Re: Xterm Hangs - Possible scheduler defect?

From: Paulo Marques
Date: Fri Feb 25 2005 - 10:56:45 EST


Ingo Oeser wrote:
Chris Friesen wrote:

Ingo Oeser wrote:
[...]
You would need to change the priority of task 1 until it releases the
mutex. Ideally the owner gets the maximum priority of
his and all the waiters on it, until it releases his mutex, where he regains
its old priority after release of mutex. But this priority elevation happens
only, if he is runnable. If not, he gets his old priority back, until he is runnable.

This is called a "priority inversion" problem, and there was some work done by Ingo Molnar to make the scheduler aware of such cases and handle them appropriatelly.

You can follow this thread for more info:

http://marc.theaimsgroup.com/?l=linux-kernel&m=110106915415886&w=2

I really don't know what's the current state, but this is nothing new...

--
Paulo Marques - www.grupopie.com

All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke (1729 - 1797)
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