RELENG_7: interrupt eating whole cpu core

[Tom Evans]

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.

> >> # 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
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