RFR: 8058176: [mlvm] tests should not allow code cache exhaustion [v2]

[Igor Ignatyev]

On Wed, 17 Feb 2021 15:34:41 GMT, Evgeny Nikitin <enikitin at openjdk.org> wrote:

>> o/c they grow, b/c we use them for compiled code *and* if there is no space in non-nmethod heap, we use them for adapters as well, so I guess that the growth that you see is already after non-nmethod heap got exhausted. I'd recommend you simply use the sum of all available code-heaps (this will increase the possibility of false-positive results due to segmentation, but I don't think it matters much here).
>
> Well, seems like rebalancing doesn't works that good. Here's a sample failure with plenty of free space in the non-nmethods heap:
> 
> [8.230s][warning][codecache] CodeHeap 'non-profiled nmethods' is full. Compiler has been disabled.
> [8.230s][warning][codecache] Try increasing the code heap size using -XX:NonProfiledCodeHeapSize=
> Java HotSpot(TM) 64-Bit Server VM warning: CodeHeap 'non-profiled nmethods' is full. Compiler has been disabled.
> Java HotSpot(TM) 64-Bit Server VM warning: Try increasing the code heap size using -XX:NonProfiledCodeHeapSize=
> CodeHeap 'non-profiled nmethods': size=8192Kb used=8191Kb max_used=8191Kb free=0Kb   << Exhausted
> CodeHeap 'profiled nmethods': size=8192Kb used=8191Kb max_used=8191Kb free=0Kb       << Exhausted
> CodeHeap 'non-nmethods': size=102400Kb used=18343Kb max_used=18343Kb free=84056Kb    << 84Mb of free space
> 
> # ERROR: Caught exception in Thread[Thread-41,5,MainThreadGroup]
> ...
> # ERROR: Caused by: java.lang.VirtualMachineError: Out of space in CodeCache for method handle intrinsic
> The sum monitoring won't help here either. I've added non-nmethods heap to the monitoring, just to be sure.

hm... that can mean that there is a product bug (or my recollections about code heaps aren't as good as I thought).

@TobiHartmann , @iwanowww, could you please take a look? Evgeny's observations suggest that method handle intrinsics use `non-profiled nmethods` and `profiled nmethods` heaps and not `non-nmethods` heap despite the fact that the last one has plenty of free space. my understanding is/was that we should have used `non-nmethods` heap for MH intrinsic 1st and if it's exhausted start to use the other heaps.

Thanks,
-- Igor

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PR: https://git.openjdk.java.net/jdk/pull/2523