JDK-8269423 : ZGC: Support pinned Object and remove/simplify GCLocker usage in ZGC
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 18
  • Priority: P4
  • Status: Open
  • Resolution: Unresolved
  • Submitted: 2021-06-26
  • Updated: 2021-07-02
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Other
tbdUnresolved
Related Reports
Relates :  
JDK-8269419 - G1: Support pinned Ojbect and remove/simplify GCLocker usage in G1
Sub Tasks
JDK-8269651 :  
ZGC: Optimize away gc locker in mark start - Closed
Description
As the title suggest, use object pinning instead of gclocker for objects that should not move.
Comments
Keep the issue open, but close the PR for now, and will come back then to investigate the issue to see if there will be better solution. "I suggest we close this PR for now and revisit this once we have the generational work in place, since that might open up some doors for this." - Per Liden
02-07-2021
I will create a PR for discussion convenience. This PR is not an real intention to push current implementation, and current implementation does not support ZVerifyViews. Let's see if this solution is feasible and how to support ZVerifyViews efficiently.
01-07-2021
Thanks. I have put some comments at JDK-8269651, would like to hear your comments on JDK-8269651 first.
01-07-2021
Feel free to provide mode details on what you had in mind here. I can just add that adding support for object pinning has been considered and abandoned since is it interacts badly with multi-mapping and a consistent use of the current heap view. The ongoing work to introduce generations in ZGC will most likely remove some of these barriers, but until then I don't think this is something we want to peruse.
30-06-2021