[LAD] rtirq script is broken with 2.6.31

[Paul Davis]

On Fri, Aug 7, 2009 at 9:32 AM, Rui Nuno Capela<rncbc at rncbc.org> wrote:

> this time however it looks that you can actually improve things when
> several device drivers are hanging on a irq line. that is, one can tune
> up the one and only the one actually intended (eg. "snd" => "irq/17-HDA
> Inte" and nothing else)

not so fast. unless things have *really* changed in h/w (and they may
have) when the CPU sees a IRQ 17, it will still have to execute at
least every handler until one of them says "yes it was me", and
depending on the kernel design right now, possibly all of them. ergo,
its not clear you will benefit from raising the priority of one versus
the others. i'd be interested in hearing/reading the arguments for
per-driver threads for this - on the face of it it seems rather odd to
me.