Re: [uml-user] Running latest UML under 2.2.20

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

a.p...@dn... said:
> One thing it doesn't explain is why some machines have a 2G/2G - is
> this a hardware thing or dependent upon the Linux version ? 

It's not hardware dependent.  Some machines are used in such a way that
they run short of kernel VM in their 1G area, so Linux can be rebuilt to
provide another 1G to give them some more breathing room.

> Do you
> know of a relatively straightforward way to determine if you've got 2G/
> 2G ?

cat /proc/$$/maps

On a 3G/1G kernel, the last line ends in c0000000:

bfffd000-c0000000 rwxp ffffe000 00:00 0

On a 2G/2G kernel, it will end in 80000000.

> tandem@freeze:uml 503# ./linux-2.4.9-6_2g  
> Mapping memory: Invalid argument 

Drat, I thought I had you on that one...

I guess it's back to figuring out what's happening.  gdb UML, set a breakpoint
in main, start stepping, and see how far you get.  And if it doesn't get to
main, then something is strange with the host.

Also, even though linux-2.4.9-6_2g isn't working either, is seems to be
getting further.  It's bombing out in setup_memory, so try putting a breakpoint
on that perror and see what the arguments to mmap are and what *region is.

Remember the > 256 space string as the first argument, too.

				Jeff