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/
