From: Sasha Levin <levinsasha928@gmail.com>
To: Asias He <asias.hejun@gmail.com>
Cc: Pekka Enberg <penberg@kernel.org>,
john@jfloren.net, kvm@vger.kernel.org, mingo@elte.hu,
gorcunov@gmail.com, prasadjoshi124@gmail.com
Subject: Re: [PATCH v2 3/4] kvm tools: Use ioeventfd in virtio-net
Date: Wed, 01 Jun 2011 09:35:51 +0300 [thread overview]
Message-ID: <1306910151.2929.7.camel@lappy> (raw)
In-Reply-To: <4DE598DC.90502@gmail.com>
On Wed, 2011-06-01 at 09:41 +0800, Asias He wrote:
> On 06/01/2011 12:32 AM, Sasha Levin wrote:
> > On Tue, 2011-05-31 at 10:18 +0300, Pekka Enberg wrote:
> >> On Tue, May 31, 2011 at 2:53 AM, Asias He <asias.hejun@gmail.com> wrote:
> >>> TAP based network performance with ioeventfd
> >>
> >> Heh, so how did it look _before_ ioeventfd? Did performance improve
> >> and how much?
> >
> > Asias, did you use TCP or UDP values as bandwidth in your previous test?
> >
>
> These commit log have the performance test result before ioeventfd. But
> the UDP one is missing.
>
> commit 739ddbb3b0fe52aa90a84727a6e90da37ce7661b
> commit 4ed38b41fc034cfb51fec2004f523fe98faa27f6
>
>
> Netpef test shows this patch changes:
>
> the host to guest bandwidth
> from 2866.27 Mbps (cpu 33.96%) to 5548.87 Mbps (cpu 53.87%),
>
> the guest to host bandwitdth
> form 1408.86 Mbps (cpu 99.9%) to 1301.29 Mbps (cpu 99.9%).
>
>
> Anyway, I did another test and post the result here:
>
> Test shows host -> guest TCP performance drops from 6736.04 to 5562.25.
> guest -> host TCP performance dumps from 1572.51 to 1731.55.
That's quite strange. I wasn't expecting any changes with our current
network code: Our RX thread is blocking on readv() most of the time, so
it doesn't get affected by IRQ/ioeventfd signals at all, and the TX
thread should get signaled to wake up just once or twice when the stream
starts - after which the virtio ring should be full with data.
I installed netperf and ran the tests (full results are below), guest ->
host TCP changed from 1862 to 2567 and host -> guest TCP changed from
7716 to 8065.
----------
Before ioeventfd:
(guest -> host)
tux ~ # netperf -c -t TCP_STREAM -H 192.168.33.2
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.33.2
(192.168.33.2) port 0 AF_INET
Recv Send Send Utilization Service
Demand
Socket Socket Message Elapsed Send Recv Send
Recv
Size Size Size Time Throughput local remote local
remote
bytes bytes bytes secs. 10^6bits/s % S % U us/KB
us/KB
87380 16384 16384 10.00 1862.98 49.75 -1.00 4.375
-1.000
tux ~ # netperf -c -t UDP_STREAM -H 192.168.33.2
UDP UNIDIRECTIONAL SEND TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
192.168.33.2 (192.168.33.2) port 0 AF_INET
Socket Message Elapsed Messages CPU
Service
Size Size Time Okay Errors Throughput Util Demand
bytes bytes secs # # 10^6bits/sec % SU us/KB
124928 65507 10.00 301117 0 15779.9 43.13 0.449
124928 10.00 300118 15727.6 -1.00 -1.000
(host -> guest)
lappy ~ # netperf -c -t TCP_STREAM -H 192.168.33.4
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.33.4
(192.168.33.4) port 0 AF_INET
Recv Send Send Utilization Service
Demand
