[MacRuby-devel] System crash - MacRuby priority

[Perry E. Metzger]

On Sun, 07 Nov 2010 10:48:07 -0500 Robert Rice <rice.audio at pobox.com>
wrote:
> Hi Laurent:
> 
> I'm not sure what the definition of a "kernel panic" is.

It means your kernel dies and invokes its panic() function, resulting
in the system rebooting.

You describe a situation that is not a kernel panic, it is not even
strictly speaking a crash.

> My system
> Finder becomes unresponsive. A/V streams stop displaying video but
> continue to play audio and my MacRuby app continues to run to
> completion.

This is not a system crash, especially since (presumably) the
machine returns to normal after your app exits. In a system crash,the
machine dies and needs to be rebooted -- you are not experiencing
that.

The exact nature of what is going wrong is difficult to assess
without knowing much about what your Ruby code is doing.

> I have a busy CPU running a DisplayLink USB monitor connection and
> I suspect the DisplayLink driver could be involved if it doesn't
> get enough CPU resources. I will test it again with a newer
> DisplayLink driver and with the USB monitor connection. But it
> seems that MacRuby runs at a high priority since I can't reproduce
> the problem when I run the CPU up to 100% with other applications.

Your other applications do not behave the same way that your Ruby app
does so there is no particular reason to assume this has anything
to do with scheduler priorities at all.

It seems much more likely that this is related to the specific
behavior of your ruby app and is independent of scheduling priority.
For example, you could be tying up other resources needed by the
finder or A/V subsystems, such as disk bandwidth or memory.

-- 
Perry E. Metzger		perry at piermont.com