Re: [RFC][PATCH] Expanding the size of "start" and "end" field in "struct resource"

From: Benjamin LaHaise
Date: Wed Mar 15 2006 - 17:10:26 EST


On Wed, Mar 15, 2006 at 02:59:54PM -0700, Eric W. Biederman wrote:
> Actually now that I think back there are machines with < 4GiB of ram
> with 64bit pci BAR values. It is more common to have 32bit values BAR
> values and > 4GiB of ram.

Such machines on x86 would have to be compiled with PAE. Ditto any other
architecture, as you *have* to be able to represent those physical addresses,
which requires having page tables that can map them, which requires whatever
PAE is on the platform.

> Nor do I think struct resource is nearly as important when being
> efficient, as dma_addr_t. struct resource is only used during
> driver setup which is a very rare event. A few extra instructions
> there likely will get lost in the noise and most of the will probably
> be removed because they are in an __init section anyway.

Bloat for no good reason is a bad habit to get into.

-ben
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