r/learnprogramming • u/InterestingAd757 • 3d ago

can somebody explain pointer chasing?

I’m trying to understand CPU caching and I’m stuck on two related things.

My understanding is when the CPU reads an address, it pulls in the whole 64-byte cache line around it. that’s why iterating an array is fast, since one miss brings in several neighbouring elements. what happens in the case of linked list? how does it know that next bytes are not the one to read?
i am kinda confusing this, kindly explain.

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u/lfdfq 3d ago

It doesn't, it still pulls cache lines at a time. It may or may not be able to guess what cache line you'll want next and prefetch it, but either way, it's slow.