Question about scheduler framework interpodaffinity

Hi, everyone.
    I’m reading the kubernetes source code now to figure out scheduler framework plugin interpodaffinity performance problem under the large scale cluster (over thousand of nodes).
    I read the framework process PreFilterFilterPreScoreScore, and cannot understand some strange code cases. The plugin interpodaffinity PreScore function accept the score nodes []*framework.NodeInfo as parameters, but compute all allNodes from pl.sharedLister.NodeInfos()
    Here is code link PreScore .
    Hope someone could answer the question. Thanks!