Re: ide-cs using 100% CPU

Hamie
2004-08-06T19:39:57Z

Russell King wrote:

>On Sun, Jul 18, 2004 at 10:30:16AM +0100, Hamie wrote:
>
>
>>Anyone know why this happens? Something busy waiting? (BUt that should
>>show as system cpu right?) or something taking out really long locks?
>>
>>
>
>It'll be because IDE is using PIO to access the CF card, which could
>have long access times (so reading a block of sectors could take some
>time _and_ use CPU.) Obviously, PIO requires the use of the CPU, so
>the CPU can't be handed off to some other task while this is occuring.
>
>
>
Well... I did consider that. And not to disbelieve you, since you know
the kernel way better than I do, But decided I was being silly that a
1.6GHz Pentium-M processor should use 100% CPU moving a couple of
MB/second across a CF interface...

Is 100% CPU not excessive? IIRC my PIII-750 used to use less CPU doing
the same job as quick, or even slightly faster...

And should it not use system CPU rather than user CPU?

TIA
Hamish.