On Fri, 12 Jul 2024 01:22:28 GMT, Guoxiong Li <g...@openjdk.org> wrote:
>> src/hotspot/share/gc/parallel/parallelScavengeHeap.cpp line 446: >> >>> 444: } >>> 445: return result; // Could be null if we are out of space. >>> 446: } >> >> I notice the method `PSOldGen::allocate` can expand the size of the old gen, >> but the method `PSYoungGen::allocate` can't expand the size of the young >> gen. It is similar to a bug [1] in Serial. Fortunately, the size of the >> young generation can be resized during Parallel GC if the option >> `UseAdaptiveSizePolicy` is `true`. When the `UseAdaptiveSizePolicy` is set >> to `false` manually by the user, I suspect it is a bug in Parallel because >> of the unexpanded young generation size. >> >> [1] https://bugs.openjdk.org/browse/JDK-8333386 > > @albertnetymk Do you think whether we need to expand young generation during > allocation (both Serial and Parallel)? In Serial, `UseAdaptiveSizePolicy` is > not used, so it is indeed a bug in Serial (the young generation can't be > resized and is always the initial size). Due to the internal structure (eden/survivor) of young-gen, it's not super easy to expand young-gen during allocation like old-gen. Need a dedicated ticket to properly evaluate its cost/benefit. > Serial (the young generation can't be resized and is always the initial size). That sounds like a definite bug; at least young-gen should be resizable during young-gc/full-gc. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20077#discussion_r1675613933
