Re: ide-cs using 100% CPU

From: Russell King
Date: Fri Aug 06 2004 - 14:35:45 EST


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.

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/
2.6 Serial core
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