8286865: vmTestbase/vm/mlvm/meth/stress/jni/nativeAndMH/Test.java fails with Out of space in CodeCache

[rsunderbabu]

MethodHandle invocations with Xcomp are filling up CodeCache quickly in the test, especially in machines with high number of processors.
It is possible to measure code cache consumption per invocation, estimate overall consumption and bail out before CodeCache runs out of memory.
But it is much simpler to exclude the test for Xcomp flag.

Additional Change: MethodHandles.lookup was done unnecessarily invoked for all iterations. Replaced it with single invocation.

PS: This issue is not seen in JDK 20 and above, possibly due to JDK-8290025, but the exclusion guards against vagaries of CodeCache management.

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Issue

• JDK-8286865: vmTestbase/vm/mlvm/meth/stress/jni/nativeAndMH/Test.java fails with Out of space in CodeCache (Bug - P4)

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[turbanoff]

Suggested change

	} catch(Exception ex) {
	} catch (Exception ex) {

[dean-long]

-Xcomp is a useful stress flag, and this test is meant to stress MHs, not the code cache, so can we increase the code cache size enough to let it pass with -Xcomp?

[rsunderbabu]

-Xcomp is a useful stress flag, and this test is meant to stress MHs, not the code cache, so can we increase the code cache size enough to let it pass with -Xcomp?

The number of iterations are proportional to number of CPUs. so we cannot predict the required cache size.
Another alternative is to cap the number of CPU based scaling to some number. If the number is capped, someone might doubt if we have stressed MHs enough.