Re: [User-mode-linux-devel] implementation questions

[Jeff D. <jd...@ka...>]

> I have some questions about the implementation of uml:
> 1. Why is TIMER_VIRTUAL used instead of TIMER_REAL?

Because this is a virtual machine, and so it runs on virtual time...

Also, this makes better guarantees about the regularity of the timer interrupt 
on a loaded system than TIMER_REAL would.  It also provides more consistent 
BogoMips :-)

> 2. Why is SIGVTALRM blocked during a SIGSEGV?

Because I wasn't sure whether the fault handler should be protected, so I did 
it to be safe.

> 3. Is the kernel protedted from user mode access, and if so, how?

No.

> (Perhaps the answers could be documented somewhere, in case someone
> else is interested in the implementation.) 

This is it, unless someone else feels like writing this stuff down...

				Jeff