Messages in this thread | | | Date | Thu, 27 Feb 2014 21:52:22 +0100 | From | Christian Borntraeger <> | Subject | macvtap performance regression (bisected) between 3.13 and 3.14-rc1 |
| |
Vlad,
commit 6acf54f1cf0a6747bac9fea26f34cfc5a9029523 macvtap: Add support of packet capture on macvtap device.
causes a performance regression for iperf traffic between two KVM guests on my s390 system. Both guests are connected via two macvtaps on the same OSA network card. Before that patch I get ~20 Gbit/sec between two guests, afterwards I get ~4Gbit/sec
Latency seems to be unchanges (uperf 1byte ping pong).
According to ifconfig in the guest, I have ~ 1500 bytes per packet with this patch and ~ 40000 bytes without. So for some reason this patch causes the network stack to do segmentation. (the guest kernel stays the same, only host kernel is changed).
Any ideas?
Christian
| |