Re: [uml-devel] Using UML to execute Linux device drivers under other OSs

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

ad...@do... said:
> I never said scan.  When an int 80 occurs, check to see if the source
> of the call is an unmodified executable page.  If so, then modify it
> with a faster call, that doesn't require using PTRACE to intercept int
> 80 calls.

Oh, OK.  Except it won't be any faster.  The tracing thread has to be there
in order to do the first interception of each system call.  Whatever you
replace the int 80 with has to generate a signal.  Given the current
semantics of ptrace, which don't let you ignore anything, that signal will
be seen by the tracing thread and passed along by it to the running thread.

So, this won't be saving any context switches.  To do that, you need to 
completely eliminate the tracing thread.

				Jeff