Re: [PATCH v2 0/2] add tracepoints for nvme command submission and completion

[Keith Busch]

On Tue, Jan 16, 2018 at 03:28:19PM +0100, Johannes Thumshirn wrote:
> Add tracepoints for nvme command submission and completion. The tracepoints
> are modeled after SCSI's trace_scsi_dispatch_cmd_start() and
> trace_scsi_dispatch_cmd_done() tracepoints and fulfil a similar purpose,
> namely a fast way to check which command is going to be queued into the HW or
> Fabric driver and which command is completed again.

I like this very much, thanks for doing this. I think you could make the
submission trace point tighter for PCI as Hannes was suggesting since
an MMIO write can't fail, but doesn't look as doable for FC and RDMA.