Re: [patch] 2.4.1, 2.4.2-pre3: APIC lockups

[Manfred Spraul <manfred@colorfullife.com>]

"Maciej W. Rozycki" wrote:
> 
> Hi,
> 
>  After performing various tests I came to the following workaround for
> APIC lockups which people observe under IRQ load, mostly for networking
> stuff.  I believe the test should work in all cases as it basically
> implements a manual replacement for EOI messages.  In my simulated
> environment I was unable to get a lockup with the code in place, even
> though I was getting about every other level-triggered IRQ misdelivered.
> 
>  Please test it extensively, as much as you can, before I submit it for
> inclusion.  If you ever get "Aieee!!!  Remote IRR still set after unlock!"
> message, please report it to me immediately -- it means the code failed.
>
No messages.

> There is also an additional debugging/statistics counter provided in
> /proc/cpuinfo that counts interrupts which got delivered with its trigger
> mode mismatched.  Check it out to find if you get any misdelivered
> interrupts at all.
> 
I'm running my default webserver load test, and I get ~40 /second, 92735
total.

bw_tcp says 1.13 MB/sec, that's wire speed.

tcpdump | grep 'sack ' doesn't show unusually many lost packets.

Look promising.

--
	Manfred