JDK-8221392 : Reduce ConcurrentGCThreads spinning during start up
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 8,11,13
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2019-03-25
  • Updated: 2019-11-22
  • Resolved: 2019-03-27
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JDK 13
13 b14Fixed
Related Reports
Duplicate :  
JDK-8148359 - Improve concurrent mark thread synchronization on startup
Description
During startup, ConcurrentGCThreads end up in a loop sleeping for 1ms over and over (typically 30-50 times), until is_init_completed() is true. This is not optimal, and we should instead have them wait until they are signaled.
Comments
Did some measurements with Shenandoah, and there is no conclusive evidence it improves startup/efficiency for us to care. Dropping this from 11u backport queue. We can reconsider if there is new need/evidence appears.
17-09-2019
Fix Request (11u) This improves startup of GC implementation with concurrent control threads. Patch does not apply cleanly to 11u, because of context changes. Patched builds pass tier1 tests. 11u RFR: https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2019-June/001326.html
26-06-2019