Re: [dpdk-dev] [PATCH] eventdev: Add rte_errno return values to the enqueue and dequeue functions

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

On Mon, Feb 13, 2017 at 10:38:55AM +0000, Bruce Richardson wrote:
> On Fri, Feb 10, 2017 at 03:02:21PM -0600, Gage Eads wrote:
> > This change allows user software to differentiate between an invalid argument
> > (such as an invalid queue_id or sched_type in an enqueued event) and
> > backpressure from the event device.
> > 
> > The port and device ID checks are placed in RTE_LIBRTE_EVENTDEV_DEBUG header
> > guards to avoid the performance hit in non-debug execution.
> > 
> > Signed-off-by: Gage Eads <gage.eads@intel.com>
> > ---
> 
> Do we have some idea of the performance hit from these? It may be too
> soon to know, given we don't have many drivers to test with, but if
> there is no perf hit seen with the SW driver, I think we should look to
> just always do this, rather than having it compile-time off. If it does

IMO, It is better put to under compile-time like ethdev. It is
difficult predict the performance regression on wide range of cores that DPDK
runs now. I think we need to add following additional checks based on
Gage header file change

1) Per event queue ID is valid or not?
2) Per event's sched type doesn't match the capabilities of the destination queue.


> prove to be a performance problem we can look to #ifdef it out later.
> 
> /Bruce