Re: [uml-user] uml stuck on "Locating the top of the address space"

[Joakim A. <jo...@ar...>]

Yes, the CPU is pegged while this is happening. I've left it for an hour
with no results.

I looked at that code and couldn't really see a good reason for it to block
forever, except if the address space was so large it took a long time to
get through.

The host kernel is 2.6.32-220.4.1.el6.i686 #1 SMP

This is an Amazon EC2 instance, and I just found one hilarious workaround
for this. If I remove the "user-data" from the instance, UML starts working
again. User-data is a string that EC2 makes available to the running
instance as the response of an http request to a fake ip.



On Sun, Feb 12, 2012 at 3:08 PM, richard -rw- weinberger <
ric...@gm...> wrote:

> On Sun, Feb 12, 2012 at 9:23 PM, Joakim Arfvidsson
> <jo...@ar...> wrote:
> > It finds the bottom address, but is stuck forever on top address.
> >
> > This is all on an Amazon EC2 instance (so it's running within some Xen
> vm).
> > Host is running 32 bit RedHat.
> >
> > Command line and results:
> >
> >> ./kernel32-3.2.5 -v ubda=/tmp/cow4:Debian-Squeeze-x86-root_fs mem=256m
> > Locating the bottom of the address space ... 0x0
> > Locating the top of the address space ...
> >
> > Freaky thing is that this was working fine on the same machine yesterday,
> > but started failing today. Now fails consistently, never getting farther
> > than here. I can't think of anything I changed about the setup.
> >
> > Any help appreciated!
> >
>
> Is the UML process consuming CPU time at this point?
> The calculation happens here:
> arch/x86/um/os-Linux/task_size.c
>
> Which host kernel are you using?
>
> --
> Thanks,
> //richard
>