RFR: 8333786: Serial: Remove SerialHeap::_incremental_collection_failed [v3]

[Albert Mingkun Yang]

On Fri, 14 Jun 2024 11:41:34 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> What does "the heap can be too full to be handled properly by full-gc" mean?

https://bugs.openjdk.org/browse/JDK-8333928 is an example. (I also encountered sth similar locally, when supporting allocation-in-from.)

> Can you describe the case, the current behavior and the new behavior in more detail?

The master behavior is about increasing probability of surviving tight heap, by allocating-in-from. (Usually, one allocates only in eden for young-gen.) The new behavior is about removing the special case of allocation-in-from, streamlining the allocation-logic.

> Is this really required? Why remove functionality and not fix?

One can try to fix the support for allocating-in-from, but introduces significant complexity (full-gc needs to very careful about deciding where objs are forwarded to avoid fragmentation, instead of current simple sliding-logic).

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PR Comment: https://git.openjdk.org/jdk/pull/19594#issuecomment-2167888226