Re: Bug: Discontigmem virt_to_page() [Alpha,ARM,Mips64?]

Russell King (rmk@arm.linux.org.uk)
Mon, 6 May 2002 01:55:05 +0100

On Mon, May 06, 2002 at 01:54:52AM +0200, Daniel Phillips wrote:
> I must be guilty of not explaining clearly. Suppose you have the following
> physical memory map:
>
> 0: 128 MB
> 8000,0000: 128 MB
> 1,0000,0000: 128 MB
> 1,8000,0000: 128 MB
> 2,0000,0000: 128 MB
> 2,8000,0000: 128 MB
> 3,0000,0000: 128 MB
> 3,8000,0000: 128 MB
>
> The total is 1 GB of installed ram. Yet the kernel's 1G virtual space,
> can only handle 128 MB of it.

I see no problem with the above with the existing discontigmem stuff.
discontigmem does *not* require a linear relationship between kernel
virtual and physical memory. I've been running kernels for a while
on such systems.

Which was the reason for my comment at the start of this thread:
| On ARM, however, we have cherry to add here. __va() may alias certain
| physical memory addresses to the same virtual memory address, which
| makes:

-- 
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html


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