Minor Description
https://github.com/apache/spark/commit/a1f0992faefbe042a9cb7a11842a817c958e4797#diff-fa4cfb2cce1b925f55f41f2dfa8c8501R61 should be || not &&
As written now, there must be both memory and disk bytes spilled to show either of them. If there is only one of those types of spill recorded, it will be hidden.
