From: "Michael S. Tsirkin" <mst@redhat.com>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Khoa Huynh <khoa@us.ibm.com>, qemu-devel@nongnu.org
Subject: [Qemu-devel] Re: [PATCH v5 0/4] virtio: Use ioeventfd for virtqueue notify
Date: Thu, 6 Jan 2011 20:00:31 +0200 [thread overview]
Message-ID: <20110106180031.GB28917@redhat.com> (raw)
In-Reply-To: <AANLkTinxEbZnmFcM7z4=5b=FnRDFdOY3O9Tt6eMactOY@mail.gmail.com>
On Thu, Jan 06, 2011 at 04:41:50PM +0000, Stefan Hajnoczi wrote:
> Here are 4k sequential read results (cache=none) to check whether we
> see an ioeventfd performance regression with virtio-blk.
>
> The idea is to use a small blocksize with an I/O pattern (sequential
> reads) that is cheap and executes quickly. Therefore we're doing many
> iops and the cost virtqueue kick/notify is especially important.
> We're not trying to stress the disk, we're trying to make the
> difference in ioeventfd=on/off apparent.
>
> I did 2 runs for both ioeventfd=off and ioeventfd=on. The results are
> similar: 1% and 2% degradation in MB/s or iops. We'd have to do more
> runs to see if the degradation is statistically significant, but the
> percentage value is so low that I'm satisfied.
>
> Are you happy to merge virtio-ioeventfd v6 + your fixups?
BTW if you could do some migration stress-testing too,
would be nice. autotest has support for it now.
--
MST
next prev parent reply other threads:[~2011-01-06 18:00 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-12 15:02 [Qemu-devel] [PATCH v5 0/4] virtio: Use ioeventfd for virtqueue notify Stefan Hajnoczi
2010-12-12 15:02 ` [Qemu-devel] [PATCH v5 1/4] virtio-pci: Rename bugs field to flags Stefan Hajnoczi
2010-12-12 15:02 ` [Qemu-devel] [PATCH v5 2/4] virtio-pci: Use ioeventfd for virtqueue notify Stefan Hajnoczi
2011-01-24 18:54 ` Kevin Wolf
2011-01-24 19:36 ` Michael S. Tsirkin
2011-01-24 19:48 ` Kevin Wolf
2011-01-24 19:47 ` Michael S. Tsirkin
2011-01-24 20:05 ` Kevin Wolf
2011-01-25 7:12 ` Stefan Hajnoczi
2011-01-25 9:49 ` Stefan Hajnoczi
2011-01-25 9:54 ` Stefan Hajnoczi
2011-01-25 11:27 ` Michael S. Tsirkin
2011-01-25 13:20 ` Stefan Hajnoczi
2011-01-25 14:07 ` Stefan Hajnoczi
2011-01-25 19:18 ` Anthony Liguori
2011-01-25 19:45 ` Stefan Hajnoczi
2011-01-25 19:51 ` Anthony Liguori
2011-01-25 19:59 ` Stefan Hajnoczi
2011-01-26 0:18 ` Anthony Liguori
2010-12-12 15:02 ` [Qemu-devel] [PATCH v5 3/4] virtio-pci: Don't use ioeventfd on old kernels Stefan Hajnoczi
2010-12-12 15:02 ` [Qemu-devel] [PATCH v5 4/4] docs: Document virtio PCI -device ioeventfd=on|off Stefan Hajnoczi
2010-12-12 15:14 ` [Qemu-devel] Re: [PATCH v5 0/4] virtio: Use ioeventfd for virtqueue notify Stefan Hajnoczi
2010-12-12 20:41 ` Michael S. Tsirkin
2010-12-12 20:42 ` Michael S. Tsirkin
2010-12-12 20:56 ` Michael S. Tsirkin
2010-12-12 21:09 ` Michael S. Tsirkin
2010-12-13 10:24 ` Stefan Hajnoczi
2010-12-13 10:38 ` Michael S. Tsirkin
2010-12-13 13:11 ` Stefan Hajnoczi
2010-12-13 13:35 ` Michael S. Tsirkin
2010-12-13 13:36 ` Michael S. Tsirkin
2010-12-13 14:06 ` Stefan Hajnoczi
2010-12-13 15:27 ` Stefan Hajnoczi
2010-12-13 16:00 ` Michael S. Tsirkin
2010-12-13 16:29 ` Stefan Hajnoczi
2010-12-13 16:30 ` Michael S. Tsirkin
2010-12-13 16:12 ` Michael S. Tsirkin
2010-12-13 16:28 ` Stefan Hajnoczi
2010-12-13 17:57 ` Stefan Hajnoczi
2010-12-13 18:52 ` Michael S. Tsirkin
2010-12-15 11:42 ` Stefan Hajnoczi
2010-12-15 11:48 ` Stefan Hajnoczi
2010-12-15 12:00 ` Michael S. Tsirkin
2010-12-15 12:14 ` Michael S. Tsirkin
2010-12-15 12:59 ` Stefan Hajnoczi
2010-12-16 16:40 ` Stefan Hajnoczi
2010-12-16 23:39 ` Michael S. Tsirkin
2010-12-19 14:49 ` Michael S. Tsirkin
2011-01-06 16:41 ` Stefan Hajnoczi
2011-01-06 17:04 ` Michael S. Tsirkin
2011-01-06 18:00 ` Michael S. Tsirkin [this message]
2011-01-07 8:56 ` Stefan Hajnoczi
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=20110106180031.GB28917@redhat.com \
--to=mst@redhat.com \
--cc=khoa@us.ibm.com \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@gmail.com \
/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).