Use of cache statistics to ration cache hierarchy access
A method, system and program are provided for controlling access to a specified cache level in a cache hierarchy in a multiprocessor system by evaluating cache statistics for a specified application at the specified cache level against predefined criteria to prevent the specified application from accessing the specified cache level if the specified application does not meeting the predefined criteria.
1. A method for controlling access to a cache hierarchy, comprising:
collecting cache statistics for a plurality of applications at every cache level of a multi-level cache using a hardware counter to periodically collect statistics on data cache misses, hits, and references for every level of the multi-level cache;
evaluating the cache statistics for each of the plurality of applications against a predefined activity threshold for a victim cache level which is only populated with cast-offs from a higher level of the multi-level cache;
preventing access to the victim cache level by a cache line from any application from the plurality of applications that does not meet the predefined activity threshold for the victim cache level; and
moving the cache line from said application to a cache level below the victim cache level in the multi-level cache.