Intel(R) Ethernet Controller I210 and other NICs provide the LaunchTime feature which enables frames to be transmitted at specific times. In Linux, this hardware feature is enabled through the SO_TXTIME sockopt and ETF qdisc.
曾看到一段这样的描述,但是网络上相关的资料太少了。尝试在内核源码中找相关线索,无果
按照我目前的理解,这个功能应该是内核通过 getsockopt / setsockopt API 暴露给用户态程序的。但是这对 TCP 传输来说似乎没有意义,适用场景大概是 UDP / ICMP / RAW socket 等传输