Popping Kernels

Dear KV,

I have been working at the same company for more than a decade, and we build what you can think of as an appliance—basically a powerful server meant to do a single job, instead of operating as a general-purpose system. When we first started building this system, nearly all the functionality we implemented was added to the operating system kernel as extensions and kernel modules. We were a small team and capable C programmers, and we felt that structuring the system this way gave us more control over the system generally, as well as significant performance gains since we did not have to copy memory between the kernel and user space to get work done.