``` #include <sys/epoll.h> int epfd = epoll_create1(0); /* rax=291，建内核就绪队列 */ struct epoll_event ev; ev.events = EPOLLIN; ev.data.fd = sockfd; epoll_ctl(epfd, EPOLL_CTL_ADD, sockfd, &ev); /* rax=233，注册关注项 */ struct epoll_event ready[64]; int n = epoll_wait(epfd, ready, 64, 1000); /* rax=232，等待最多1秒 */ for (int i = 0; i < n; i++) { /* 仅遍历n个就绪项，不扫描全部描述符 */ } ``` 链路：`epoll_create1()` → glibc 置 `rax=291`，陷入后内核分配 eventpoll 结构并返回描述符。`epoll_ctl()` 置 `rax=233`，`rdi=epfd`、`rsi=op`、`