Re: kernel panic when using disable_mtrr_trim [was: Re: memory beyond4GB invisible to the system even though CONFIG_HIGHMEM64G=y]

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 29 Jan 2009 16:09:43 -0800
Andrew Morton <akpm@linux-foundation.org> wrote:

> On Tue, 20 Jan 2009 13:18:15 -0500
> "James Kirin" <james.kirin40@gmail.com> wrote:
> 
> > Hi Yinghai,
> > 
> > When I boot with "disable_mtrr_trim mem=4g", the system boots fine.
> > Then I changed that to
> > "disable_mtrr_trim mem=6g" and a kernel panic occurs:
> > 
> > [...] Freeing unused kernel memory: 296k freed
> > [...]  Write protecting the kernel text: 3040k
> > [...]  Write protecting the kernel read-only data: 1352k
> > [...]  khelper used greatest stack depth: 6724 byytes left
> > [...]  Kernel panic - not syncing: No init found. Try passing init=
> > option to kernel.
> > 
> > I can always reproduce this: all it takes it to boot from a rescue CD,
> > switch between "mem=4g"  and "mem=6g" in /etc/lilo.conf, run lilo and
> > reboot. If it is 4g, it boots fine; if it is 6g, a kernel panic
> > occurs. No other changes at all were made.
> > 
> > Same thing (kernel panic) occurs if mem=5g is used.
> > 
> > I am attaching the kernel config used when this happens.
> > 
> > Please let me know how I can help fix this. Does it somehow depend on
> > all those MTRR/etc memory-related options in the kernel configuration?
> > 
> 
> Did this get fixed?
> 

It seems that it was fixed.

The subject was rewritten, threading was broken and you weren't cc'ed. 
Handy!