Numa Collectors in Hotspot

Aleksey Shipilev shade at
Tue Sep 26 16:14:14 UTC 2017

On 09/26/2017 06:08 PM, Hohensee, Paul wrote:
> For G1, see also
> At Amazon, we have use cases where we’d prefer to use G1 heaps that exceed the size of the memory
> attached to a single socket on NUMA systems. Without G1 recognition and use of UseNUMA, we’re
> forced to use multiple single-socket JVMs and consolidate their results, which is (a) more
> complex to implement, and (b) slower than we’d like. Enhancing G1 to recognize and use UseNUMA
> would be a win for us.

Testing Shenandoah on large NUMA machines, we have the experience of piggy-backing on first-touch
policy when you supply AlwaysPreTouch. When collector does the memory pretouch in multithreaded
mode, this seems to give you interleaving approximation without exact GC support.

My 2c.


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