test confidence, contributing to more stable production deployments and faster feature throughput.
November 2024: Delivered performance- and reliability-focused updates to pytorch/FBGEMM. Implemented a performance-optimized Bounds Checking Kernel (v2) with a controlled rollout via a feature gate, including grid-size and thread-block optimizations and VBE-specific launch enhancements. Refactored to support v1/v2 with feature gating for safe deployment. Fixed critical synchronization issue by ensuring iter_cpu runs on CPU to prevent incorrect GPU transfers. Strengthened memory checking for split optimizers through standardized tensor accessors and robust kernel argument construction. These changes enhance throughput of bounds checks, reduce synchronization risks, and improve memory-check reliability, contributing to safer, more scalable production workloads and stronger maintainability.
November 2024: Delivered performance- and reliability-focused updates to pytorch/FBGEMM. Implemented a performance-optimized Bounds Checking Kernel (v2) with a controlled rollout via a feature gate, including grid-size and thread-block optimizations and VBE-specific launch enhancements. Refactored to support v1/v2 with feature gating for safe deployment. Fixed critical synchronization issue by ensuring iter_cpu runs on CPU to prevent incorrect GPU transfers. Strengthened memory checking for split optimizers through standardized tensor accessors and robust kernel argument construction. These changes enhance throughput of bounds checks, reduce synchronization risks, and improve memory-check reliability, contributing to safer, more scalable production workloads and stronger maintainability.
Month 2024-10 — FBGEMM performance instrumentation and embedding-related improvements focused on observability, correctness, and benchmarking readiness. Key initiatives delivered in pytorch/FBGEMM: - Kineto tracing integration for FBGEMM embeddings: Added Tensor Block Encoding (TBE) annotation and trace recording in forward/backward passes, enabling detailed performance analysis via Kineto, JustKnob, or environment-variable controls. This enhances observability into embedding ops and helps target optimizations. - Embedding path correctness improvements: Fixed the PackedTensorAccessor usage for batch_index_select output_offsets and total_L_offsets to improve correctness and reliability of the embedding forward pass. - Benchmarking enhancements: Expanded the bounds_check_indices benchmark with Variable Batch Embeddings (VBE) support and an option to export execution traces for deeper performance insights, enabling more realistic and tunable benchmarking scenarios. Overall impact: Improved observability, reliability, and benchmarking capabilities for embedding workloads, facilitating faster performance tuning and data-driven optimization. Demonstrated technologies/skills include Kineto tracing integration, Tensor Block Encoding, JustKnob-assisted analysis, environmental tracing controls, VBE support, and benchmark instrumentation.
Month 2024-10 — FBGEMM performance instrumentation and embedding-related improvements focused on observability, correctness, and benchmarking readiness. Key initiatives delivered in pytorch/FBGEMM: - Kineto tracing integration for FBGEMM embeddings: Added Tensor Block Encoding (TBE) annotation and trace recording in forward/backward passes, enabling detailed performance analysis via Kineto, JustKnob, or environment-variable controls. This enhances observability into embedding ops and helps target optimizations. - Embedding path correctness improvements: Fixed the PackedTensorAccessor usage for batch_index_select output_offsets and total_L_offsets to improve correctness and reliability of the embedding forward pass. - Benchmarking enhancements: Expanded the bounds_check_indices benchmark with Variable Batch Embeddings (VBE) support and an option to export execution traces for deeper performance insights, enabling more realistic and tunable benchmarking scenarios. Overall impact: Improved observability, reliability, and benchmarking capabilities for embedding workloads, facilitating faster performance tuning and data-driven optimization. Demonstrated technologies/skills include Kineto tracing integration, Tensor Block Encoding, JustKnob-assisted analysis, environmental tracing controls, VBE support, and benchmark instrumentation.
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