RFR: 8260349: Cannot programmatically retrieve Metaspace max set via JAVA_TOOL_OPTIONS [v4]

[Aleksey Shipilev]

On Thu, 28 Jan 2021 10:50:24 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> A simple but long standing bug whereby the MemoryPool MXBean only sees the value of MaxMetaspaceSize if it was set directly on the command-line and not by other means (e.g. env var).
>> 
>> Fix is to check !FLAG_IS_DEFAULT rather than FLAG_IS_CMDLINE.
>> 
>> Expanded regression test added (based on the reproducer in the JBS issue) that checks all the ways to set the flag: cmd-line, env-var, hotspotrc file
>> 
>> Testing: regression test (before and after fix)
>>              tiers 1-3 (in progress)
>> 
>> Thanks,
>> David
>
> David Holmes has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:
> 
>  - Further formatting updates from Aleksey
>  - Merge branch 'master' into 8260349
>  - Cleaned up test formatting based on Aleksey's review
>  - Added missing test case for flag not set
>  - Boost max from 1MB to 9MB as 1MB was too low for Aarch64 to startup
>  - Reduced test code using loop for env-vars
>  - 8260349: Cannot programmatically retrieve Metaspace max set via JAVA_TOOLS_OPTIONS

Good. Minor nits to fix before push?

test/hotspot/jtreg/runtime/Metaspace/MaxMetaspaceSizeEnvVarTest.java line 75:

> 73: 
> 74:         int test = 1;
> 75:         report("Test " + test +": flag not set");

Missing space here: `+"`

test/hotspot/jtreg/runtime/Metaspace/MaxMetaspaceSizeEnvVarTest.java line 81:

> 79:         test++;
> 80: 
> 81:         report("Test " + test +": normal command-line flag");

Missing space here: `+"`

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Marked as reviewed by shade (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/2275