Re: 2.1.111: IDE DMA disabled...BLAH...BLAH...

Alan Cox (
Wed, 29 Jul 1998 20:46:43 +0100 (BST)

> On Wed, 29 Jul 1998, Mark Lord wrote:
> >
> > Yet, for some inexplicable reason, Linux continues to default
> > to "external cache == ON" on all systems, when it would be a
> > heck of a lot better off to disable caches at boot time.
> >
> > After all, a user-level utility could easily be written (with
> > kernel hooks) to turn the caches on after booting, if safe to do so.
> Umm. The difference between "cache on" and "cache off" is a bit more
> drastic than "use DMA for IDE" and "don't use DMA for IDE", wouldn't you
> say?
> You can test it if you wish.

For reference with caches off and UDMA on my machine builds kernels faster
than with caches on and UDMA off.


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