A professional Linux technology community and learning platform covering the kernel, memory management, process management, file system and I/O, performance tuning, device drivers, virtualization, and cloud computing.
This article explains how layer‑3 priority flow control uses the DSCP field to map VLAN CoS classes to lossless queues, details the configuration steps for PFC, ETS, and DCBX, and describes congestion scenarios and detection metrics in fused Ethernet data‑center networks.
This section analytically derives the headroom size for loss‑less Ethernet links using IEEE 802.1Qbb priority flow control, detailing worst‑case delays, interface and cable latency, buffer cell sizing, Cisco Nexus configuration examples, and a comparison with Fibre Channel B2B primitives.
This article explains Ethernet flow‑control mechanisms (LLFC and PFC), how pause frames and their quanta are calculated, the role of pause and resume thresholds (XOFF/XON), headroom and footroom concepts, buffer‑queue management, and provides Cisco Nexus configuration examples for lossless storage networks.
The talk examines the challenges of using standard Linux TCP for high‑performance data‑center workloads, explores how RDMA can provide zero‑copy and asynchronous kernel bypass, and presents experimental results from an FPGA‑based prototype that approaches 800 Gbps packet rates while highlighting congestion‑control and CPU‑utilization trade‑offs.
The article categorizes Linux kernel synchronization primitives by their target—critical sections, CPUs, memory, or cache—detailing atomic variables, spinlocks, semaphores, mutexes, read‑write locks, preemption, RCU, and memory barriers, explaining their mechanisms, trade‑offs, and typical kernel usage examples.
The article surveys the evolution of POSIX abstractions from the 1970s to the present, explains why hardware trends and modern workloads expose limitations of the CPU‑centric model, and argues that a new set of higher‑level interfaces is needed for future systems.
This article explains the ARMv8 virtualization architecture, covering its core characteristics, exception levels, Stage‑2 address translation, MMIO emulation, SMMU handling, trap‑and‑emulate mechanisms, virtual interrupts, generic timer virtualization, host extensions, nested virtualization, and the associated performance overheads.
The article details Minsheng Bank's step‑by‑step journey from traditional network monitoring to a full‑stack, zero‑intrusion observability platform built with DeepFlow, vTap, distributed data collection, and eBPF, illustrating concrete case studies and future plans for expanding business‑level monitoring.
The article compares spin_lock, rwlock, seqlock and RCU for protecting a shared kernel resource in a multi‑core embedded system, explains how RCU enables lock‑free reads, discusses the challenges of safe deletion, and outlines the RCU read‑copy‑update workflow.
The article investigates why BPF LSM programs fail to load on aarch64 kernels, uses ftrace‑based tools such as bpftrace and trace‑cmd to trace kernel execution, discovers missing arch_prepare_bpf_trampoline support in 5.15 and 6.1, and shows that a patch merged into the mainline kernel restores functionality for upcoming releases.
