RFR: 8256416: ZGC: Lower ZMarkCompleteTimeout

Tue Nov 17 16:03:14 UTC 2020

With JEP-376 integrated, the ZMarkCompleteTimeout now essentially dictates how long the max GC pause will be in ZGC. Since our pauses are now on the order of 50-100us I propose we lower the ZMarkCompleteTimeout to 200us (instead of 1ms).

Running the usual benchmarks, I can see no difference in number of mark continues, which suggests 200us is long enough to handle all common cases.

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Commit messages:
 - 8256416: ZGC: Lower ZMarkCompleteTimeout

Changes: https://git.openjdk.java.net/jdk/pull/1263/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1263&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256416
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1263.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1263/head:pull/1263

PR: https://git.openjdk.java.net/jdk/pull/1263