[FUG-BR] Problemas com hardware

[Luiz Otávio Souza]

From: "Marcelo V. Lima" <snap em catho.com>

> mas nao eh o PAE que habilita high memory?

O PAE habilita o acesso a mais de 32bits de memoria (4GB RAM) e tem varios 
problemas e limites na sua implementação.

Esse assunto surgiu na lista do DFBSD recentemente, veja abaixo:


> On Wed, Jun 08, 2005 at 10:18:02AM -0700, Matthew Dillon wrote:
> >     We don't have any PAE code in DragonFly.  I don't currently intend
> >     to add it... it's a severe hack.i [snip]
>
>
> Let me elaborate a bit more on this. PAE makes the kernel work a lot
> harder, because the kernel can't access all memory at the same time.
> This means that you have to be a lot more careful when accessing
> memory, since it might currently not be present.
>
> It also adds the general problem of 64bit machines in that many PCI
> bus master devices still only support "low" memory (below 4GB). For
> this reason you often don't gain anything from using it e.g. for
> buffer caching, since you have to copy it into the low memory or
> reverse before doing IO.
>
> Joerg


Luiz - loos
PS: essa mensagem do dfbsd precisa de duas traduções, uma para o portugues e 
outra para linguagem de usuario... isso que é falar dificil... 


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