From: Gleb Natapov <gleb@redhat.com>
To: "George-Cristian Bîrzan" <gc@birzan.org>
Cc: kvm@vger.kernel.org
Subject: Re: Performance issue
Date: Sun, 25 Nov 2012 17:19:50 +0200 [thread overview]
Message-ID: <20121125151949.GD25516@redhat.com> (raw)
In-Reply-To: <CAMxNYaY-S6HCkiEfyP3kHq9_BPstV+kG8Hfvj3-5t9CAVa-_hA@mail.gmail.com>
On Thu, Nov 22, 2012 at 09:17:34PM +0200, George-Cristian Bîrzan wrote:
> I'm trying to understand a performance problem (50% degradation in the
> VM) that I'm experiencing some systems with qemu-kvm. Running Fedora
> with 3.5.3-1.fc17.x86_64 or 3.6.6-1.fc17.x86_64, qemu 1.0.1 or 1.2.1
> on AMD Opteron 6176 and 6174, and all of them behave identically.
>
> A Windows guest is receiving a UDP MPEG stream that is being processed
> by TSReader. The stream comes in at about 73Mbps, but the VM cannot
> process more than 43Mbps. It's not a networking issue, the packets
> reach the guest and with iperf we can easily do 80Mbps. Also, with
> iperf, it can receive the packets from the streamer (even though it
> doesn't detect things properly, but it was just a way to see ).
>
> However, on an identical host (a 6174 CPU, even), a Windows install
> has absolutely no problem processing the same stream.
>
What Windows is this? Can you try changing "-cpu host" to "-cpu
host,+hv_relaxed"?
--
Gleb.
next prev parent reply other threads:[~2012-11-25 15:19 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-22 19:17 Performance issue George-Cristian Bîrzan
2012-11-23 7:26 ` Stefan Hajnoczi
[not found] ` <CAMxNYabWpHqmNN7mCY9mwVJjoTj4jwS_js+cZcxQVnJsTdwfBg@mail.gmail.com>
2012-11-23 14:02 ` Fwd: " George-Cristian Bîrzan
2012-11-25 15:19 ` Gleb Natapov [this message]
2012-11-25 16:17 ` George-Cristian Bîrzan
2012-11-26 19:31 ` George-Cristian Bîrzan
2012-11-27 12:20 ` Gleb Natapov
2012-11-27 12:29 ` George-Cristian Bîrzan
2012-11-27 14:54 ` Gleb Natapov
2012-11-27 20:38 ` Vadim Rozenfeld
2012-11-27 21:13 ` George-Cristian Bîrzan
2012-11-28 11:39 ` Vadim Rozenfeld
2012-11-28 19:09 ` George-Cristian Bîrzan
2012-11-29 11:56 ` Vadim Rozenfeld
2012-11-29 13:45 ` George-Cristian Bîrzan
2012-11-29 13:56 ` Gleb Natapov
2012-11-29 20:34 ` Vadim Rozenfeld
2012-11-28 19:18 ` George-Cristian Bîrzan
2012-11-28 19:56 ` Gleb Natapov
2012-11-28 20:01 ` George-Cristian Bîrzan
2012-11-28 20:12 ` Gleb Natapov
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