Re: [RFC PATCH 00/28] Removing struct page from P2PDMA

Jason Gunthorpe
2019-06-24T18:16:32Z

On Mon, Jun 24, 2019 at 10:53:38AM -0600, Logan Gunthorpe wrote:
> > It is only a very narrow case where you can take shortcuts with
> > dma_addr_t, and I don't think shortcuts like are are appropriate for
> > the mainline kernel..
>
> I don't think it's that narrow and it opens up a lot of avenues for
> system design that people are wanting to go. If your high speed data
> path can avoid the root complex and CPU, you can design a system which a
> much smaller CPU and fewer lanes directed at the CPU.

I mean the shortcut that something generates dma_addr_t for Device A
and then passes it to Device B - that is too hacky for mainline.

Sounded like this series does generate the dma_addr for the correct
device..

Jason