On Feb  9 09:12, Keith Busch wrote:
> From: Keith Busch <kbusch@kernel.org>
> 
> Add support for NVMe TP4146 Flexible Data Placemen, allowing placement
> identifiers in write commands. The user can enabled this with the new
> "fdp=1" parameter for fio's io_uring_cmd ioengine. By default, the fio
> jobs will cycle through all the namespace's available placement
> identifiers for write commands.

Technically, the namespace has Placement *Handles* associated and when
writing, a Placement *Identifier* is used to also specify the Reclaim
Group.

> The user can limit which placement
> identifiers can be used with additional parameter, "fdp_plis=<list,>",
> which can be used to separate write intensive jobs from less intensive
> ones.

With the above in mind, it might make sense to align with the spec and
call this "fdp_pids" instead. As far as I can tell, fio won't cycle
through reclaim groups and create the pid on its own, without fdp_plis
explicitly indicating it?