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Vlad Yasevich authored
Macvlan currently inherits all of its features from the lower device. When lower device disables offload support, this causes macvlan to disable offload support as well. This causes performance regression when using macvlan/macvtap in bridge mode. It can be easily demonstrated by creating 2 namespaces using macvlan in bridge mode and running netperf between them: MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.0.0.1 () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 20.00 1204.61 To restore the performance, we add software offload features to the list of "always_on" features for macvlan. This way when a namespace or a guest using macvtap initially sends a packet, this packet will not be segmented at macvlan level. It will only be segmented when macvlan sends the packet to the lower device. MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.0.0.1 () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 20.00 5507.35 Fixes: 6acf54f1 (macvtap: Add support of packet capture on macvtap device.) Fixes: 797f87f8 (macvlan: fix netdev feature propagation from lower device) CC: Florian Westphal <fw@strlen.de> CC: Christian Borntraeger <borntraeger@de.ibm.com> CC: Jason Wang <jasowang@redhat.com> CC: Michael S. Tsirkin <mst@redhat.com> Tested-by:
Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by:
Vlad Yasevich <vyasevic@redhat.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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