Re: [dpdk-dev] [PATCH] ethdev: additional parameter in RX callback

[Neil Horman <nhorman@tuxdriver.com>]

On Thu, Mar 12, 2015 at 04:54:27PM +0000, John McNamara wrote:
> 
> This patch is a minor extension to the recent patchset for RX/TX callbacks
> based on feedback from users implementing solutions based on it.
> 
> The patch adds a new parameter to the RX callback to pass in the number of
> available RX packets in addition to the number of dequeued packets.
> This provides the RX callback functions with additional information
> that can be used to decide how packets from a burst are handled.
> 
> The TX callback doesn't require this additional parameter so the RX
> and TX callbacks no longer have the same function parameters. As such
> the single RX/TX callback has been refactored into two separate callbacks.
> 
> Since this is an API change we hope it can be included in 2.0.0 to avoid
> changing the API in a subsequent release.    
> 
> 
> John McNamara (1):
>   ethdev: added additional packet count parameter to RX callbacks
> 
>  examples/rxtx_callbacks/main.c |    3 +-
>  lib/librte_ether/rte_ethdev.c  |    8 ++--
>  lib/librte_ether/rte_ethdev.h  |   74 ++++++++++++++++++++++++++--------------
>  3 files changed, 54 insertions(+), 31 deletions(-)
> 
> -- 
> 1.7.4.1
> 
> 


Well, we're well past the new feature phase of this cycle, so I would say NACK.
I would also suggest that you don't need to modify ABI to accomodate this
feature.  Instead just document the pkts array to be terminated by a reserved
value, so that the callback can determine its size dynamically.  You could
alternatively create a new api call that allows you to retrieve that information
from the context of the callback.

Neil