[PATCH] Implement support for mem command line parameter

Bernhard Walle bwalle at suse.de
Tue Jun 10 15:31:58 EDT 2008

* Vivek Goyal <vgoyal at redhat.com> [2008-06-09 23:00]:
> > Right. I just checked with (openSUSE 10.3 kernel), and
> > 
> >   - i386: /proc/iomem contains full memory
> >   - x86_64: /proc/iomem contains truncated memory
> > 
> > After the x86 merge, x86_64 now has the behaviour of i386.
> >   
> Cool. Now atleast behavior across x86 and x86_64 is same.

After studying the code, well, that was wrong. I tested again:

 - i386: /proc/iomem contains truncated memory
 - x86_64: /proc/iomem contains full memroy

And after the merge, it stays the same, i.e. /proc/iomem in i386 is

Sorry for the confusion. :-|

The question is: Is that "accidentally" or by design. The file

        [X86-32] Use together with memmap= to avoid physical
        address space collisions. Without memmap= PCI devices
        could be placed at addresses belonging to unused RAM.

implies that it's "by design".

(And EFI code might be different again. However, I have no non-IA64
EFI machine to test.)

Bernhard Walle, SUSE LINUX Products GmbH, Architecture Development

More information about the kexec mailing list