Sharing Linux kernel-related cutting-edge technology, technical articles, technical news, and curated tutorials
Arm’s 2025 launch replaces the X and A series with the C1 CPU family and G1 GPU, introducing Armv9.3‑A cores, new branding for different markets, a Lumex CSS platform, and the SME2 matrix extension that together boost performance, cut power consumption, and dramatically improve AI capabilities.
This article dissects Android’s task scheduling challenges by correcting misconceptions about virtual runtime, detailing load‑normalization using WAL‑T, deriving a frequency‑aware task_load formula, exposing the chicken‑egg problem between load and frequency, and exploring priority inversion and rtmutex as a mitigation strategy.
This article examines the challenges of Energy Aware Scheduling on big‑LITTLE CPUs, detailing how frequency prediction, power calculation, cache hierarchy, out‑of‑order execution, and branch prediction affect task placement decisions, and why the resulting models often remain inaccurate and unreliable.
This article explains Linux's CFS scheduler mechanics, including the impact of priority, virtual runtime, event‑driven scheduling, the differences between PELT and WALT load‑tracking algorithms, and the complexities introduced by big‑LITTLE architectures on task placement, throughput, and latency.
This article explains why many Android threads appear idle despite free CPU cycles, by dissecting Linux's five scheduler classes, the distinction between RT and fair scheduling, the role of virtual runtime and weight, and how cgroup cpu.shares can reshape resource distribution, supported by concrete systrace experiments.
This article explains eBPF from a developer's perspective, covering the eBPF virtual machine, instruction encoding, bytecode generation with LLVM/Clang, loading via the bpf() syscall, verifier rules, execution flow, JIT compilation, and how Android builds and packages eBPF programs.
Adaptive Bitrate (ABR) streaming dynamically selects among multiple video representations using protocols like HLS, DASH, and CMAF, leveraging bandwidth predictions and buffer metrics to balance quality and re‑buffering, while evolving through hybrid, buffer‑based, rate‑based, and machine‑learning algorithms for optimal user experience.
This article explains how Digital Rights Management protects modern streaming content, outlines the industry chain, compares hardware‑level L1 and software‑level L3 security, and details Google Widevine's architecture, ecosystem, and key provisioning methods.
Weaver enhances Android’s password‑unlock system by moving rate‑limiting and secret storage into a Secure Element, protecting the authentication secret when the device is off and throttling repeated guesses with hardware timers, thereby hardening GateKeeper/KeyMint against offline brute‑force attacks despite added OMAPI latency.
The article explains how mobile device manufacturers can balance high frame‑rate gaming performance with reduced power draw by quantifying FPS metrics, applying temperature‑limited frame rates, using PM QoS and uclamp frequency scaling, implementing boost logic, and tailoring thread scheduling, emphasizing close collaboration with developers and silicon vendors.
