Details
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Sub-task
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Resolution: Delivered
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P4
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22
Description
During the Remark pause G1 adjusts the Java heap size to keep a minimum and maximum amount of free regions as set via the `-XX:MinHeapFreeRatio` and `-XX:MaxHeapFreeRatio` options.
Before this change, G1 considered Eden regions as occupied (full) for this calculation. This makes heap sizing very dependent on current Eden occupancy, although after the next garbage collection these regions will be empty. With this change, Eden regions are considered as empty (free) for matters of Java heap sizing.
This new policy also aligns Java heap sizing to full GC heap sizing.
The effect is that G1 now expands the Java heap less aggressively and more deterministically, with corresponding memory savings but potentially executing more garbage collections.
Before this change, G1 considered Eden regions as occupied (full) for this calculation. This makes heap sizing very dependent on current Eden occupancy, although after the next garbage collection these regions will be empty. With this change, Eden regions are considered as empty (free) for matters of Java heap sizing.
This new policy also aligns Java heap sizing to full GC heap sizing.
The effect is that G1 now expands the Java heap less aggressively and more deterministically, with corresponding memory savings but potentially executing more garbage collections.