Tracking the content of a cache

Abstract

The invention relates to tracking the content of a cache. The cache is provided comprising a plurality of ways, each way of the plurality of ways comprising a data array, wherein a data item stored by the cache is stored in the data array of one of the plurality of ways. A way tracker of the cache has a plurality of entries, each entry of the plurality of entries for storing a data item identifier and for storing, in association with the data item identifier, an indication of a selected way of the plurality of ways to indicate that a data item identified by the data item identifier is stored in the selected way. Each entry of the way tracker is further for storing a miss indicator in association with the data item identifier, wherein the miss indicator is set by the cache when a lookup for a data item identified by that data item identifier has resulted in a cache miss. A corresponding method of caching data is also provided.

Description

technical field [0001] This disclosure relates to data processing. More specifically, the present disclosure relates to caching data for data processing. Background technique [0002] A cache may be provided in the data processing apparatus to store local copies of data items stored in the memory so that when those data items are frequently accessed by the data processing apparatus, it is not necessary to cause and retrieve those data items from the memory for each access The delay associated with the item. [0003] The cache may be provided in the form of multiple levels of cache, where the levels of cache and the memory for storing data items form a hierarchy, with smaller and faster caches being provided closer to the processing elements of the data processing device, and larger and slower ones being provided closer to the memory. cache. [0004] Caches can be arranged in a set-associative fashion, where multiple paths are provided that can be used to store data items....

AI Technical Summary

Problems solved by technology

If there is only one possible storage location in the cache for these two data items, accessing one data item will evict the other data item, and frequent accesses to both data items will cause "thrashing"

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