Likwid is a comprehensive performance monitoring and benchmarking tool suite for HPC environments. It provides command-line tools (likwid-perfctr, likwid-pin, likwid-bench, likwid-powermeter, likwid-topology, etc.) and a C/Fortran/Lua library for reading hardware performance counters, managing CPU/GPU topology, controlling system features (turbo, prefetchers, RAPL power limits), and pinning threads. The architecture is modular: a core C library (liblikwid) handles low-level hardware access via MSR, PCI, MMIO, or a privileged daemon, while Lua scripts provide user-facing interfaces. External dependencies (Lua, hwloc, GOTCHA, cwisstable) are bundled. The codebase supports x86, ARM, POWER, and GPU (NVIDIA, AMD) architectures with per-architecture performance counter definitions. It is primarily an application tool, though its extensive hardware counter definitions and benchmark infrastructure also serve research purposes.
NootedRed is a macOS kernel extension (Lilu plugin) that enables AMD integrated GPUs (Raven, Picasso, Renoir, Green Sardine) on macOS by patching Apple's proprietary AMD GPU drivers. It operates through binary patching, runtime vtable manipulation, and firmware injection to spoof GPU identity, fix display/audio/backlight issues, and provide hardware acceleration. The codebase is a intricate reverse-engineering effort, with hardcoded version-specific offsets and byte patterns, but it is structured into modular components such as display controllers, hardware library patches, and a reusable patching toolkit (PenguinWizardry). While the project is highly specialized and fragile due to its reliance on exact binary layouts, it demonstrates advanced kernel programming and reverse engineering skills. The repository is actively maintained for current macOS versions and includes a CI pipeline with static analysis.
This repository implements AMD's MxGPU virtualization solution, providing SR-IOV support for AMD GPUs (MI200, MI300, Navi32). It consists of a kernel module (GIM) that manages virtual functions, a core library (libgv) for hardware abstraction and RAS, and a user-space system management interface (SMI) with CLI and Python bindings. The architecture is layered: the kernel driver (gim/) communicates with hardware and exposes IOCTLs; libgv/ provides hardware-specific implementations via function pointer tables; smi-lib/ provides a unified API for monitoring, partitioning, RAS, and NIC management. Key entry points include the GIM kernel module (gim/gim_shim/gim_drv.c), the SMI CLI (smi-lib/cli/cpp/src/smi_cli_main.cpp), and the SMI library (smi-lib/src/amdsmi.c). Data flows involve PF-VF mailbox communication, RAS error logging via CPER, and telemetry collection through SMU firmware interfaces. External dependencies include Linux kernel headers, DKMS, and optional NIC libraries. The codebase is large and professionally structured, with extensive hardware abstraction layers, unit tests, and packaging scripts, though it carries maintenance risks from ASIC-specific duplication and embedded firmware blobs.