From: "Michael S. Tsirkin" <mst@redhat.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>,
yuanhan.liu@linux.intel.com, huawei.xie@intel.com, dev@dpdk.org,
vkaplans@redhat.com
Subject: Re: [dpdk-dev] [PATCH v2] vhost: Add indirect descriptors support to the TX path
Date: Fri, 23 Sep 2016 21:31:27 +0300 [thread overview]
Message-ID: <20160923213055-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20160923112416.4f798b4b@xeon-e3>
On Fri, Sep 23, 2016 at 11:24:16AM -0700, Stephen Hemminger wrote:
> On Fri, 23 Sep 2016 09:16:49 +0200
> Maxime Coquelin <maxime.coquelin@redhat.com> wrote:
>
> > Indirect descriptors are usually supported by virtio-net devices,
> > allowing to dispatch a larger number of requests.
> >
> > When the virtio device sends a packet using indirect descriptors,
> > only one slot is used in the ring, even for large packets.
> >
> > The main effect is to improve the 0% packet loss benchmark.
> > A PVP benchmark using Moongen (64 bytes) on the TE, and testpmd
> > (fwd io for host, macswap for VM) on DUT shows a +50% gain for
> > zero loss.
> >
> > On the downside, micro-benchmark using testpmd txonly in VM and
> > rxonly on host shows a loss between 1 and 4%.i But depending on
> > the needs, feature can be disabled at VM boot time by passing
> > indirect_desc=off argument to vhost-user device in Qemu.
> >
> > Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>
> What about supporting VIRTIO_F_ANY_LAYOUT?
I thought it's already supported.
That's required by virtio 1 and dpdk claims support for that.
--
MST
next prev parent reply other threads:[~2016-09-23 18:31 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-23 7:16 Maxime Coquelin
2016-09-23 7:29 ` Yuanhan Liu
2016-09-23 7:33 ` Maxime Coquelin
2016-09-23 18:24 ` Stephen Hemminger
2016-09-23 18:31 ` Michael S. Tsirkin [this message]
2016-09-23 20:28 ` Stephen Hemminger
2016-09-25 1:02 ` Michael S. Tsirkin
2016-09-25 1:50 ` Stephen Hemminger
2016-09-25 1:53 ` Michael S. Tsirkin
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