Martin 53N 1W wrote:

Michael D. Ober wrote:

[...]

Actually, since Windows shares read-only executable images in
memory and

[...]

however.  Windows does other performance tricks such as not writing
 read-only pages to the swap file.  Instead, it simply discards
them and then re-reads them back from the original location on
disk, thus saving a disk write when the EXE's physical memory is
needed for other processes or data. I assume that all modern OS's,
including Linux, do this as well.

[...]

doubt that such a 'bolt-on' optimisation would be accepted. The linux

[...]

I got that last bit wrong (:-((

The true case is summarised in this email just now:

###
Linux and modern Unices page off the pure code parts of the actual
executable files - they do not copy unmodified pages into the swap
file.  Windows copied Unix.
###


From discussions just now, linux already does the two above mentioned
memory useage optimisations.

(There's lots more besides...)


Regards,
Martin