Re: Interrupt storm mitigation needed

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Tue, Feb 17, 2015 at 01:47:50PM +0100, Tom Ivar Helbekkmo wrote:
> Joerg Sonnenberger <joerg%britannica.bec.de@localhost> writes:
> 
> > If it still generates interrupts, there is not much we can do. I do not
> > believe turning off interrupts on the PIC is in any way appropiate.
> 
> All right, but before we drop this, could you help me understand your
> experimental patch that I'm running?  It looks to me as if you're never
> enabling the uhci interrupts, instead scheduling the first of a series
> of callouts, with the intention that each such callout will end up
> re-scheduling a new one.

Correct.

> (There is a code path in uhci_intr1() that
> would break this chain.

Possible, not intentional. So if I missed a branched, fell free to add
the callout_schedule in it :)

> If I do, I'm also thinking that the same idea could easily be applied to
> ehci, right?  That's now my largest source of unwanted interrupts at the
> physical level, so I figure it's worth it to do the same thing there.

Yeah, if it has the same problem.

Joerg