> -----Original Message-----
> From: Pravin Shelar [mailto:pshe...@nicira.com]
> Sent: Thursday, April 9, 2015 9:10 PM
> To: Traynor, Kevin; Daniele Di Proietto
> Cc: dev@openvswitch.org
> Subject: Re: [ovs-dev] [PATCH] netdev-dpdk: Change eth rx burst size.
>
> On Wed, Apr 8, 2015 at 8:43 AM, Kevin Traynor <kevin.tray...@intel.com>
> wrote:
> > Change eth rx burst size from 192 to 32. This significantly
> > improves performance for packets that will be forwarded
> > through dpdkvhost ports, as the max dpdkvhost tx burst
> > size (32) will not be exceeded. There are negligible
> > effects in other scenarios.
> >
> > Signed-off-by: Kevin Traynor <kevin.tray...@intel.com>
>
> Daniele,
> You mentioned that you are going to fix the issue by handling
> different burst size of vhost devices. Do you have the fix?
It wasn't clear in the commit message but just to clarify, the
dpdkvhost max burst size is set in the DPDK vhost library and if
we try and enqueue >32 packets only 32 will be enqueued. We can
add a back-off/retry but it will give better performance to
ensure that the vhost burst size is not exceeded.
>
> > ---
> > lib/netdev-dpdk.c | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> > index f69154b..eb51072 100644
> > --- a/lib/netdev-dpdk.c
> > +++ b/lib/netdev-dpdk.c
> > @@ -145,7 +145,7 @@ static const struct rte_eth_txconf tx_conf = {
> > .txq_flags = ETH_TXQ_FLAGS_NOMULTSEGS|ETH_TXQ_FLAGS_NOOFFLOADS,
> > };
> >
> > -enum { MAX_RX_QUEUE_LEN = 192 };
> > +enum { MAX_RX_QUEUE_LEN = 32 };
> > enum { MAX_TX_QUEUE_LEN = 384 };
> > enum { DPDK_RING_SIZE = 256 };
> > BUILD_ASSERT_DECL(IS_POW2(DPDK_RING_SIZE));
> > --
> > 1.7.4.1
> >
> > _______________________________________________
> > dev mailing list
> > dev@openvswitch.org
> > http://openvswitch.org/mailman/listinfo/dev
_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev
