Re: Real-Time Preemption, -RT-2.6.12-final-V0.7.51-17

[William Weston <weston@sysex.net>]

On Fri, 8 Jul 2005, Ingo Molnar wrote:

> > > ok, you are right, the edge case was mishandled - but i think it was 
> > > already mishandled upstream, we just never (or rarely) triggered it.  
> > > I've reworked this area based on your patch, could you check -51-15, 
> > > does it work for you?

I figured it would take a little reworking, especially with your recent
MSI changes.  This was just a 'works for me' patch.  Your end_irq() is
cleaner, IMHO.

> > if it doesnt work, could you disable CONFIG_X86_IOAPIC_FAST?
> 
> or rather, please try -51-16. One of my testsystems produced weird 
> interrupt storms, which were caused by the IOAPIC_POSTFLUSH 
> optimization. In -51-16 i've turned that optimization off, globally.  
> Maybe this explains some of the other lockups reported.

OK.  Running -51-17 on the Athlon box.  CONFIG_X86_IOAPIC_FAST is still
enabled.  No lockups.  No jack xruns.  Max wakeup-latency is 27us (so far)  
on the debug config.  Nothing out of the ordinary logged except for the
new stack-footprint maximums during boot.

Any need to go back and check -51-16 as well?  Or -51-17 on a non-debug 
config?

--ww