Re: Real-Time Preemption, -RT-2.6.12-final-V0.7.50-24

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 2005-07-12 at 16:02 +0200, Ingo Molnar wrote:
> * Karsten Wiese <[email protected]> wrote:
> 
> > Hi Ingo
> > 
> > I've refined io_apic.c a little more:
> 
> great. I've applied these changes and have released the -28 patch. (note 
> that the last chunk of your patch was malformed, have applied it by 
> hand.)
> 
> i'm wondering what your thoughts are about IOAPIC_POSTFLUSH - i had to 
> turn it on unconditionally again, to get rid of spurious interrupts and 
> outright interrupt storms (and resulting lockups) on some systems.  
> IOAPIC_POSTFLUSH is now causing much of the IO-APIC related IRQ handling 
> overhead.

I observed a situation on a dual xeon where IOAPIC_POSTFLUSH , if on,
would actually cause spurious interrupts. It was odd cause it's suppose
to stop them .. If there was a lot of interrupt traffic on one IRQ , it
would cause interrupt traffic on another IRQ. This would result in
"nobody cared" messages , and the storming IRQ line would get shutdown.

This would only happen in PREEMPT_RT .

Daniel

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]
  Powered by Linux