Re: [PATCH v5 07/13] block: Add PCI P2P flag for request queue and check support for requests

[Christoph Hellwig]

On Wed, Sep 05, 2018 at 03:03:18PM -0600, Logan Gunthorpe wrote:
> There is no special p2p submission process. In the nvme-of case we are
> using the existing process and with the code in blk-core it didn't
> change it's process at all. Creating a helper will create one and I can
> look at making a pci_p2pdma_submit_bio() for v6; but if the developer
> screws up and still calls the regular submit_bio() things will only be
> very subtly broken and that won't be obvious.

I thought about that when reviewing the previous series, and even
started hacking it up.  In the end I decided against it for the above
reason - it just adds code, but doesn't actually help with anything
as it is trivial to forget, and not using it will in fact just work.