From: Sridhar Samudrala <sri@us.ibm.com>
To: Jason Wang <jasowang@redhat.com>
Cc: mst@redhat.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org, davem@davemloft.net,
krkumar2@in.ibm.com, rusty@rustcorp.com.au,
qemu-devel@nongnu.org, kvm@vger.kernel.org,
mirq-linux@rere.qmqm.pl
Subject: Re: [net-next RFC PATCH 0/7] multiqueue support for tun/tap
Date: Fri, 12 Aug 2011 17:46:30 -0700 [thread overview]
Message-ID: <1313196390.28682.14.camel@w-sridhar.beaverton.ibm.com> (raw)
In-Reply-To: <20110812015221.31613.95001.stgit@intel-e5620-16-2.englab.nay.redhat.com>
On Fri, 2011-08-12 at 09:54 +0800, Jason Wang wrote:
> As multi-queue nics were commonly used for high-end servers,
> current single queue based tap can not satisfy the
> requirement of scaling guest network performance as the
> numbers of vcpus increase. So the following series
> implements multiple queue support in tun/tap.
>
> In order to take advantages of this, a multi-queue capable
> driver and qemu were also needed. I just rebase the latest
> version of Krishna's multi-queue virtio-net driver into this
> series to simplify the test. And for multiqueue supported
> qemu, you can refer the patches I post in
> http://www.spinics.net/lists/kvm/msg52808.html. Vhost is
> also a must to achieve high performance and its code could
> be used for multi-queue without modification. Alternatively,
> this series can be also used for Krishna's M:N
> implementation of multiqueue but I didn't test it.
>
> The idea is simple: each socket were abstracted as a queue
> for tun/tap, and userspace may open as many files as
> required and then attach them to the devices. In order to
> keep the ABI compatibility, device creation were still
> finished in TUNSETIFF, and two new ioctls TUNATTACHQUEUE and
> TUNDETACHQUEUE were added for user to manipulate the numbers
> of queues for the tun/tap.
Is it possible to have tap create these queues automatically when
TUNSETIFF is called instead of having userspace to do the new
ioctls. I am just wondering if it is possible to get multi-queue
to be enabled without any changes to qemu. I guess the number of queues
could be based on the number of vhost threads/guest virtio-net queues.
Also, is it possible to enable multi-queue on the host alone without
any guest virtio-net changes?
Have you done any multiple TCP_RR/UDP_RR testing with small packet
sizes? 256byte request/response with 50-100 instances?
>
> I've done some basic performance testing of multi queue
> tap. For tun, I just test it through vpnc.
>
> Notes:
> - Test shows improvement when receving packets from
> local/external host to guest, and send big packet from guest
> to local/external host.
> - Current multiqueue based virtio-net/tap introduce a
> regression of send small packet (512 byte) from guest to
> local/external host. I suspect it's the issue of queue
> selection in both guest driver and tap. Would continue to
> investigate.
> - I would post the perforamnce numbers as a reply of this
> mail.
>
> TODO:
> - solve the issue of packet transmission of small packets.
> - addressing the comments of virtio-net driver
> - performance tunning
>
> Please review and comment it, Thanks.
>
> ---
>
> Jason Wang (5):
> tuntap: move socket/sock related structures to tun_file
> tuntap: categorize ioctl
> tuntap: introduce multiqueue related flags
> tuntap: multiqueue support
> tuntap: add ioctls to attach or detach a file form tap device
>
> Krishna Kumar (2):
> Change virtqueue structure
> virtio-net changes
>
>
> drivers/net/tun.c | 738 ++++++++++++++++++++++++++-----------------
> drivers/net/virtio_net.c | 578 ++++++++++++++++++++++++----------
> drivers/virtio/virtio_pci.c | 10 -
> include/linux/if_tun.h | 5
> include/linux/virtio.h | 1
> include/linux/virtio_net.h | 3
> 6 files changed, 867 insertions(+), 468 deletions(-)
>
next prev parent reply other threads:[~2011-08-13 0:46 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-12 1:54 [net-next RFC PATCH 0/7] multiqueue support for tun/tap Jason Wang
2011-08-12 1:54 ` [net-next RFC PATCH 1/7] tuntap: move socket/sock related structures to tun_file Jason Wang
2011-08-12 1:55 ` [net-next RFC PATCH 2/7] tuntap: categorize ioctl Jason Wang
2011-08-12 1:55 ` [net-next RFC PATCH 3/7] tuntap: introduce multiqueue related flags Jason Wang
2011-08-12 1:55 ` [net-next RFC PATCH 4/7] tuntap: multiqueue support Jason Wang
2011-08-12 14:29 ` Eric Dumazet
2011-08-14 6:05 ` Jason Wang
2011-08-12 23:21 ` Paul E. McKenney
2011-08-14 6:07 ` Jason Wang
2011-08-12 1:55 ` [net-next RFC PATCH 5/7] tuntap: add ioctls to attach or detach a file form tap device Jason Wang
2011-08-12 1:55 ` [net-next RFC PATCH 6/7] Change virtqueue structure Jason Wang
2011-08-12 1:55 ` [net-next RFC PATCH 7/7] virtio-net changes Jason Wang
2011-08-12 9:09 ` Sasha Levin
2011-08-14 5:59 ` Jason Wang
2011-08-17 13:24 ` WANG Cong
2011-08-12 2:11 ` [net-next RFC PATCH 0/7] multiqueue support for tun/tap Jason Wang
2011-08-13 0:46 ` Sridhar Samudrala [this message]
2011-08-14 6:19 ` Jason Wang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1313196390.28682.14.camel@w-sridhar.beaverton.ibm.com \
--to=sri@us.ibm.com \
--cc=davem@davemloft.net \
--cc=jasowang@redhat.com \
--cc=krkumar2@in.ibm.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mirq-linux@rere.qmqm.pl \
--cc=mst@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=qemu-devel@nongnu.org \
--cc=rusty@rustcorp.com.au \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).