RELENG_7: interrupt eating whole cpu core

[Pieter de Goeje]

On Friday 08 February 2008, Tom Evans wrote:
> On Fri, 2008-02-08 at 17:14 +0100, Dominic Fandrey wrote:
> > Tom Evans wrote:
> > > If I try to turn on DMA, I just get WDMA2, which just doesn't cut it:
> >
> > I think any DMA mode is fast enough to handle a DVD drive. There's just
> > no necessity for more.
>
> WDMA is not UDMA. Any UDMA variant would be enough. WDMA2 provides a
> maximum of 16MiB/s, which will frequently lead to buffer underruns
> viewing a DVD. UDMA2 provides a maximum of 33MiB/s, which IS plenty.
DVD video is encoded at max. ~7Mbit/sec, which is way below 16MB/sec. You 
should have no problems viewing dvds.

>
> > >> # atacontrol mode acd0 udma5
> > >
> > > current mode = WDMA2
> >
> > Same as for me. I'm satisfied with the speed of the drive.
>
> I'm rarely satisfied - I'm quite often not bothered enough to pursue :)
>
> Tom

-- 
Pieter de Goeje