JDK-8215624 : Add parallel heap iteration for jmap –histo
  • Type: Sub-task
  • Component: core-svc
  • Sub-Component: tools
  • Affected Version: 16
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2018-12-19
  • Updated: 2022-01-14
  • Resolved: 2020-08-13
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JDK 11 JDK 16
11.0.14Fixed 16 b12Fixed
Related Reports
CSR :  
JDK-8239290 - Add parallel heap iteration for jmap -histo
Duplicate :  
JDK-8253043 - Parallel heap inspection for G1
Relates :  
JDK-8261482 - Adjust jmap histo command to accept noparallel option to inspect heap serially
Relates :  
JDK-8251570 - JDK-8215624 causes assert(worker_id < _n_workers) failed: Invalid worker_id
Relates :  
JDK-8280002 - jmap -histo may leak stream
Relates :  
JDK-8253763 - ParallelObjectIterator should have virtual destructor
Description
Add a parallel heap iteration for jmap --histo will allow the system to not be done sequentially
Comments
Fix Request (11u) Please approve backporting this to OpenJDK 11u. The PR is https://github.com/openjdk/jdk11u-dev/pull/127. We believe this could help imporve the performance of heap inspection, especially for large heap scenario. We believe the downport risk is low as this PR only introduce new options, and most of the code are same as from jdk-master, we only made the change that necessary for downporting. Thanks! Lin
08-09-2021
URL: https://hg.openjdk.java.net/jdk/jdk/rev/b1afb7c82d59 User: dcubed Date: 2020-08-13 21:50:00 +0000 Added the above notification in regular format for automatic parsers.
15-08-2020
Corrected commit: http://hg.openjdk.java.net/jdk/jdk/rev/b1afb7c82d59
13-08-2020
Commit incorrectly attributed to 'phh' as author. 'lzang' is the actual author.
13-08-2020
URL: https://hg.openjdk.java.net/jdk/jdk/rev/5036ca733469 User: phh Date: 2020-08-13 18:32:00 +0000
13-08-2020
I have deleted the description of concurrency. Since the jmap -histo holds heap lock when iterating heap, so IMO it is already concurrent, but this changeset has no modification about the concurrentcy behavior, so I omit the description. Thanks.
08-07-2020
According to the summary, this issue is about "parallel heap iteration for jmap –histo" while the description speaks about "..allowing the program to continue its "job" while the jmap --histo is performed". This sounds like this change not only wants to parallelize "jmap -histo", but also make it run concurrently. Is that really true and the intention of this issue? If not please update the description accordingly.
08-07-2020
webrev at http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/
20-02-2020