jcmd VM.native_memory extremely large numbers when using ZGC

[Florian Weimer]

* Marçal Perapoch Amadó:

>> As in, Java OOMEs? OOM killer? Or the pod being killed from the pod management?

> Our canary pods using ZGC were OOM killed, yes. It's also visible in
> our metrics how the "container_memory_working_set_bytes" of the pods
> using zgc went above 20GB even though they were set to use a max heap
> of 6GB.

I think some container hosts kill processes based on RSS alone, so even
memory-mapped I/O can trigger this.  From the hosts perspective, it
doesn't matter if the memory is just used for caching and could be
discarded any time because it's a read-only MAP_SHARED mapping from a
file.

Thanks,
Florian