Messages in this thread | | | Subject | Re: [RFC PATCH v9 00/16] Provide a zero-copy method on KVM virtio-net. | From | Shirley Ma <> | Date | Tue, 10 Aug 2010 23:55:04 -0700 |
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On Tue, 2010-08-10 at 23:01 -0700, Shirley Ma wrote: > On Tue, 2010-08-10 at 18:43 -0700, Shirley Ma wrote: > > > Also I found some vhost performance regression on the new > > > kernel with tuning. I used to get 9.4Gb/s, now I couldn't get it. > > > > I forgot to mention the kernel I used 2.6.36 one. And I found the > > native > > host BW is limited to 8.0Gb/s, so the regression might come from the > > device driver not vhost. > > Something is very interesting, when binding ixgbe interrupts to cpu1, > and running netperf/netserver on cpu0, the native host to host > performance is still around 8.0Gb/s, however, the macvtap zero copy > result is 9.0Gb/s. > > root@localhost ~]# netperf -H 192.168.10.74 -c -C -l60 -T0,0 -- -m 64K > TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.74 (192.168.. > 10.74) port 0 AF_INET : cpu bind > 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 % S us/KB us/KB > > 87380 16384 65536 60.00 9013.59 53.01 8.21 0.963 0.597 > > Below is perf top output: > > 578.00 6.5% copy_user_generic_string > 381.00 4.3% vmx_vcpu_run > 250.00 2.8% schedule > 207.00 2.3% vhost_get_vq_desc > 204.00 2.3% _raw_spin_lock_irqsave > 197.00 2.2% translate_desc > 193.00 2.2% memcpy_fromiovec > 162.00 1.8% gup_pte_range > > We can compare your results with mine to see any difference.
When binding vhost thread to cpu3, qemu I/O thread to cpu2, macvtap zero copy patch can get 9.4Gb/s.
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.74 (192.168.10.74) port 0 AF_INET : cpu bind 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 % S us/KB us/KB
87380 16384 65536 60.00 9408.19 55.69 8.45 0.970 0.589
Shirley
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