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Myths Programmers Believe about CPU Caches (2018)

(software.rajivprab.com)
149 points whack | 1 comments | 31 Oct 25 00:46 UTC | HN request time: 0s | source
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groundzeros2015 ◴[01 Nov 25 12:03 UTC] No.45780994[source]▶
Did this article share more than one myth?

The reason why programmers don’t believe in cache coherency is because they have experienced a closely related phenomena, memory reordering. This requires you to use a memory fence when accessing a shared value between multiples cores - as if they needed to synchronize.

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igtztorrero ◴[01 Nov 25 13:41 UTC] No.45781571[source]▶
In Golang there are sync.Mutex, sync.Atomic and Channels to create this fence and prevent data races. I prefer sync.Mutex.

Does anyone understand how Go handles the CPU cache?

replies(1): >>45783554 #
groundzeros2015 ◴[01 Nov 25 17:34 UTC] No.45783554[source]▶
Yes. Locks will use a memory fence. More advanced programs will need fence without locking.
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1. ◴[01 Nov 25 19:28 UTC] No.45784556[source]▶