On Mon, 17 May 2021 13:24:16 GMT, Jie Fu <ji...@openjdk.org> wrote: > Hi all, > > vmTestbase/vm/mlvm/anonloader/stress/oome/metaspace/Test.java fails on our > many-core machines due to `-XX:MaxRAMPercentage=0`. > This is because `MaxRAMPercentage` will be always 0 if JTREG_JOBS > 25 [1]. > > It can be reproduced by: `make test > TEST="vmTestbase/vm/mlvm/anonloader/stress/oome/metaspace/Test.java" > JTREG="JOBS=26"` on almost all machines. > > Setting `-XX:MaxRAMPercentage=0` on many-core machines seems unreasonable. > It would be better to fix it. > > Thanks. > Best regards, > Jie > > > [1] https://github.com/openjdk/jdk/blob/master/make/RunTests.gmk#L741
`-XX:MaxRAMPercentage` is actually `double`, so it can accept values below 1. The last time I looked into trouble like this, it was a problem with doing floating-point division in the make files -- not sure if something can be done about that. But my point is that the failing test -- is that the only test that fails? -- expects some heap size to accommodate Java allocations until the expected Metaspace OOM happens. In that case, the fix should be in the test itself. Because even if we do +1 to `MaxRAMPercentage`, it might still be not enough. ------------- PR: https://git.openjdk.java.net/jdk/pull/4062
