Re: Kernel virtual memory?

Jochen Karrer (karrer@wpfd25.physik.uni-wuerzburg.de)
Thu, 7 Aug 1997 17:58:04 +0200 (MET DST)


Hi,

> Could kernel use virtual memory hardware to make non-linear chunks of
> memory to look linear? It seems to me that it could solve the problems
> with memory fragmentation and DMA memory allocation.

The memory management is done in the CPU, so only the CPU sees
this virtual address. PCI-BUS- and ISA-Address is on intel architecture
the same address like the physical address.

>
> DMA memory could be allocated by moving allocated blocks away from the
> lower 16MB, and other parts of kernel could be made happy by changing the
> page tables accordingly.
>
> So, is this possible/feasible/too ugly to implement?
Not possible.

Jochen

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