[dpdk-dev] [PATCH v2] event/sw: perform partial burst enqueues

[Van Haaren, Harry]

> From: Eads, Gage
> Sent: Monday, March 12, 2018 2:55 PM
> To: dev at dpdk.org
> Cc: jerin.jacob at caviumnetworks.com; Van Haaren, Harry
> <harry.van.haaren at intel.com>
> Subject: [PATCH v2] event/sw: perform partial burst enqueues
> 
> Previously, the sw PMD would enqueue either all or no events, depending on
> if enough inflight credits were available for the new events in the burst.
> If a port is enqueueing a large burst (i.e. a multiple of the credit update
> quanta), this can result in suboptimal performance, and requires an
> understanding of the sw PMD implementation (in particular, its credit
> scheme) to tune an application's burst size.
> 
> This affects software that enqueues large bursts of new events, such as the
> ethernet event adapter which uses a 128-deep event buffer, when the input
> packet rate is sufficiently high.
> 
> This change makes the sw PMD enqueue as many events as it has credits, if
> there are any new events in the burst.
> 
> Signed-off-by: Gage Eads <gage.eads at intel.com>


Agree that making forward progress by enqueuing what we have credits for
makes sense for the application.

No performance degradation here, thanks for the patch:

Acked-by: Harry van Haaren <harry.van.haaren at intel.com>