RFR: 8273112: -Xloggc and -Xlog should override -verbose

[Mikhailo Seledtsov]

On Mon, 30 Aug 2021 07:09:54 GMT, Xiaowei Lu <github.com+39413832+weixlu at openjdk.org> wrote:

> According to java 16 specifications for java command (https://docs.oracle.com/en/java/javase/16/docs/specs/man/java.html), the command line option -Xloggc should override -verbose:gc if both options are given with the same java command. However, gc information still outputs to console even if gc log file is specified.
> 
> $java -Xloggc:gc.log -verbose:gc -version
> [0.000s][warning][gc] -Xloggc is deprecated. Will use -Xlog:gc:gc.log instead.
> [0.003s][info ][gc] Using G1
> $cat gc.log
> [0.003s][info][gc] Using G1
> 
> In addition, since -Xloggc:filename is replaced by -Xlog:gc:filename, can we assume that -Xlog:gc:filename should override -verbose:gc as -Xloggc:filename? Currently, gclog still outputs to both stdout and file if -Xlog and -verbose are given with the same java command.
> 
> $java -Xlog:gc:gc.log -verbose:gc -version
> [0.003s][info][gc] Using G1
> $cat gc.log
> [0.003s][info][gc] Using G1
> 
> As a result, we propose to put off the log configuration of -verbose option until we are confident that there isn’t -Xloggc or -Xlog options.

Please consider providing a test for this change, or modifying an existing test with this test case.

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PR: https://git.openjdk.java.net/jdk/pull/5295