Re: [Kiobuf-io-devel] RFC: Kernel mechanism: Compound event wait

[Alan Cox]

> In fact, regular IDE DMA allows arbitrary scatter-gather at least in
> theory. Linux has never used it, so I don't know how well it works in

Purely in theory, as Jeff found out. 

> But despite a lot of likely practical reasons why it won't work for
> arbitrary sg lists on plain IDE DMA, there is no _theoretical_ reason it
> wouldn't. And there are bound to be better controllers that could handle
> it.

I2O controllers are required too handle it (most dont) and some of the high
end scsi/fc controllers even get it right