Methods and systems consistent with this invention conserve computer resources
in a hierarchical memory system by preventing scratch data from unnecessarily being
copied from a lower hierarchy to a higher hierarchy storage space. Such methods
and systems invalidate portions of data in the higher hierarchy storage space so
that the coherence protocol does not copy the data to the lower hierarchy storage
space. For example, methods and systems consistent with this invention hierarchically
store data in a computer system having a main memory and a cache memory. Such methods
and systems designate an area of the cache memory that contains scratch data as
invalid, wherein the invalid data occupies less space than a maximum space of the
cache memory, and permit a writing over of the invalid data in the cache memory.
