Hi all, I've tried to fix 8202466, but I do not yet certain which solution is the best for it. So I want your opinion for it.
https://bugs.openjdk.java.net/browse/JDK-8202466 David reports serviceability/tmtools/jstat/GcTest01.java failed in Mach5. It seems to appear on OS X only. He has shared jtreg report, and I found as below: ``` stdout: S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT CGC CGCT GCT 0.0 0.0 0.0 0.0 3072.0 0.0 11264.0 2825.6 9472.0 9003.3 1024.0 845.3 26 0.204 3 0.292 1 0.000 0.497 ``` YGCT: 0.204 FGCT: 0.292 CGCT: 0.000 GCT: 0.497 I guess this failure was caused by rounding error because (YGCT + FGCT + CGCT) < GCT. CGC is 1, so CGC operation might finish in very short time. GcTest01.java: http://hg.openjdk.java.net/jdk/jdk/file/4da7dce7e2bf/test/hotspot/jtreg/serviceability/tmtools/jstat/GcTest01.java#l57 GcCauseTest01.java: http://hg.openjdk.java.net/jdk/jdk/file/4da7dce7e2bf/test/hotspot/jtreg/serviceability/tmtools/jstat/GcCauseTest01.java#l53 GcTest01 and GcCauseTest01 are very similar, but GcCauseTest01 passed. Both tests use GcProvoker::provokeGc() to inflate memory usage. So I wonder why GcTest01 just only failed. I guess we might encounter similar issue(s) in the future if we get more fast machines. Hence I think we can take two approaches as below: 1. Add all tests in serviceability/tmtools/jstat to ProblemList. 2. Change all JstatGc*Tool to use custom jstat_options - to show raw values in PerfCounters What do you think? I can start to work for it if they are OK. Thanks, Yasumasa
