RFR: 8257848: -XX:CompileCommand=blackhole, * should be diagnostic [v4]
Vladimir Kozlov
kvn at openjdk.java.net
Mon Dec 7 20:51:14 UTC 2020
On Mon, 7 Dec 2020 19:52:31 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:
>> This follows up on retroactive CSR review comments (JDK-8257827). As the result of discussion, it is decided to demote the "blackhole" compile command to diagnostic. Examples:
>>
>> $ build/linux-x86_64-server-release/images/jdk/bin/java -Xcomp -XX:CompileCommand=quiet -XX:CompileCommand=blackhole,java/lang/Object.toString
>> OpenJDK 64-Bit Server VM warning: Blackhole compile option is diagnostic and must be enabled via -XX:+UnlockDiagnosticVMOptions
>>
>> $ build/linux-x86_64-server-release/images/jdk/bin/java -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:CompileCommand=quiet -XX:CompileCommand=blackhole,java/lang/Object.toString
>> OpenJDK 64-Bit Server VM warning: Blackhole compile option only works for methods with void type: java.lang.Object.toString()Ljava/lang/String;
>>
>> New test verifies the locking/unlocking of the command.
>>
>> Testing:
>> - [x] ad-hoc `compiler/blackhole` test
>> - [x] validation runs with JMH
>> - [ ] runs in `tier1` (needs #1654 to be merged)
>
> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
>
> Check blackhole unlocking at startup
Do you need to update blackhole tests to add -XX:+UnlockDiagnosticVMOptions?
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PR: https://git.openjdk.java.net/jdk/pull/1674
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