On Thu, 6 Aug 2026 23:17:57 GMT, Shiv Shah <[email protected]> wrote: >> The test fails intermittently with OutOfMemoryError under -Xcheck:jni >> -XX:+UseZGC (the original report also had -XX:+ZGenerational, which is gone >> since JEP 490). Reproduced at about 2%: 6 of 300 runs on four hosts, all >> with the original signature. >> >> GC logs from the failing runs show the 512m heap reaching 100% with ZGC in >> back-to-back allocation-stall collections that reclaim almost nothing, >> ending in the OOME while Allocator.helper grows its list. The sampling >> agent holds jweaks on the sampled objects, which keeps the transient garbage >> alive until a major collection runs. The test's actual live set is only >> about 20MB. >> >> Fix: bump the test heap from 512m to 1g. >> >> Testing: 500 default-config runs at 1g all pass. The failing configuration >> at 1g (501 runs) had 2 OOME failures, about 0.4% vs 2% at 512m. >> >> >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > Shiv Shah has updated the pull request incrementally with one additional > commit since the last revision: > > Remove bug tag and update copyright year
test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java line 33: > 31: * @requires vm.jvmti > 32: * @compile HeapMonitorThreadTest.java > 33: * @run main/othervm/native/timeout=480 -Xmx1g -agentlib:HeapMonitorTest > MyPackage.HeapMonitorThreadTest Should we enable the gc log by default. That will be convenient to diagnose the similar OOME issue if the same problem occur again. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/32229#discussion_r3755871418
