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From: Rick Jones <rick.jones2@hp.com>
To: Qin Chuanyu <qinchuanyu@huawei.com>,
	"Michael S. Tsirkin" <mst@redhat.com>
Cc: jasowang@redhat.com, Anthony Liguori <anthony@codemonkey.ws>,
	KVM list <kvm@vger.kernel.org>,
	netdev@vger.kernel.org
Subject: Re: 8% performance improved by change tap interact with kernel stack
Date: Tue, 28 Jan 2014 08:56:34 -0800	[thread overview]
Message-ID: <52E7E142.8000407@hp.com> (raw)
In-Reply-To: <52E77506.1080604@huawei.com>

On 01/28/2014 01:14 AM, Qin Chuanyu wrote:
> On 2014/1/28 16:34, Michael S. Tsirkin wrote:
>> Could you please check latency results?
>>
> netperf UDP_RR 512
> test model: VM->host->host
>
> modified before : 11108
> modified after  : 11480
>
> 3% gained by this patch

Netperf UDP_RR can be very sensitive to packet losses.  Not that there 
were necessarily any in your tests, but to further confirm the 3% 
improvement in latency, I would suggest using the confidence intervals 
functionality in your before/after netperf testing.  And to get at what 
Michael asks about CPU utilization I would suggest:

netperf -H <otherguy> -c -C -l 30 -i 30,3 -t UDP_RR -- -r 512

(I was guessing as to what netperf options you may have been using already)

happy benchmarking,

rick jones


  parent reply	other threads:[~2014-01-28 16:56 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-28  8:14 8% performance improved by change tap interact with kernel stack Qin Chuanyu
2014-01-28  8:34 ` Michael S. Tsirkin
2014-01-28  9:14   ` Qin Chuanyu
2014-01-28  9:41     ` Michael S. Tsirkin
2014-01-28 10:19       ` Qin Chuanyu
2014-01-28 10:33         ` Michael S. Tsirkin
2014-01-28 16:58           ` Stephen Hemminger
2014-01-28 17:18             ` Michael S. Tsirkin
2014-01-29  7:41           ` Qin Chuanyu
2014-01-29  7:56             ` Michael S. Tsirkin
2014-01-28 16:56     ` Rick Jones [this message]
2014-01-28 14:49 ` Eric Dumazet
2014-01-29  7:12   ` Qin Chuanyu
2014-02-11 13:21   ` Qin Chuanyu

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