A different kind of Walter? :-)

[Sean Kelly]

Dan wrote:
> Sean Kelly Wrote:
>> Lionello Lunesu wrote:
>>> I don't care if there address changes, just as long as there's no data being 
>>> copied physically. I mean, a block of continuous memory might already be 
>>> all-over-the-place in physical memory. That's what I want: a VirtualRealloc 
>>> that returns the address of a new virtual memory block, but which is using 
>>> the same physical memory.. 'Free' array resizes, surely this is worth 
>>> something!
>> Hm, assuming there is nothing else of the page(s) but the data to move, 
>> it should be possible to do so without explicit copying.  I have no idea 
>> is VirtualAlloc can do this, but it's definitely possible.
> 
> Oh my!
> 
> On the x86, this sort of implementation would slaughter your performance, as you'd get massive numbers of cache and page misses.
> 
> You could theoretically implement a system on the x86 that would virtualize memory locations arbitrarily, but.... ewww...

Yeah.  I was thinking that the way to do this would be in the virtual 
memory manager.  When the pages are moved the page table is updated, etc.


Sean