JDK-8271870 : G1: Add objArray splitting when scanning object with evacuation failure
Type:Enhancement
Component:hotspot
Sub-Component:gc
Affected Version:18
Priority:P4
Status:Open
Resolution:Unresolved
Submitted:2021-08-04
Updated:2024-09-13
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During evacuation failure handling G1 does not split object arrays that failed copying for better parallelism like in the regular object copy path.
Comments
With JDK-8337709 this optimzation should now be doable.
13-09-2024
Objects in young gen can be half a region size. Half a region size is 16M (well, 256M soon), ie. up to ~4M (64M) pointers; currently these pointers are scanned by a single thread, without the task stepper - i.e. basically copying that array onto the task queue.
That seems inefficient.
Note that this is (probably) not easy to do, so let's not make this top priority (and optional) for a first cut.
09-11-2021
Not quite sure whether we need to split an array which failed evacuation.