Vincent BARAT wrote:
> Hello,
> 
> I upgraded my Centris 650 from 16 Mo to 32 Mo last night, and of course
> saw a very big improvement of NetBSD performances under X11 and XEmacs 20.3...
> 
> I tried to overload my mac, just to see how it handles that load, by starting
> several XEmacs and Mosaic one after another, and using xosview to monitor my system state.

Please, have your email client wrap lines at around 76 columns. :-)

> What I don't understand is the following:
> 
> After 1 AfterStep, 2 XEmacs and 2 Mosaic, my real memory was full
> , but swap was not used at all. With 2 more Mosaic and 2 more XEmacs,
> my virtual memory, i.e. my swap (25 Mo according to xosview, and I believe it because
> it is the size of my swap partition :-)) was full.

Hmmmm...you might want to use systat or vmstat instead.  Perhaps they are
more reliable, although Brian Grayson would probably know more.
 
> At this point, I thought that I would not be able to start another application, but
> I was able to start at least 2 more XEmacs and 1 more Mosaic. So my question is:
> Where does NetBSD take this new memory ?

Good question.  My guess would be xosview isn't accurately reporting how
much swap you're using.  The other guess would be that shared libraries
really work :-)  If all you're doing is opening up multiple copies of the
same program, they should be able to share most of code and data until you
do something different with them.

> Also, another question:
> 
> If I manage to really overload virtual memory, what would be the behavior of NetBSD ?

I'm not sure, but on my 8MB SE/30, the machine hung solid when I tried to
start X and I had _no_ swap configured.  I would suspect a similar
reaction if you actually ran out.

Later.

-- 
Colin Wood                                 cwood@ichips.intel.com
Component Design Engineer - MD6                 Intel Corporation
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I speak only on my own behalf, not for my employer.