OPPO Kernel Craftsman

May 23, 2025 · Fundamentals

Why Android Threads Stall: Inside Linux CFS, RT, Fair Scheduling and cgroup Limits

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.