Re: [dpdk-users] Run-to-completion or Pipe-line for QAT PMD in DPDK

[Changchun Zhang <changchun.zhang@oracle.com>]

Thanks!
Changchun (Alex)


-----Original Message-----
From: Trahe, Fiona [mailto:fiona.trahe@intel.com] 
Sent: Friday, January 18, 2019 11:26 AM
To: Changchun Zhang <changchun.zhang@oracle.com>; Pathak, Pravin <pravin.pathak@intel.com>; users@dpdk.org
Cc: Trahe, Fiona <fiona.trahe@intel.com>
Subject: RE: [dpdk-users] Run-to-completion or Pipe-line for QAT PMD in DPDK

Hi Alex,
> [changchun] In the same thread, but how about to dequeuer at the 
> beginning of the thread each time, if data presents then processing 
> them, if no data just do other work, and equeue the packets at some time but does not wait.
> For example:
> While(1)
> {
> 	Nb_ops = dequeuer();
> 	If(nb_ops > )
>              {
>                  process_dequeued_data();
>                  continue;
>              }
> 
>               Other_work();
>               If(ipsec)
>                   Enqueuer();
> }
> Does it make sense?
[Fiona] It can, though on the first loop ro after a queit time youll proably get very few back on first and second dequeue as It'll be called immediately after the enqueue. Once it gets busy that could be ok though
[changchun] Thank you Fiona. One more question, as you said, enqueuer/dequeue should be called within the same thread. Why? Is it because the other thread(lcore 1) cannot dequeuer the processed data from other thread(lcore 2)? But as the cryptograph device lib doc says, "it is howerver possible to use a different logical core to dequeuer an operation on a queue pair from the logical core which it was enqueued on". Looking forward to more details.