[dpdk-dev] [PATCH] eventdev: add producer enqueue hint

Eads, Gage gage.eads at intel.com
Mon Jun 26 17:44:10 CEST 2017



> -----Original Message-----
> From: Jerin Jacob [mailto:jerin.jacob at caviumnetworks.com]
> Sent: Monday, June 12, 2017 6:46 AM
> To: dev at dpdk.org
> Cc: Richardson, Bruce <bruce.richardson at intel.com>; Van Haaren, Harry
> <harry.van.haaren at intel.com>; hemant.agrawal at nxp.com; Eads, Gage
> <gage.eads at intel.com>; nipun.gupta at nxp.com; Vangati, Narender
> <narender.vangati at intel.com>; Rao, Nikhil <nikhil.rao at intel.com>; Jerin Jacob
> <jerin.jacob at caviumnetworks.com>
> Subject: [dpdk-dev] [PATCH] eventdev: add producer enqueue hint
> 
> Some PMD like OCTEONTX can have optimized handling of events if the PMD
> knows it is a producer pattern in advance.
> For instance, OCTEONTX PMD can support burst mode if op ==
> RTE_EVENT_OP_NEW.
> 
> Since the event producer initialize(set all_op_new == 1) the event object before
> the main producer loop, This scheme does not call for any performance
> regression on other PMDs.
> 
> Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
> ---
> Another option is to add a flag in enqueue API or have parallel enqueue API.
> ---
>  drivers/event/octeontx/ssovf_worker.c | 12 ++++++++++--
>  lib/librte_eventdev/rte_eventdev.h    | 10 +++++++++-
>  2 files changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/event/octeontx/ssovf_worker.c
> b/drivers/event/octeontx/ssovf_worker.c
> index ad3fe684d..209c595cf 100644
> --- a/drivers/event/octeontx/ssovf_worker.c
> +++ b/drivers/event/octeontx/ssovf_worker.c
> @@ -196,8 +196,16 @@ ssows_enq(void *port, const struct rte_event *ev)
> uint16_t __hot  ssows_enq_burst(void *port, const struct rte_event ev[],
> uint16_t nb_events)  {
> -	RTE_SET_USED(nb_events);
> -	return ssows_enq(port, ev);
> +	uint16_t i;
> +	struct ssows *ws = port;
> +
> +	if (ev[0].all_op_new) {
> +		rte_smp_wmb();
> +		for (i = 0; i < nb_events; i++)
> +			ssows_new_event(ws, &ev[i]);
> +		return i;
> +	} else
> +		return ssows_enq(port, ev);
>  }
> 
>  void
> diff --git a/lib/librte_eventdev/rte_eventdev.h
> b/lib/librte_eventdev/rte_eventdev.h
> index a248fe90e..1c1a46593 100644
> --- a/lib/librte_eventdev/rte_eventdev.h
> +++ b/lib/librte_eventdev/rte_eventdev.h
> @@ -933,7 +933,15 @@ struct rte_event {
>  			 * and is undefined on dequeue.
>  			 * @see RTE_EVENT_OP_NEW, (RTE_EVENT_OP_*)
>  			 */
> -			uint8_t rsvd:4;
> +			uint8_t all_op_new:1;
> +			/**< Valid only with event enqueue operation - This hint
> +			 * indicates that the enqueue request has only the
> +			 * events with op == RTE_EVENT_OP_NEW.
> +			 * The event producer, typically use this pattern to
> +			 * inject the events to eventdev.
> +			 * @see RTE_EVENT_OP_NEW
> rte_event_enqueue_burst()
> +			 */
> +			uint8_t rsvd:3;
>  			/**< Reserved for future use */
>  			uint8_t sched_type:2;
>  			/**< Scheduler synchronization type
> (RTE_SCHED_TYPE_*)
> --
> 2.13.1

I slightly prefer the parallel enqueue API -- I can see folks making the mistake of setting all_op_new without setting the op to RTE_EVENT_OP_NEW, and later adding a "forward-only" enqueue API could be interesting for the sw PMD -- but this looks fine to me. Curious if others have any thoughts.


More information about the dev mailing list