Re: Enabling peer to peer device transactions for PCIe devices

From: Dan Williams
Date: Tue Dec 06 2016 - 17:02:28 EST


On Tue, Dec 6, 2016 at 1:47 PM, Logan Gunthorpe <logang@xxxxxxxxxxxx> wrote:
> Hey,
>
>> Okay, so clearly this needs a kernel side NVMe specific allocator
>> and locking so users don't step on each other..
>
> Yup, ideally. That's why device dax isn't ideal for this application: it
> doesn't provide any way to prevent users from stepping on each other.

On this particular point I'm in the process of posting patches that
allow device-dax sub-division, so you could carve up a bar into
multiple devices of various sizes.