Tunnel encapsulation is real work, but not all real work can be mapped to tunnel encapsulation.
The point of all that work to context switch into processes to handle small amounts of network I/O is that very often THE CORRECT SOFTWARE ARCHITECTURE is for multiple address-space-separated processes to be doing small amounts of network I/O. That I/O "means something" to a larger data model being implemented by the software.
It's true that for some tasks that "look like routing" there's no point to having that kind of external data model. The packets are the data being operated on. So there's little value in process separation and you might as well DMA them all streamwise into a single process to do it. And that's great stuff, but AFAICT it's really not what the linked article is about.
Ultimately, all those packets are going to end up in conventional processes, because that's where conventional processing needs to happen. There are very good reasons why we like our page-protected address space separation in this world!
The point of all that work to context switch into processes to handle small amounts of network I/O is that very often THE CORRECT SOFTWARE ARCHITECTURE is for multiple address-space-separated processes to be doing small amounts of network I/O. That I/O "means something" to a larger data model being implemented by the software.
It's true that for some tasks that "look like routing" there's no point to having that kind of external data model. The packets are the data being operated on. So there's little value in process separation and you might as well DMA them all streamwise into a single process to do it. And that's great stuff, but AFAICT it's really not what the linked article is about.
Ultimately, all those packets are going to end up in conventional processes, because that's where conventional processing needs to happen. There are very good reasons why we like our page-protected address space separation in this world!