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@xxxxxxxxx> 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. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
