Re: zap_page_range in a module

Benjamin LaHaise (bcrl@redhat.com)
Fri, 14 Dec 2001 21:31:42 -0500

On Fri, Dec 14, 2001 at 06:10:52PM -0800, Sottek, Matthew J wrote:
> >The vm does zap_page_range for you if you're implementing an
> >mmap operation,
>
> It only does zap_page_range() when the memory map is being
> removed right?

Right.

> I have a 64k sliding "window" into a 1MB region. You can only access
> 64k at a time then you have to switch the "bank" to access the next
> 64k. Address 0xa0000-0xaffff is the 64k window. The actual 1MB of
> memory is above the top of memory and not directly addressable by the
> CPU, you have to go through the banks.

Stop right there. You can't do that. The code will deadlock on page
faults for certain usage patterns. It's slow, inefficient and a waste
of effort.

-ben

-- 
Fish.
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