PMD Load Balancing

OVS automatically collects task load statistics on each PMD polling core and measures their task processing pressure. This information is used to re-distribute tasks evenly across these PMD polling cores to balance single-core load pressure and avoid performance bottlenecks, thereby enhancing overall performance of the virtualization stack.

1. Determine whether to enable PMD load balancing.

   ovs-appctl dpif-netdev/pmd-rxq-show -secs 5

   

   You are advised to enable this optimization if a single PMD handles multiple workloads and the overhead usage exceeds 70%.

2. Configure OVS PMD load balancing.

   ovs-vsctl --no-wait set Open_vSwitch . \
   other_config:pmd-auto-lb="true" \
   other_config:pmd-auto-lb-improvement-threshold="25" \
   other_config:pmd-auto-lb-load-threshold="70" \
   other_config:pmd-auto-lb-rebal-interval="1"

   

   other_config:pmd-auto-lb="true" indicates that automatic load balancing is enabled.

   other_config:pmd-auto-lb-improvement-threshold="25" indicates that rebalancing is performed when the load variance reaches 25%.

   other_config:pmd-auto-lb-load-threshold="70" indicates that load balancing can be started when the PMD load reaches 70%.

   other_config:pmd-auto-lb-rebal-interval="1" indicates that the automatic load balancing interval is set to 1 minute.