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Re: "route_enqueue: queue full, dropped message" blast from a 8.99.32 amd64 domU



At Fri, 10 May 2019 13:05:04 +0100, Roy Marples <roy%marples.name@localhost> wrote:
Subject: Re: "route_enqueue: queue full, dropped message" blast from a 8.99.32 amd64 domU
>
> I would imagine that if an interface is interupting that much then
> it's constantly sending messages to route(4) to say that it's up/down
> and addresses are detached/tentative in a tight loop. The queueing
> mechanism has a fixed length and while we go out of our way to notify
> userland if there's an error sending these messages, we can't send
> this one at all so we just log it.
>
> So it's an artifact of your interupt storm, but not the cause.

Thanks Roy!

I'm afraid I was too distracted with other things at the time to look to
see if I could identify which device might have accounted for the extra
interrupts.

I kind of assumed they were all from the console driver, though I just
did a test and now realize that even at full speed it can't account for
nearly the magnitude of interrupts per second that I was seeing.

During normal operation I see just over 8000/s (and with the console
spewing there are only about 200/s more), and it all seems to add up
since this is an 8-vcpu domU, and I have HZ=1000.  Before I rebooted I
was seeing numbers ranging up to 25000/s.

So, what in the world could make either the single xennet0 interface, or
the lo0 interface for that matter, bounce in such a fashion I wonder.

As far as I can tell from old console log files this did not happen in
the first few years of life of this system (from about 2015) when it
(and its dom0) was running 7.99.various.

--
					Greg A. Woods <gwoods%acm.org@localhost>

+1 250 762-7675                           RoboHack <woods%robohack.ca@localhost>
Planix, Inc. <woods%planix.com@localhost>     Avoncote Farms <woods%avoncote.ca@localhost>

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