Re: [uml-user] UML Strange Hang

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

jb...@ci... said:
> Basically what happens is when starting a uml machine every once in a
> while it hangs on boot-up until I hit any key on the keyboard at which
> point it continues to boot, but may or may not require me hitting the
> keyboard until the login prompt appears.  It seems very easy for me to
> recreate if I crash the uml machine because it will consistently hang
> like that on fsck'ing the partitions.

I've had one other report of this, but haven't seen it myself, which sort
of hampers my ability to track it down.

Basically what is happening is that a disk interrupt (a SIGIO from a 
particular file descriptor) is be delivered to a process which is asleep
(or just about to go to sleep).  Thus, that interrupt is temporarily lost
and the IO request it represents isn't handled, so the process that was
waiting for the IO (e.g. fsck) sleeps.  Hitting keys will cause the common
SIGIO handler to run, and it will notice the waiting disk IO as well as
the keyboard input.

To help track it down, a good start would be to try versions of UML until
you find one that doesn't do it.

				Jeff