On Mon, 19 Feb 2024 05:52:22 GMT, Varada M <vara...@openjdk.org> wrote:
> DeCapo Benchmark Results (3 runs) : > > Before : > ===== DaCapo 9.12 h2 PASSED in 281402 msec ===== > ===== DaCapo 9.12 h2 PASSED in 269818 msec ===== > ===== DaCapo 9.12 h2 PASSED in 279279 msec ===== > > After: > ===== DaCapo 9.12 h2 PASSED in 279192 msec ===== > ===== DaCapo 9.12 h2 PASSED in 269769 msec ===== > ===== DaCapo 9.12 h2 PASSED in 271577 msec ===== > > Environmental variables LDR_CNTRL and MALLOCOPTIONS has caused > test/jdk/java/lang/ProcessBuilder/Basic.java failure. > Additional environmental variables has to removed from > removeAixExpectedVars(). > > JBS Issue : [JDK-8252802](https://bugs.openjdk.org/browse/JDK-8252802) I don't think this works as intended. IIRC, both variables must be set *before process invocation*. Setting them inside the launcher will only affect child processes. The dacapo results posted seem to support this, they seem random-ish to me. Note that we already use 64KB pages for all large memory regions (everything that goes through `os::reserve_memory`). So, while the value of LDRCNTRL is not nil, it is very diminished. Mostly just the Heap is affected. But I would not change defaults for options like these anyway, especially not hard-coded. These knobs have far-ranging implications. If we want that, we need to investigate carefully. (for example: would using 64KB pages increase average heap size? Possibly, depending on the implementation. But AIX still has this problem where the heap can only live in the break and can bump against low-hanging regions. So, AIX is especially vulnerable against any changes that increase average heap usage) ------------- PR Comment: https://git.openjdk.org/jdk/pull/17906#issuecomment-1953643518
