From: Anthony Liguori <aliguori@us.ibm.com>
To: Ben-Ami Yassour <benami@il.ibm.com>
Cc: kvm@vger.kernel.org, markmc@redhat.com,
Muli Ben-Yehuda <MULI@il.ibm.com>
Subject: Re: virtio performance issue
Date: Tue, 16 Sep 2008 09:16:38 -0500 [thread overview]
Message-ID: <48CFBFC6.4040405@us.ibm.com> (raw)
In-Reply-To: <1221574441.26630.19.camel@cluwyn.haifa.ibm.com>
Ben-Ami Yassour wrote:
> I am running virtio with the latest KVM code, and see a significant
> performance issue.
>
> Ping to the host (or any other close machine) reports a 4ms delay.
>
What kvm version and what host kernel version?
It's very easy to mistakenly compile qemu without GSO support too. You
have to make sure that the 2.6.27 if_tun.h is being included by QEMU.
Regards,
Anthony Liguori
> In the same setup with an e1000 emulation (just changing model=virtio to
> model=e1000 in the KVM command line), ping reports 0.177ms delay.
>
> BTW, initially I saw that the throughput when using netperf is very low,
> even from guest to host, even though the CPU utilization is low.
>
> What might be the problem?
>
> Thanks,
> Ben
>
>
next prev parent reply other threads:[~2008-09-16 14:17 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-16 14:14 virtio performance issue Ben-Ami Yassour
2008-09-16 14:16 ` Anthony Liguori [this message]
2008-09-16 19:24 ` Ben-Ami Yassour
2008-09-17 10:49 ` Mark McLoughlin
2008-09-17 12:10 ` Ben-Ami Yassour
2008-09-16 17:43 ` Bernhard Schmidt
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