On Tue, Sep 27, 2016 at 10:42:49AM +0200, Maxime Coquelin 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 at redhat.com>
Applied to dpdk-next-virtio.
Thanks.
--yliu
