Re: [PATCH 5/6] vhost: add a flag to enable Tx zero copy

2016-09-08 15:21, Yuanhan Liu:

On Wed, Sep 07, 2016 at 06:00:36PM +0200, Thomas Monjalon wrote:

quoted

2016-09-06 17:55, Yuanhan Liu:

quoted

On Tue, Sep 06, 2016 at 09:00:14AM +0000, Xu, Qian Q wrote:

quoted

Just curious about the naming: vhost USER TX Zero copy. In fact, it's Vhost RX zero-copy
For virtio, it's Virtio TX zero-copy. So, I wonder why we call it as Vhost TX ZERO-COPY, 
Any comments? 

It's just that "Tx zero copy" looks more nature to me (yes, I took the
name from the virtio point of view).

Besides that, naming it to "vhost Rx zero copy" would be a little
weird, based on we have functions like "virtio_dev_rx" in the enqueue
path while here we just touch dequeue path.

OTOH, I seldome say "vhost-user Tx zero copy"; I normally mention it
as "Tx zero copy", without mentioning "vhost-user". For the flag
RTE_VHOST_USER_TX_ZERO_COPY, all vhost-user flags start with "RTE_VHOST_USER_"
prefix.

I agree that the naming in vhost code is quite confusing.
It would be better to define a terminology and stop mixing virtio/vhost
directions as well as Rx/Tx and enqueue/dequeue.

I think we could/should avoid using Rx/Tx in vhost, but we should keep
the enqueue/dequeue: that's how the two key vhost API named.

quoted

Or at least, it should be documented.

Or, how about renaming it to RTE_VHOST_USER_DEQUEUE_ZERO_COPY, to align
with the function name rte_vhost_dequeue_burst?

Seems reasonable, yes.