Re: [dpdk-dev] [PATCH v2] vhost: avoid memory barriers when no descriptors dequeued

2018-10-24 Thread Maxime Coquelin
On 10/23/18 12:07 PM, Maxime Coquelin wrote: In both split and packed dequeue paths, flush_shadow_used_ring and vhost_ring_call variants gets called even if not packets have been dequeued, and so no descriptors updates happened. It has an impact on CPU pipeline, as memory barriers are used in

Re: [dpdk-dev] [PATCH v2] vhost: avoid memory barriers when no descriptors dequeued

2018-10-24 Thread Tiwei Bie
On Tue, Oct 23, 2018 at 12:07:10PM +0200, Maxime Coquelin wrote: > In both split and packed dequeue paths, flush_shadow_used_ring > and vhost_ring_call variants gets called even if not packets > have been dequeued, and so no descriptors updates happened. > > It has an impact on CPU pipeline, as me

[dpdk-dev] [PATCH v2] vhost: avoid memory barriers when no descriptors dequeued

2018-10-23 Thread Maxime Coquelin
In both split and packed dequeue paths, flush_shadow_used_ring and vhost_ring_call variants gets called even if not packets have been dequeued, and so no descriptors updates happened. It has an impact on CPU pipeline, as memory barriers are used in these functions. This patch don't call these fun