JDK-8261943 : add new attach API command dumpheapext for passing more options to jvm
  • Type: Sub-task
  • Component: tools
  • Priority: P4
  • Status: Closed
  • Resolution: Won't Fix
  • Submitted: 2021-02-18
  • Updated: 2021-04-14
  • Resolved: 2021-04-14
Related Reports
CSR :  
JDK-8262162 - add new attach API command dumpheapext for passing more options to jvm
Description
The current implement of jcmd - jmap command could only pass less than 4 arguments to jvm. 
With the introduction of "parallel=[N]" option, the "jmap -dump" option could have 4 arguments: "file=" ,  "-live", "gz=" and "parallel=". 
To avoid the compatibility issue between old/new jmap and old/new jvm, a new attach API command "dumpheapext" needs to be added for passing extra arguments.
Comments
As discussed in https://github.com/openjdk/jdk/pull/2261. It is hard for user to tune the thread number used for parallel heap dump. So we decide not to expose the `parallel=<N>`option for jmap -dump. And hence there is no need to extend jcmd internal command at present. Close this issue and related CSR, it could be reopened when there is new requirement for adding more arguments to jcmd jmap command. Thanks.
14-04-2021