JDK-8252754 : Hash code calculation of JfrStackTrace is inconsistent
  • Type: Bug
  • Component: hotspot
  • Sub-Component: jfr
  • Affected Version: 16
  • Priority: P3
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2020-09-03
  • Updated: 2020-11-13
  • Resolved: 2020-09-03
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JDK 11 JDK 13 JDK 15 JDK 16 Other
11.0.10-oracleFixed 13.0.6Fixed 15.0.2Fixed 16 b15Fixed openjdk8u282Fixed
Related Reports
Relates :  
JDK-8250928 - JFR: Improve hash algorithm for stack traces
Description
After JDK-8250928 JfrStackTrace::record_safe is using new, improved hash code calculation. 
However, JfrStackTrace::record_thread was not updated to this calculation and we ended up with two ways a stack trace hash code will be calculated.
This situation does not sound right and JfrStackTrace::record_thread should be updated to use the new hash code calculation as well.
Comments
Fix request (13u) Requesting backport to 13u as follow-up fix for JDK-8250928. Minor adjustments needed to apply the patch. tier1 and jdk/jfr tests pass. RFR approval: http://mail.openjdk.java.net/pipermail/jdk-updates-dev/2020-November/004135.html
12-11-2020
[8u] Fix request This fix completes https://bugs.openjdk.java.net/browse/JDK-8250928 and makes the JFR stacktrace hash calculation consistent across different methods. The patch had to be adjusted for the fact that the hash code is calculate in jfrStackTraceRepository.cpp instead of jfrStackTrace.cpp https://mail.openjdk.java.net/pipermail/jdk8u-dev/2020-September/012714.html The fix is low risk, just making sure that the same hash code is calculated regardless of which method (record_safe or record_thread) is used. Tier1 and JFR tests are passing.
24-09-2020
[11u] Fix request This fix completes https://bugs.openjdk.java.net/browse/JDK-8250928 and makes the JFR stacktrace hash calculation consistent across different methods. The patch applies mostly cleanly with only hunk offsets adjustments. RFR: https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2020-September/003832.html The fix is low risk, just making sure that the same hash code is calculated regardless of which method (record_safe or record_thread) is used. Tier1 and JFR tests are passing.
18-09-2020
[15u] Fix request This fix completes https://bugs.openjdk.java.net/browse/JDK-8250928 and makes the JFR stacktrace hash calculation consistent across different methods. The patch applies cleanly. The fix is low risk, just making sure that the same hash code is calculated regardless of which method (record_safe or record_thread) is used. Tier1 and JFR tests are passing.
09-09-2020
URL: https://hg.openjdk.java.net/jdk/jdk/rev/9865aa072632 User: jbachorik Date: 2020-09-03 12:06:10 +0000
03-09-2020