Re: Memory intensive processes

Harald Koenig (koenig@tat.physik.uni-tuebingen.de)
Wed, 11 Dec 1996 20:21:45 +0100 (MET)

> > This is true. Also the act of READING zero-filled pages should not cause
> > a trap to the operating system. Many FFTs null-fill a lot of RAM and
> > certainly never write to it.
>
> Not a good idea. Implementing your suggestion would mean that large parts
> the page tables which are are just truncated off would have to be allocated
> and memory. Just mmaping 1gb from /dev/zero would cost you over 1mb of
> *not swappable* memory for page tables. Aside of that allocation and filling
> consumes a lot of time.

a very good idea since page tables are in virtual memory and swappable
themself in VMS...

Harald

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