Questions about Context Switch in VM

Blogging is often about opinions, solutions, and feedback. But, what if I have questions?

While watching the MySQL video, it surprised me when Stewart Smith said the storage note daemon runs on a single thread. They have its own context switching that is more efficient than using the thread from the OS.

Talking about context switching doesn't work best for some situation, I think of another situation: when the OS runs inside VM like VMWare. Even when the primary OS is mainly idle, the guest VM is still not very responsive.

Would it be because we have too many context switches happening in the primary OS, and it makes context switch in the guest OS happens in bad time?

What VM system is doing to help this situation? Will we have a configuration flag for Linux (or other OS) to let the OS context switch differently when it is a guess? (Of course, the guest machine is not supposed to know it is guest, unless you config it as such.)

Tag: virtualization, concurrency