Re: [kernel-reviewers] a small code review (2414483) Automated g4 rollback of changelist 2396062.

[Tim Hockin <thockin@google.com>]

On Wed, Apr 26, 2006 at 10:36:54AM -0700, Martin Bligh wrote:
> Tim Hockin wrote:
> >On Wed, Apr 26, 2006 at 10:12:14AM -0700, Ken Harrenstien wrote:
> >
> >>That doesn't work because IIRC it only reports the amount of memory
> >>the kernel has been told (eg via "mem=") to manage in a certain sense,
> >>not how much is actually physically available.
> >>
> >>The I2 netboot kernel would really REALLY like some exported /proc
> >>values that accurately report physical memory (if nothing else, the
> >>number of DIMMs and their sizes).  It has to figure this out in order
> >>to install the proper kernel with proper LILO command-line args.
> >
> >
> >The kernel can't really know how much memory is in the system without
> >getting chipset-specific.
> >
> >MTRR is a good way to hazard a guess, and will probably be right, but as
> >you indicated, BIOS vendors have historically been REALLY bad about
> >MTRRs.  Better now, but bad a few years ago.
> >
> >SMBIOS (on our boards) *does* accurately report the number of DIMMS and
> >their sizes (and more!).  But it only works on Google BIOS.
> 
> Are you saying our e820 maps and srat tables are wrong? that's a little
> worrying ...

e820 is fine, except there's not a good kernel interface to it.  Parsing
dmesg is *always* a last resort.

We don;t currently have SRAT. :)

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