Re: Dirty patch saving 260K on Triton

Pavel Machek (pavel@Elf.mj.gts.cz)
Sat, 10 May 1997 15:55:56 +0200


> Hi,
>
> > There are programs for DOS (TLBMM, umb_driver) that can enable additional
> > memory for many chipsets. On some chipsets that memory (or part of it) is
> > DMAble, on some not. Some time ago I wrote a patch that made use of that
> > enabled memory. But on some chipsets I have seen problems when memory was
> > told to be DMAble and I allowed to use it by DMA under linux. Maybe it
> > wasn't REALLY dmable?
>
> DMAbility of this memory is usually settable in configuration registers
> of the PCI<->ISA bridge... It will require some testing.
>
> On chipsets where it's impossible, we can simply flag these pages as
> non-DMAble.

What about setting all memory non-DMAable between 640k and 1M?

DMA will not work in small area, but that area is probably too small to
care.

-- 
--
I'm really pavel@atrey.karlin.mff.cuni.cz. 	   Pavel
Look at http://atrey.karlin.mff.cuni.cz/~pavel ;-).