JDK-8231264 : Implementation of JEP 374: Disable biased-locking and deprecate all flags related to biased-locking
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 15
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2019-09-19
  • Updated: 2020-11-16
  • Resolved: 2020-05-13
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JDK 15
15 b24Fixed
Related Reports
CSR :  
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Sub Tasks
JDK-8234205 :  
JDK-8234206 :  
See "JEP 374: Disable and Deprecate Biased Locking" - JDK-8235256
URL: https://hg.openjdk.java.net/jdk/jdk/rev/4a2ee50baa47 User: pchilanomate Date: 2020-05-13 15:55:05 +0000

Changed the synopsis to match the more usual pattern for issues related to JEPs. We can fill in the number once the JEP is accepted.

Discussion related to this RFE: https://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2019-November/037023.html Some results of performance testing at Google: On 2/11/20 1:35 PM, Man Cao wrote: > Hi, > > We are concerned about the deprecation of biased locking, so we asked a > colleague (Fred Kuipers <fredjk@google.com>) > to help us experiment with -XX:-UseBiasedLocking on an important production > service. > Overall, the results are supportive of disabling UseBiasedLocking. > > The experiments are based on JDK 11.0.5 running with G1 and > -XX:-TieredCompilation on x86_64-based Linux. > There are 7 servers for the service, with heap sizes ranging 3G-15G, > serving real production traffic. > Production traffic is split into two shards for each server, one shard > running with -XX:+UseBiasedLocking, > the other with -XX:-UseBiasedLocking. The production team uses the exact > same methodology to evaluate > performance issues in their routine release process. > > 3 out of the 7 servers see no difference. The other 4 servers see potential > improvement (reduction) in CPU usage > with -XX:-UseBiasedLocking. This would translate to improved throughput for > us. > > -Man

Reopen based on [~dcubed] comments. We can still use this RFE.

[~pchilanomate] - you can file a JEP and still use this bug as the implementation RFE... I recommend reopening this bug.

This would need a JEP to proceed.