RFR: JDK-8327769: jcmd GC.heap_dump without options should write to location given by -XX:HeapDumpPath, if set [v4]

[Christoph Langer]

On Thu, 14 Mar 2024 16:54:48 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

>> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   add test HeapDumpJcmdPresetPathTest
>
> src/hotspot/share/runtime/globals.hpp line 565:
> 
>> 563:           "triggered by jcmd GC.heap_dump without specifying a path, "      \
>> 564:           "the path (filename or directory) of the dump file "              \
>> 565:           "(defaults to java_pid<pid>.hprof in the working directory)")     \
> 
> This incorrectly leads one to conclude that if HeapDumpPath is not specified and GC.heap_dump is used without specifying a path, the default will be java_pid<pid>.hprof in the working directory. That's not the case. The jcmd will produce an error because it requires that either HeapDumpPath be specified or a filename be specified as a jcmd argument (I'm not sure why the jcmd does not default to java_pid<pid>.hprof) 
> 
> Also, if you are cleaning up this text, I would suggest changing "is on" to "is enabled".  Same for HeapDumpGzipLevel below.

Yes, why not make java_pid<pid>.hprof in the working directory the default if calling jcmd GC.heap_dump without specifying a path? Would there be any problem with that approach?

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PR Review Comment: https://git.openjdk.org/jdk/pull/18190#discussion_r1525832839