GC Tuning Confessions of a Performance Engineer

Re:GC Tuning Confessions of a Performance Engineer by banachtarski on Friday May 29, 2015 @12:58PM (#9625752)

Comparing to malloc and free directly isn't very useful because that's pretty much the worst way to manage memory. Aside from memory arenas, you can just pool memory or preallocate too. I think concurrent data structures have very niche usage in practice (compared to say, a thread safe system).

>> cache line misses hurt.

> What does that have to do with GCs?

Everything. Sure you can use a copying GC and hope related objects go together. I tell the compiler to lump them together and exploit the prefetcher wherever possible.

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Re:GC Tuning Confessions of a Performance Engineer by pron on Saturday May 30, 2015 @04:26AM (#9629476)

> I tell the compiler to lump them together and exploit the prefetcher wherever possible.

That's a memory layout issue. What does a GC have to do with that? .NET and Go already allow good memory layout control, and Java will, too, once it gets value types. Conversely, one could create a manually-managed language that doesn't support object/array embedding, either. Memory layout control and GCs are completely orthogonal issues.

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