On Sun, 6 Jul 2025 21:07:26 GMT, Albert Mingkun Yang <ay...@openjdk.org> wrote:
>> src/hotspot/share/gc/parallel/psParallelCompact.cpp line 898: >> >>> 896: size_t target_capacity_bytes = total_live_words * HeapWordSize >>> 897: + old_space->capacity_in_bytes() * >>> (MarkSweepDeadRatio / 100.0) >>> 898: + SpaceAlignment; >> >> Why add `SpaceAlignment`, not `align_up` to `SpaceAlignment`? > > The alignment is handled inside the callee. I just wanna leave a minimal > delta in the old-gen so that old-gen is not completely full. Otherwise, the > next young-gc can not promote anything and will be upgraded to full-gc > directly. This is mostly for `UseAdaptiveSizePolicy == false`; if enabled, > old-gen will also be resized after full-gc. After [JDK-8328744](https://bugs.openjdk.org/browse/JDK-8328744), it no longer uses old-gen capacity, but max old-gen size to estimate if promotion can succeed. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/25000#discussion_r2188764546
