Re: [announce] [patch] limiting IRQ load, irq-rewrite-2.4.11-B5

jamal
2001-10-04T18:35:48Z

On Thu, 4 Oct 2001, Andreas Dilger wrote:

> On Oct 04, 2001 07:34 -0400, jamal wrote:
> > 1) you shut down shared interupts; take a look at this posting by Marcus
> > Sundberg <marcus@cendio.se>
> >
> > ---------------
> >
> > 0: 7602983 XT-PIC timer
> > 1: 10575 XT-PIC keyboard
> > 2: 0 XT-PIC cascade
> > 8: 1 XT-PIC rtc
> > 11: 1626004 XT-PIC Toshiba America Info Systems ToPIC95 PCI
> > \
> > to Cardbus Bridge with ZV Support, Toshiba America Info Systems ToPIC95
> > PCI \
> > to Cardbus Bridge with ZV Support (#2), usb-uhci, eth0, BreezeCom Card, \
> > Intel 440MX, irda0 12: 1342 XT-PIC PS/2 Mouse
> > 14: 23605 XT-PIC ide0
> >
> > -----------------------------
> >
> > Now you go and shut down IRQ 11 and punish all devices there. If you can
> > avoid that, it is acceptable as a temporary replacement to be upgraded to
> > a better scheme.
>
> Well, if we fall back to polling devices if the IRQ is disabled, then the
> shared interrupt case can be handled as well. However, there were complaints
> about the patch when Ingo had device polling included, as opposed to just
> IRQ mitigation.
>

I dont think youve followed the discussions too well and normally i
wouldnt respond but you addressed me. Ingos netdevice polling is not the
right approach, please look at NAPI and read the paper. NAPI does
all what youve been suggesting. We are not even discussing that at this
point. We are discussing the sledgehammer effect and how you could break a
finger or two trying to kill that fly with it. The example above
illustrates it.

cheers,
jamal