Comment 3 for bug 1737465

This is a performance issue. Compute instances info just used by affinity filter.
Anti affinity will judgment the instance whether it belongs to the current computing node. The current code is to determine if the instance uuid is in the instances of the compute node.
We can determine if the current instance exists. If it exists, we get the host it belongs to. Then we judge in anti- affinity whether the host name of the compute node is the same as the instance host name.