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

On 9/5/18 1:56 PM, Christoph Hellwig wrote:

On Wed, Sep 05, 2018 at 01:45:04PM -0600, Jens Axboe wrote:

quoted

The point is that the caller doesn't necessarily know where the bio
will end up, hence the caller can't fully check if the whole stack
supports P2P.

The caller must necessarily know where the bio will end up, as for P2P
support we need to query if the bio target is P2P capable vs the
source of the P2P memory.

Then what's the point of having the check at all?

-- 
Jens Axboe