On 10/09/18 10:41 AM, Christoph Hellwig wrote: > 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 just saw you added that "helper" in your tree. Please don't, it is > a negative value add as it doesn't help anything with the checking. Alright, so what's the consensus then? Just have a check in nvmet_bdev_execute_rw() to add REQ_NOMERGE when appropriate? Jens is pretty dead set against adding to the common path. Logan P.S. Here's the commit in question for anyone else on the list: https://github.com/sbates130272/linux-p2pmem/commit/eeabe0bc94491d3eec4fe872274a9e3b4cdea538