🚀 go-pugleaf

In article <4643@sugar.hackercorp.com> peter@sugar.hackercorp.com (Peter da Silva) writes:
>In article <14060@grebyn.com> ckp@grebyn.UUCP (Checkpoint Technologies) writes:
>> Laugh if you like. In VAX/VMS, every part of a process is virtual
>> memory, including any IO buffering. The IO system takes care of ensuring
>> that such pages are resident and locked for the duration of a DMA IO
>> transfer.
>
>Too bad it doesn't go one step more and make the files *really* mapped, so
>they "page" back into the real file they're supposed to come from.
>
>Really, I don't see the point of writing stuff to one part of the disk when
>you're just going to have to read it in again and write it to another part
>of the disk later on.
>
>This was a feature of Multics some, oh, 20 years ago now. ALL files were mapped
>into memory... paged to and from the physical disk on demand.

If you had a fast disk that you were using for your virtual memory 
swapping and a somewhat slower disk you were using for your
main storage it would make sense to move it from the storage disk to
the virtual memory disk.  You might, for example, have a large optical
WORM type drive with lots of data on it and a smaller, but faster hard
drive that you used just for VM.  You also wouldn't want to map the
buffers for a floppy drive back on to the floppy that they came from.




Stupid extra lines for rn.



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|  Mark Waggoner   (408) 721-6306           waggoner@dtg.nsc.com     |
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