Mach's in-kernel scheduling

[Igor Khavkine]

Hi,

It is my understanding that Mach supports "in-kernel" threads,
i.e. threads that run concurrently in the kernel, not being visible
in userspace.

The first kernel thread, after it does all the initialization and starts
userspace initialization, runs vm_pageout() to become the garbage
collection daemon.

Turns out that zones are susceptible to garbage collection. However,
I'm really clueless about Mach's way of scheduling these "in-kernel"
threads. When does this GC thread actually get to run, can it run
concurrently while a system call is executed, or does it need
a yield statement somewhere?

Thanks.

Igor