[11] RFR(L) 8184349: There should be some verification that EnableJVMCI is disabled if a GC not supporting JVMCI is selected

[Vladimir Kozlov]

Thank you, Igor

On 6/13/18 1:06 PM, Igor Veresov wrote:
> Looks good.
> 
> I think if the future it would make more sense to be able to ask a JVMCI compiler what GCs does it support. But since there is just one implementation of a JVMCI compiler I guess it doesn’t matter much for now.

I think it could be difficult to implement and too late during startup 
because JVMCI compiler is Java code and GC will already be used when it 
is executed and could cause problem. Unless it has C++ code which checks 
GCs which Hotspot can call.

Thanks,
Vladimir

> 
> igor
> 
>> On May 3, 2018, at 3:12 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>>
>> http://cr.openjdk.java.net/~kvn/8184349/webrev.02/
>> https://bugs.openjdk.java.net/browse/JDK-8184349
>>
>> Recent testing problem after Graal dropped CMS (throw exception) made this RFE more urgent. I decided to fix it.
>>
>> The main fix is for JVMCI to check if GC is supported and exit VM with error if not [1]. It is called from Arguments::apply_ergo() after GC is selected in GCConfig::initialize().
>>
>> Main changes are refactoring.
>>
>> I used this opportunity (inspired by GCConfig) to move compiler related code from arguments.cpp file into compilerDefinitions.* files. And renamed it to compilerConfig.*.
>>
>> Two new CompilerConfig methods check_comp_args_consistency() and CompilerConfig::ergo_initialize() are called from arguments.cpp.
>>
>> The rest are test fixing. Mostly to not run CMS GC with Graal JIT.
>>
>> One test CheckCompileThresholdScaling.java was modified because I skipped scaling compiler threshold in Interpreter mode (CompileThreshold = 0).
>>
>> For tests which use CMS I added @requires !vm.graal.enabled.
>> Unfortunately I did not fix all tests which use CMS. Some tests have several @run commands for each GC. And some tests fork new process to test different GCs. Changes for those tests are more complicated and I filed follow up bug 8202611 [2] I will fix after this.
>>
>> Tested tier1,tier2,tier2-graal
>>
>> -- 
>> Thanks,
>> Vladimir
>>
>> [1] http://cr.openjdk.java.net/~kvn/8184349/webrev.02/src/hotspot/share/jvmci/jvmci_globals.cpp.udiff.html
>> [2] https://bugs.openjdk.java.net/browse/JDK-8202611
>