[issue1300] vkernel suspends execution when showing ddb prompt

[Matthew Dillon]

:whenever the MP vkernel breaks to the debugger prompt, it will suspend
:execution.  To reach the debugger, you will have to put it to foreground ma=
:nually.
:
:The reason for this is this line in platform/vkernel/i386/mp.c:
:
:                if (pthread_kill(ap_tids[n], SIGSTOP) !=3D 0)
:
:as specified by POSIX, sending a SIGSTOP signal to any thread of a process =
:will
:stop the complete process.
:
:The solutions probably would need some other means of thread communication =
:than
:a mere stop signal.

    Ah, yah, it's been doing that for a while.  I'll fix it.  I have to
    have the vkernel use a dedicated signal and sigsuspend() loop.  It's
    fairly straight-forward.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>