copy-on-write

Hi

Looking at
http://squid.nlanr.net/Squid/Devel/todo.html
http://squid.nlanr.net/Squid/Devel/Todo/9703122.txt

I don't think that this is necessary (at least with linux, probably with
newer versions of solaris too, from what I have heard)

Most use a "Copy-On-Write" method when they fork. This means that they
share pages, unless either of the processes write to a page, in which
case the OS then duplicates the page.

This means that if a 400M program forks and then execs another process,
you don't need 800M of ram to do it, and all it does is insert a process
into the process list (thus adding a little struct to a table).

So - is there something I am missing?

This may also be called "demand-zero" paging?

        Oskar

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'experience made art, but inexperience luck.'
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Received on Tue Jul 29 2003 - 13:15:41 MDT