Re: using more than 2 GB as a ram disk

H. Peter Anvin (hpa@transmeta.com)
Wed, 3 Feb 1999 17:46:44 -0800 (PST)


>
> The Alpha only has about 43 address bits; is the Alpha not 64-bit?
>

The Alpha can be extended to 64 bits **WITHOUT SOFTWARE IMPACT**.

> > you either store pointers in a non-flat format or normalize
> > them every time;
>
> Yes, exactly. For userspace, this is hidden by the compiler.
>
> > once (or if) Intel adds more adds more address bits than 36
> > you're hosed again.
>
> At that point I expect a fix for the virtual address space too.
> If not, you can extend the hack a bit. Don't use Electric Fence.

... and your old binaries are worthless.

> > Not to mention the cost to load segments for every reference.
>
> The compiler may be able to reduce it a bit. Even if not, I have
> yet to see another proposal that gets the job done on ia32.
>
> In other words: I did it! I claim bragging rights to this abomination.

These kinds of proposals have been around for a long time (I remember
seeing them back in the i386 days, using external logic.) They're
just as useless now as then.

-hpa

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