What is cache coherency?

What is cache coherency?

Cache coherency refers to the consistency of data stored in local caches of a shared resource. It ensures that changes in one cache are reflected in others.

Why is cache coherency important in multi-core processors?

It's crucial because multiple cores may access shared data. Without coherency, one core might see stale data, leading to incorrect computations.

How do systems maintain cache coherency?

Systems use protocols like MESI (Modified, Exclusive, Shared, Invalid) to manage the state of cached data and ensure consistency.

What are the challenges in implementing cache coherency?

Challenges include increased complexity, potential performance bottlenecks, and the overhead of maintaining consistency across caches.

Can you give an example of a cache coherency protocol?

Sure! The MESI protocol is a common example, where each cache line can be in one of four states to manage data consistency.