| Summary: This text is a tutorial about eBPF scheduler, focusing on the sched_ext scheduler in the Linux kernel version 6.12. The tutorial explains the architecture of sched_ext, how to use BPF programs to define scheduling behavior, and guides the reader in compiling and running an example. The sched_ext scheduler is a flexible and customizable scheduler that allows the implementation of any scheduling algorithm on top of it. Its key features include flexible scheduling algorithms, dynamic CPU grouping, runtime control, system integrity, and debug support. The tutorial covers the core of the sched_ext tutorial, which is the sched_ext scheduler class. Unlike traditional schedulers, sched_ext allows scheduling behavior to be defined dynamically through a set of BPF programs, making it highly adaptable and customizable. This means that any scheduling algorithm can be implemented on sched_ext to meet specific requirements. The tutorial then introduces scx_simple, a minimal example of a sched_ext scheduler. It is designed to be simple and easy to understand, and provides a foundation for more complex scheduling policies. Scx_simple can run in two modes: global vtime mode and FIFO mode. Global vtime mode sorts tasks based on their virtual time priority, ensuring fairness between different workloads. FIFO mode, based on a simple queue, executes tasks in the order they arrive. The tutorial covers the use cases and applicability of scx_simple, and provides code analysis in both the kernel and user space. In the kernel space, the tutorial shows the complete code segments and explains their functions. In the user space, the tutorial covers the implementation of the read_stats function, which collects and reports statistics on the local and global queues. The tutorial concludes by summarizing the importance of sched_ext and eBPF in creating and managing advanced scheduling policies. The tutorial provides references to the sched_ext repository, Linux kernel documentation, eBPF official documentation, and the libbpf documentation.本文是关于 eBPF 调度器的教程，重点介绍 Linux 内核 6.12 版本中的 sched_ext 调度器。本教程介绍了 sched_ext 的架构，如何使用 BPF 程序定义调度行为，并指导读者编译和运行示例。sched_ext 调度程序是一个灵活且可自定义的调度程序，允许在其上实施任何调度算法。其主要功能包括灵活的调度算法、动态 CPU 分组、运行时控制、系统完整性和调试支持。本教程涵盖了 sched_ext 教程的核心，即 sched_ext 计划程序类。与传统调度程序不同，sched_ext 允许通过一组 BPF 程序动态定义调度行为，使其具有高度的适应性和可定制性。这意味着可以在 sched_ext 上实施任何调度算法以满足特定要求。然后，本教程介绍了 scx_simple，这是 sched_ext 计划程序的最小示例。它设计为简单易懂，并为更复杂的计划策略提供了基础。Scx_simple 可以在两种模式下运行：全局 vtime 模式和 FIFO 模式。全局 vtime 模式根据任务的虚拟时间优先级对任务进行排序，从而确保不同工作负载之间的公平性。FIFO 模式基于简单队列，按照任务到达的顺序执行任务。本教程涵盖了 scx_simple 的使用案例和适用性，并提供了内核和用户空间中的代码分析。在内核领域，本教程展示了完整的代码段并解释了它们的功能。在用户空间中，本教程介绍了 read_stats 函数的实现，该功能收集并报告本地和全局队列的统计信息。 本教程最后总结了 sched_ext 和 eBPF 在创建和管理高级调度策略中的重要性。本教程提供了 sched_ext 仓库、Linux 内核文档、eBPF 官方文档和 libbpf 文档的参考。 |