[MUD-Dev] Re: Is worse better?

[Vadim Tkachenko]

Ben Greear wrote:

[skipped]

> Btw, religion aside:  How can any one process die and crash a
> (multi-tasking) kernel?  Ie, como se dice 'Blue Screen'???  I mean, as
> root I can take down my Linux box, but I've never been able to crash the
> kernel, or even openwindows.

Well, it's possible to render the Linux box unusable. Can't give you the
reproductible sequence because the authors apparently fixed the problem
in next release, but here's a brief description:

- Tool: TogetherJ by www.oi.com - object modelling tool, 100% Java;
- Method: start it, and then try to select the menu item at the wrong
time;
- Result: somehow the app manages to grasp all the input and it's not
possible to use the keyboard anymore (and display is not being
refreshed). A few seconds later mouse stops responding. Several dozens
of seconds later the load goes so high that the networking connections
aren't accepted anymore adn it's impossible to telnet in and kill the
offender.

Strictly speaking, this is not a crash, but a denial of service attack,
but the result was the same.

Linux 2.0.30, Java port 1.1.3.

I was so pissed.

In general, 2.0.+ kernels seem to be pretty stable - I didn't have any
problems with either single processor and SMP computers with any kinds
of bizarre hardware. 1.2.13 used to crash a lot.

> Ben

--
Still alive and smile stays on,
Vadim Tkachenko <vt at freehold.crocodile.org>
--
UNIX _is_ user friendly, he's just very picky about who his friends are