程序性能随使用时长下降：Rust 程序变慢与 LLM 重写效果减弱
Program Performance Degrades with Usage
一位开发者发现其 Rust 命令行程序在一天中会逐渐变慢，基准测试结果无论如何都变差，原因很可能是 Linux 系统整体资源占用，而非程序本身。由于程序使用大块 mmap，一旦进入这一状态，基准测试基本等同于在测操作系统，继续用 Rust 优化代码已不值得，因此他将不再重视基于 LLM 的 Rust 重写，因为其已无法带来可测量的差异。
Oct 12, 2026
One thing I have noticed recently, when trying to improve my Rust program, is that it tends to become progressively slower over the course of a day. If I am trying to benchmark something, it seems like no matter what I do, it becomes slower.
It seems likely that given my program is not running continuously, and is run as a command-line program, the slowdown is due to general resource usage on the computer. The program uses a large mmap so this relies on many sub-systems in Linux.
In any case, once a program reaches this point, a benchmark of the program mostly is a benchmark of the OS. Further code optimization in Rust is not worthwhile. So to put it bluntly, I will de-emphasize my LLM-based Rust rewrites, as they are no longer making a measurable difference.
来源：Hacker News · dotnetperls.com