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=== What is a Cache? ===

Before we can talk about false sharing, we need a brief overview of a cache. Like other storage mediums, a cache is a place used to store data and instructions that the CPU may use.

=== Cache Coherence and Cache Line ===

Each processor has their own local cache. When data is needed, a fixed block of memory is transferred to the cache; this block is known as a cache line.

Identifying false sharing requires detailed code inspection as everything will appear to work normally on the surface. However, when left unchecked false sharing will be detrimental to the program's performance and scalability. This article discussed the relation between the cache and false sharing. In addition, using a simple example, we explained how you can use padding, synchronization, and thread local variables to reduce the frequency of false sharing.