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From: Xupeng Yun <recordus@gmail.com>
To: Avi Kivity <avi@redhat.com>
Cc: kvm@vger.kernel.org
Subject: Re: High latency with VirtIO NIC
Date: Thu, 24 Mar 2011 21:45:03 +0800	[thread overview]
Message-ID: <76F180B5B89249CDA99A9521558BAF11@gmail.com> (raw)
In-Reply-To: <4D8B1B4F.5070305@redhat.com>


On Thursday, March 24, 2011 at 6:22 PM, Avi Kivity wrote:
Try vhost-net, that should have much better latencies.
>  Indeed, the latency is much better after switching to vhost-net, it drops from 3+ms to ~1.5ms on average
when there is no network load on the KVM guest, but the latencies become bad again when there is 
heavy network load on the guest(~70Mbps RX and ~25Mbps TX).

--------------------------- ping KVM guest (app211) from the host ---------------------------
64 bytes from app211 (192.168.1.211): icmp_seq=3582 ttl=64 time=3.08 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3583 ttl=64 time=1.10 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3584 ttl=64 time=1.03 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3585 ttl=64 time=3.55 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3586 ttl=64 time=1.29 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3587 ttl=64 time=0.710 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3588 ttl=64 time=64.4 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3589 ttl=64 time=0.271 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3590 ttl=64 time=0.563 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3591 ttl=64 time=1.66 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3592 ttl=64 time=0.939 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3593 ttl=64 time=0.819 ms
64 bytes from app211 (192.168.1.211): icmp_seq=3594 ttl=64 time=16.5 ms

--------------------------- ping KVM guest (app211) from the host ---------------------------

any idea?

Thanks,
Xupeng




  reply	other threads:[~2011-03-24 13:45 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-24  0:37 High latency with VirtIO NIC Xupeng Yun
2011-03-24 10:22 ` Avi Kivity
2011-03-24 13:45   ` Xupeng Yun [this message]
2011-03-24 13:50     ` Xupeng Yun
2011-03-24 14:08     ` Avi Kivity
2011-03-24 14:24       ` Xupeng Yun
2011-03-24 14:27         ` Avi Kivity
2011-03-24 14:34           ` Xupeng Yun

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