Large mmio resources and 4G+ of RAM...

Eric W. Biederman ebiederman at
Tue Jun 1 10:17:00 CEST 2004

ron minnich <rminnich at> writes:

> just FYI, making BARS live above the 32-bit limit will break every single
> linux cluster here at LANL, and will also disable Plan 9.

Only for the hardware where the BARs move.  
> With BARS under the 32-bit limit, you can boot anything. With BARS above 
> that limit, you immediately limit what you can boot. 

Yes.  And largely I see that as a good thing.
> I think what really ought to happen is we fix linux early boot to do what
> we wanted in the beginning of this project 5 years ago: linux should do
> BAR optimization for the kernel that is running.

There are enough other bits you need to twiddle I don't think
you can implement that generically.
> In principle, I like your BAR fix, but setting up BARS that are optimized
> for 64-bit kernels should be a (normally disabled)  option.

For old clusters I agree that it should be normally disabled.
> I wonder if we can put BAR reallocation into a payload?

The amount of code should be just a handful of lines so I don't think
that will be necessary.  Especially since I have to go through a very
limited number of bridge BARs.


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