Re: 2.4.x VM problems thread

[Luigi Genoni]

On Tue, 7 Aug 2001, Mike Fedyk wrote:

> On Wed, Aug 08, 2001 at 02:24:37AM +0200, Luigi Genoni wrote:
> > This kind of code would kill any Unix system, i think, not just linux 2.4
> > boxes.
> >
>
> I tried it on 2.2.19-ppc and could kill it with ^C at the prompt, or from
> root if I was already logged in.  Trying to iniate connections to ssh didn't
> produce any results after about 30 seconds.
with linux 2.2 if you run this program and then try to run another process
you will get a "cannot fork" message.
no cresh if you can make a ^C or a killall, (you should not be able to run
a ps). This is the same behaviour of Solaris. With Linux 2.4 you will
start to fill your swap. kswapd will really stress your system. then you
should not be able to run any process. If X11 is running, it will be
freezed.  Same thing if you run AIX and Irix. Note that AIX and Irix are
quite different on any point of view if you go to process management :).

mmm, HP-UX 10.20 should get frozen too, while HP-UX 11 should act like
Linux 2.2 (not sure about this, I should check). I do not know about
FreeBSD.

What changes is the way the system acts when it has to execute a code like
for (;;)
	fork();

That is not related to vm. It is just how fork() is managed.

Note also that libc matters.

>
> Once it was killed the system was fine.
>
> Haven't tried 2.4 yet...
>

you will see a different behaviour.

bests
Luigi