GPU621/Group 1

What is Flase Sharing?(Introduction)

Multicore programming is important to take advantage of the hardware's power as multicore processors are more common than ever. This is because it enables us to run our code on various CPU cores. But in order to effectively utilise it, it is crucial to know and comprehend the underlying hardware. The cache is one of the most crucial system tools. The majority of designs also have shared cache lines. And for this reason, false sharing in multicore/multithreaded tasks is a well-known issue. What is cache line ping-ponging, also known as false sharing? When multiple threads exchange data, one of the sharing patterns that has an impact on performance is false sharing. It occurs when at least two threads alter or use data that is in near proximity to one another in memory.

When multiple threads exchange data, one of the sharing patterns that has an impact on performance is false sharing. When at least two threads change or use data that just so happens to be nearby in memory and ends up in the same cache line, it causes this problem. False sharing happens when they frequently change their individual data in such a way that the cache line switches back and forth between the caches of two different threads.

Sources

https://learn.microsoft.com/en-us/archive/msdn-magazine/2008/october/net-matters-false-sharing

http://www.nic.uoregon.edu/~khuck/ts/acumem-report/manual_html/multithreading_problems.html

https://www.baeldung.com/java-false-sharing-contended#:~:text=In%20the%20MESI%20protocol%2C%20each,the%20acronym%20of%20these%20states

https://levelup.gitconnected.com/false-sharing-the-lesser-known-performance-killer-bbb6c1354f07

https://www.easytechjunkie.com/what-is-false-sharing.htm