When Plasma evicts objects on running out of memory, it prints log messages of the form:
There is not enough space to create this object, so evicting x objects to free up y bytes. The number of bytes in use (before this eviction) is z.
However, the reported number of bytes in use (before this eviction) actually reports the number of bytes after the eviction. A straightforward fix is to simply replace z with (y+z).