Hi Maxime, > -----Original Message----- > From: Maxime Coquelin <mcoqu...@redhat.com> > Sent: Tuesday, June 8, 2021 12:17 AM > To: Wang, YuanX <yuanx.w...@intel.com>; dev@dpdk.org > Cc: maxime.coque...@redhat.com; Xia, Chenbo <chenbo....@intel.com>; > Jiang, Cheng1 <cheng1.ji...@intel.com>; Ma, WenwuX > <wenwux...@intel.com>; Hu, Jiayu <jiayu...@intel.com> > Subject: Re: [PATCH 1/1] lib/vhost: support async dequeue for split ring > > Hi Yuan, > > This is a first review, I will certainly have more comments later. > > On 6/2/21 10:31 AM, Yuan Wang wrote: > > This patch implements asynchronous dequeue data path for split ring. > > A new asynchronous dequeue function is introduced. With this function, > > the application can try to receive packets from the guest with > > offloading large copies to the DMA engine, thus saving precious CPU > > cycles. > > Do you have any number to share?
We cannot share the exact numbers without legal approval. There are some relative values: in PV cases, testpmd macfwd throughput of one core with async dequeue enabled is around 1.25x of SW vhost; when enabling both async enqueue and dequeue, one core macfwd throughput is up to 2x of SW vhost. > > > Signed-off-by: Wenwu Ma <wenwux...@intel.com> > > Signed-off-by: Yuan Wang <yuanx.w...@intel.com> > > Signed-off-by: Jiayu Hu <jiayu...@intel.com> > > --- > > doc/guides/prog_guide/vhost_lib.rst | 10 + > > examples/vhost/ioat.c | 30 +- > > examples/vhost/ioat.h | 3 + > > examples/vhost/main.c | 60 +-- > > lib/vhost/rte_vhost_async.h | 44 ++- > > lib/vhost/version.map | 3 + > > lib/vhost/virtio_net.c | 549 ++++++++++++++++++++++++++++ > > 7 files changed, 664 insertions(+), 35 deletions(-) > > Please split the patch in multple parts. > At least don't mix example and lib changes in the same patch. > > > diff --git a/doc/guides/prog_guide/vhost_lib.rst > b/doc/guides/prog_guide/vhost_lib.rst > > index 6b7206bc1d..785ab0fb34 100644 > > --- a/doc/guides/prog_guide/vhost_lib.rst > > +++ b/doc/guides/prog_guide/vhost_lib.rst > > @@ -281,6 +281,16 @@ The following is an overview of some key Vhost > API functions: > > Poll enqueue completion status from async data path. Completed packets > > are returned to applications through ``pkts``. > > > > +* ``rte_vhost_try_dequeue_burst(vid, queue_id, mbuf_pool, pkts, count, > nr_inflight)`` > > The function should contain async in its name. > > BTW, I think we should also rename below APIs while they are > experimental to highlight it is async related: > > rte_vhost_submit_enqueue_burst > rte_vhost_poll_enqueue_completed Yes, it's better to add "async" in related functions. How about: rte_vhost_async_submit_enqueue_burst rte_vhost_async_poll_enqueue_completed rte_vhost_async_try_dequeue_burst Any suggestions? Thanks, Jiayu
