Subject: Re: measuring interrupt latency etc.
To: None <thorpej@zembu.com, eeh@turbolinux.com>
From: Wolfgang Solfrank <ws@tools.de>
List: tech-kern
Date: 05/03/2000 19:09:37
Hi,

> > Actually, I'm pretty sure mi_switch() is supposed to be called at
> > splstatclock().
> 
> Yes, I know.  But it never lowers the IPL so if an interrupt is taken
> there it's not because it had interrupts disabled too long and then
> dropped the IPL.  Unless there's something strange on the '060 and IPL
> transitions don't take effect immediately but are delayed for some number
> of instructions.

Hmm, just guessing here, but are you sure that the stack backtrace is
correct via the interrupt?  On some (most?) architectures getting the
backtrace right for those is not easy (to say the least).  Just a thought...

You might want to ananlyze the stack frames by hand.

Ciao,
Wolfgang
-- 
ws@TooLs.DE     Wolfgang Solfrank, TooLs GmbH 	+49-228-985800