Socket Socket Message Elapsed Send Recv Send
Recv
Size Size Size Time Throughput local remote local
remote
bytes bytes bytes secs. 10^6bits/s % S % U us/KB
us/KB
87380 16384 16384 10.00 7716.23 87.49 -1.00 1.858
-1.000
lappy ~ # netperf -c -t UDP_STREAM -H 192.168.33.4
UDP UNIDIRECTIONAL SEND TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
192.168.33.4 (192.168.33.4) port 0 AF_INET
Socket Message Elapsed Messages CPU
Service
Size Size Time Okay Errors Throughput Util Demand
bytes bytes secs # # 10^6bits/sec % SU us/KB
124928 65507 10.00 142037 0 7443.4 84.34 6.398
124928 10.00 41211 2159.6 -1.00 -1.000
After ioeventfd:
(guest -> host)
tux ~ # netperf -c -t TCP_STREAM -H 192.168.33.2
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.33.2
(192.168.33.2) port 0 AF_INET
Recv Send Send Utilization Service
Demand
Socket Socket Message Elapsed Send Recv Send
Recv
Size Size Size Time Throughput local remote local
remote
bytes bytes bytes secs. 10^6bits/s % S % U us/KB
us/KB
87380 16384 16384 10.00 2567.83 47.29 -1.00 3.017
-1.000
tux ~ # netperf -c -t UDP_STREAM -H 192.168.33.2
UDP UNIDIRECTIONAL SEND TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
192.168.33.2 (192.168.33.2) port 0 AF_INET
Socket Message Elapsed Messages CPU
Service
Size Size Time Okay Errors Throughput Util Demand
bytes bytes secs # # 10^6bits/sec % SU us/KB
124928 65507 10.00 305265 0 15997.4 49.35 0.506
124928 10.00 304818 15974.0 -1.00 -1.000
(host -> guest)
lappy ~ # netperf -c -t TCP_STREAM -H 192.168.33.4
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.33.4
(192.168.33.4) port 0 AF_INET
Recv Send Send Utilization Service
Demand
Socket Socket Message Elapsed Send Recv Send
Recv
Size Size Size Time Throughput local remote local
remote
bytes bytes bytes secs. 10^6bits/s % S % U us/KB
us/KB
87380 16384 16384 10.00 8065.82 88.15 -1.00 1.791
-1.000
lappy ~ # netperf -c -t UDP_STREAM -H 192.168.33.4
UDP UNIDIRECTIONAL SEND TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
192.168.33.4 (192.168.33.4) port 0 AF_INET
Socket Message Elapsed Messages CPU
Service
Size Size Time Okay Errors Throughput Util Demand
bytes bytes secs # # 10^6bits/sec % SU us/KB
124928 65507 10.00 137846 0 7223.8 83.97 6.540
124928 10.00 40140 2103.5 -1.00 -1.000
--
Sasha.
next prev parent reply other threads:[~2011-06-01 6:36 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-27 16:18 [PATCH v2 1/4] kvm tools: Add ioeventfd support Sasha Levin
2011-05-27 16:18 ` [PATCH v2 2/4] kvm tools: Use ioeventfd in virtio-blk Sasha Levin
2011-05-27 16:18 ` [PATCH v2 3/4] kvm tools: Use ioeventfd in virtio-net Sasha Levin
2011-05-29 12:51 ` Ingo Molnar
2011-05-30 23:53 ` Asias He
2011-05-31 7:18 ` Pekka Enberg
2011-05-31 16:32 ` Sasha Levin
2011-06-01 1:41 ` Asias He
2011-06-01 6:35 ` Sasha Levin [this message]
2011-06-01 11:11 ` Asias He
2011-05-27 16:18 ` [PATCH v2 4/4] kvm tools: Use ioeventfd in virtio-rng Sasha Levin
2011-05-27 16:52 ` [PATCH v2 1/4] kvm tools: Add ioeventfd support Ingo Molnar
2011-05-29 11:55 ` Pekka Enberg
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